Dietary Guidelines Advisory Committee Meeting
Sponsored by the
U.S. Department of Health and Human Services (HHS)
U.S. Department of Agriculture (USDA)
Held at the
Hotel Inn Washington-Georgetown
March 30-31, 2004
Tuesday, March 30
Dietary Guidelines Advisory Committee: Dr. Janet C. King
(Chair), Dr. Lawrence J. Appel, Dr. Yvonne L. Bronner, Dr. Benjamin
Caballero, Dr. Carlos A. Camargo Jr., Dr. Fergus M. Clydesdale, Dr.
Vay Liang W. Go, Dr. Penny M. Kris-Etherton, Dr. Joanne R. Lupton, Dr.
Theresa A. Nicklas, Dr. Russell R. Pate, Dr. F. Xavier Pi-Sunyer, Dr.
Connie M. Weaver
Executive Secretaries: Ms. Carole Davis, Ms. Kathryn McMurry,
Dr. Pamela Pehrsson, Dr. Karyl Thomas Rattay
Others: Ms. Carter Blakey, Dr. Eric Hentges, Dr. Carol Suitor
Welcome and Introductions
Dr. Janet C. King, Chair, Dietary Guidelines Advisory Committee,
welcomed Committee members, staff, and observers to the third meeting
of the Advisory Committee and summarized the Committee's work since
its first meeting in September. She noted that Committee members had
worked extensively since the January meeting to draft a wide range of
conclusive statements, including the rationale and scientific support
for each. She acknowledged the help and input provided by scientific
writer, Dr. Carol Suitor, who reviewed and edited the draft statements
for consistency and clarity.
Dr. King noted that the purpose of this meeting was to discuss the
work of the Subcommittees in order to come to an agreement regarding
the major scientific conclusions and how to translate them into
specific recommendations. She urged Committee members to challenge
each other to ensure that the conclusions are based on the strongest
Dr. King stated that the full draft of the Committee's report would be
reviewed and refined at the fourth and final meeting in May and that
the Committee was on schedule to submit the report to the HHS and USDA
Secretaries in June 2004. She thanked the Committee for its hard work
and the staff for their strong support.
Dr. King then reviewed the agenda for the day. In the morning session,
the Committee would hear two expert presentations on energy density
and another expert presentation on physical activity and the new
recommendations from the Centers for Disease Control and Prevention
(CDC). In the afternoon, the Committee would discuss the conclusive
statements developed by three Subcommittees (Carbohydrates, Fatty
Acids, and Macronutrients). Dr. King hoped there would be time at the
end of the day for a general discussion of overarching issues, the
format of the final report, and next steps. The second day of the
meeting would be devoted to discussion of conclusive statements
drafted by the remaining Subcommittees. Dr. King's goal for the
meeting was for the Committee to reach agreement on the scientific
conclusions by the end of the meeting.
Dr. King concluded by reminding the Committee that the role of outside
experts was to help the Committee and the Subcommittees understand the
scientific context of a particular issue, and that it was the
Committee's responsibility to develop recommendations based on the
Presentations and Discussion: Energy Density
B.J. Rolls and R. Mattes
Dr. King thanked Dr. Rolls and Dr. Mattes for coming to the
meeting. She noted that there would be time for discussion after both
speakers had made their presentations. Dr. King then introduced the
first speaker, Dr. Barbara J. Rolls, Professor of Nutritional
Sciences at the Pennsylvania State University. Dr. Rolls is
a specialist in the controls of food and fluid intake, especially as
they relate to obesity, eating disorders, and aging. She has served as
a member of the Advisory Council of the National Institute of Diabetes
and Digestive and Kidney Disease (NIDDK) and was also a member of
NIH's National Task Force on Obesity.
Dr. Rolls stated that her presentation would address four important
dietary issues related to weight management: portion size, energy
density, the role of fruits and vegetables, and maintenance of weight
Dr. Rolls began by noting that portion sizes have increased steadily
since the mid-1970s and cited data from two large epidemiological
studies showing that people are consuming larger portions, both at
home and when eating out. She pointed out that these studies did not
examine the relationship between portion size and Body Mass Index
(BMI) and that studies were needed in that area.
Dr. Rolls presented an overview of several studies conducted at
Pennsylvania State University, all of which found that increasing the
portion size increased the amount that people consumed. In one study,
increasing the portion size of a restaurant entrée at lunch resulted
in increased intake of all components of the meal, including side
dishes. The subjects felt that the original and larger portions were
Another study found that the effects persisted when portion sizes of
all foods for all meals were increased over two days. On average,
women consumed an additional 530 calories each day, for a cumulative
total of 1,000 calories over two days; men consumed an additional 800
calories per day, for a cumulative total of 1,060 calories. There was
no decrease in the effect over time. Dr. Rolls noted that she and her
colleagues were currently conducting longer-term studies, in which the
increased portion sizes would be maintained over a longer period.
Dr. Rolls stressed that advice to eat less is not effective for weight
management because portion size is only one variable; the other
variable is energy density (energy per unit weight). She presented a
study in which three different portion sizes were served of
high-energy dense and low energy-dense casseroles. The study found
that increased portion size and increased energy density were both
associated with increased intake. Moreover, the effects of portion
size and energy density were additive.
Another study, which is undergoing peer-review, found that eating a
large, low-calorie solid first course was associated with lower energy
intake for the whole meal, while a large, high energy-dense first
course was associated with higher energy intake. Dr. Roll noted that
these findings indicate that the interactions between portion size and
energy density are complex.
Dr. Rolls prefaced her discussion of energy density by discussing
dietary fat. Referring to the 1998 National Heart, Lung, and Blood
Institute (NHLBI) Clinical Guidelines on the Identification,
Evaluation, and Treatment of Overweight and Obesity, she noted
that while lower-fat diets led to reduced energy intake, lower-fat
diets combined with caloric reduction produced greater weight loss
than lower-fat diets alone. Dr. Rolls posited that while the reduced
intake associated with low-fat diets could be due to lower
palatability or greater satiety, it could also be due to the decreased
energy density of those diets.
Dr. Rolls stated that a number of studies had indicated that the daily
amount of food consumed was more consistent than energy intake. She
presented data from a 1983 hospital-based food intake study, which
showed that people on an ad-lib diet tended to consume a consistent
weight or volume of food, regardless of the energy density of the
Dr. Rolls pointed out that water has the greatest impact on energy
density, yet it had been overlooked in most food intake studies. Using
the example of raisins and grapes, she noted that adding water reduces
energy density, even of high-fat foods.
Dr. Rolls cited a study in which researchers varied the energy density
of a mixed dish by varying the portion of vegetables in order to
determine whether energy density, independent of macronutrient
content, could affect how much people eat. The study found that while
people consumed the same amount of food, by weight, those who ate the
low-energy dense dish consumed 30 percent fewer calories than those
who ate the high-energy dense dish. Dr. Rolls stated that numerous
studies had confirmed that decreasing fat content and holding energy
density constant produced no effect on ad-lib energy intake, while
decreasing energy density and holding macronutrients constant was
associated with reduction in intake.
Based on that evidence, Dr. Rolls stated that decreasing the energy
density of the diet produced satisfying portions for the same number
of calories. She cited fruits, vegetables, whole grains, lean protein,
broth-based soups, and water- rich foods as the key ingredients for
manipulating energy density and presented several studies that
supported a role for energy density in weight management. She noted
that it was difficult to separate the effects of fat from those of
energy density in most studies.
Dr. Rolls stated that while more controlled studies were needed, there
is sufficient data to show that fruits and vegetables are an important
element of weight management. They help people avoid feelings of
deprivation, they enhance satiety, and they allow positive messaging
about what people should be eating rather than what they cannot eat.
She cited studies showing that individuals on a reduced-fat diet who
consumed additional fruits and vegetables lost more weight than those
on the reduced-fat diet alone. Citing a study with children and
parents, she noted that positive messages to eat more fruit and
vegetables were associated with significantly greater weight loss than
restrictive messages to eat less fat and sugar.
Dr. Rolls acknowledged that maintaining weight loss was more
challenging than losing weight and that it was especially difficult
without reinforcement. She cited a study showing that
cognitive-behavioral therapy and enhanced food monitoring in
combination were more effective than either approach alone. Adding
instruction on low-energy dense foods to those treatments provided the
best maintenance of weight loss over 6 months. She also presented
preliminary findings of an ongoing clinical trial in her lab comparing
reduced-energy density diets to reduced-fat diets.
Given the difficulty of maintaining weight loss, Dr. Rolls
emphasized the importance of establishing eating and activity patterns
that can be sustained and of reinforcing positive messages during
maintenance periods. She recommended a reduced-fat, reduced-energy
density eating pattern that encouraged consumption of vegetables,
fruits, whole grains, and lean protein. Because this eating pattern
could also prevent weight gain, Dr. Rolls suggested that it should be
introduced in childhood.
Dr. Rolls concluded by stating that balance, variety, and moderation
were especially important for those on a calorie-restricted diet. She
stressed that emphasizing quality rather than quantity would help
consumers make nutritious choices and eat appropriate amounts, and she
reiterated the need to learn more about how to control hunger and
promote satiety while managing calories.
Dr. King thanked Dr. Rolls for her presentation and introduced Dr.
Richard Mattes, Professor of Foods & Nutrition at Purdue University.
She noted that Dr. Mattes also serves as Associate Professor of
Medicine at the Indiana University School of Medicine and is an
Affiliated Scientist at the Monell Chemical Senses Center. He has
conducted extensive research on hunger and satiety, regulation of food
intake in humans, food preferences, human cephalic phase responses,
and taste and smell.
Dr. Mattes began by stating that energy density was not a reliable
basis for establishing dietary guidelines. He proposed that energy
density should be defined in terms of mass rather than volume, because
volume is transient while mass is constant, and because volume affects
only the cognitive and gastric aspects of eating and has very limited
influence from the intestinal phase through the post-ingestive phases.
He cited a study that manipulated both the volume and the energy
density of food, which found that while high-volume foods were
associated with greater suppression of hunger and greater fullness
ratings, volume was not related to food intake at a subsequent meal or
to daily food intake. Energy density was associated with intake at the
test meal, but it had no effect on daily food intake. Dr. Mattes
concluded that volume appeared to have a greater impact than energy
density on appetite, where cognitive factors are involved, but less
impact on actual intake.
Dr. Mattes stated that while there could be some residual effects of
volume once a food is ingested, it was unlikely that the stomach
played a key role in regulating appetite. He cited studies with
gastrectomized subjects, which found that the appetitive responses and
food intakes of individuals with no stomach were nearly identical to
those of control subjects, and studies of patients with balloons
inserted in their stomachs reveal the short-term effects of volume on
appetite were lost over time.
Dr. Mattes then turned to the question of whether energy density was a
reliable predictor of a food's dietary impact. He considered this from
four perspectives: dietary experience, satiation mechanism, energy
metabolism, and dietary compliance.
To illustrate common dietary experience regarding energy density and
dietary impact, Dr. Mattes presented studies that compared intake
following a test meal of liquid versus solid foods. Dr. Mattes
asserted that beverages should be included in such analyses because
they now contribute over 25 percent of energy intake, including in the
form of liquid meal replacements. A meta-analysis of 42 similar
studies found that while semi-solid or solid foods were associated
with reduced intake at a subsequent meal or over the day, there was no
dietary compensation following the intake of clear energy-yielding
fluids. A four-month intervention trial that compared intake following
daily consumption of a 450-calorie solid carbohydrate or liquid found
precise dietary compensation and not significant change of body weight
following the solid food while there was no compensation for the
energy load and an increase of body weight when the calories were
consumed as a liquid. A database analysis, which compared meals with
various types of beverages (diet and regular sodas, coffee, alcohol,
milk, and juice) to meals without beverages, found that increased
caloric intake was primarily due to the contribution of the beverages.
Dr. Mattes showed a table summarizing 16 preload studies involving a
manipulation of protein content that demonstrated consistent effects
on appetite and food intake when the protein was in a solid food
whereas there was little effect when the protein was consumed as a
liquid. He noted that while there was compelling evidence that protein
produced greater satiety than other macronutrients its satiating power
was greatly diminished when consumed in liquid form. Long-term data
showed that daily caloric intake among adolescents increased in
proportion to soft drink consumption, and David Ludwig's data on
children showed that for every serving of beverage included in the
diet, there was a quarter-unit increase in BMI within the study
population. Dr. Mattes concluded that, in contrast to the prediction
about energy density and energy intake, a very energy dilute food,
such as a beverage, could be problematic in terms of maintaining
Dr. Mattes then reviewed research findings on nuts to address the
dietary impact of energy-dense foods. He cited numerous
epidemiological and clinical studies that found an inverse association
between frequency of nut consumption and BMI. Dr. Mattes concluded
that high energy-dense foods do not necessarily pose a threat to
energy balance. Based on several lines of evidence, Dr. Mattes
suggested that this could be due to the strong satiety value of
selected energy dense foods, the possibility that they may promote
elevated energy expenditure, or differences in the absorption
efficiency of their macronutrients. He noted that the Atkins diet,
which is extremely energy-dense, is very effective for promoting
weight loss in the short term, though he acknowledged concerns about
its long-term safety and efficacy.
Turning to a discussion of energy density and satiety, Dr. Mattes
stated that numerous published reports suggest that people tended to
eat a consistent amount of food, by weight. This led to the notion
that energy-dilute foods would be beneficial in curbing appetite and
controlling intake. Development of the Volumetric Diet stemmed from
this work. However, Dr. Mattes noted that the while subjects on a
volumetric diet lose weight and are not more hungry than self-reports
at baseline, compliance with the diet was poor. This was because
individuals indicated they were not willing to spend more for fresh
fruits and vegetables and did not have time to shop more often for
fresh produce, prepare such items or clean-up after preparing them.
The Volumetric Diet could not be considered effective if people would
not follow it.
Dr. Mattes also noted that positive energy balance, as the result of
an energy-dense diet, was inconsistent with data that intake increases
with portion size. Presumably energy dense foods promote high levels
of energy intake because the portion size is not reduced to offset the
high energy density (i.e., a set weight is consumed) whereas the
concern with increasing portion sizes is that intake is proportional
to portion size (i.e., a variable weight is consumed). He suggested
that these diametrically opposed findings could indicate that food
intake was regulated by cultural definitions of appropriate portion
size and not by a physiological mechanism. To test that hypothesis,
Dr. Mattes conducted a study that compared intake of unnecessary small
versus customary portion sizes of low-energy dense and high-energy
dense foods. This study found that subjects still consumed a constant
amount of food, by weight, so that overall caloric intake varied with
the energy density of the food. However, it is possible the
experimental manipulation of presenting a novel portion size to
disrupt culturally defined standards may not have been effective. Dr.
Mattes stated that while it appeared that energy density had a greater
impact on regulating intake than volume, he did not consider either to
be an appropriate standard for dietary guidance.
Addressing the issue of energy metabolism, Dr. Mattes refuted the
general assumption that all calories are used comparably. He presented
data from a review paper showing that protein had a higher thermogenic
property and hence a lower energy contribution than carbohydrate or
fat. Dr. Mattes also noted that fats of different saturation were
oxidized differentially. He presented data showing that when
monounsaturated fats were substituted for saturated fats without
changing caloric content, there was a significant reduction in body
weight and body fat, presumably due to the differential oxidation of
the different fatty acids. He noted that it would be important to
determine whether these findings were true over time.
The final issue addressed by Dr. Mattes was the relation between
energy density and dietary compliance. Data from one study showed that
a moderate fat diet (hence, energy dense) was associated with a much
higher retention of participants as well as unexpected improvements in
the quality of the diet, because people were willing to eat more
vegetables if they could also have some fat, such as salad dressing. A
study from the current issue of the American Journal of Clinical
Nutrition found that while energy density was a significant predictor
of energy intake for a meal or over the course of a day, it was not a
good predictor of intake over time. Energy density was not a better
predictor of energy intake than other factors, such as meal
patterning, how many people the individuals actually ate with,
palatability, hunger or variety. Dr. Mattes noted that in the real
world, people can compensate for the effects of a particular food or
meal by balancing their intake of high- and low-energy dense foods.
Dr. Mattes stressed that cognition was an important factor in satiety
and energy intake. He cited a study in which both lean and obese
people reported more hunger when they thought they had eaten a
low-calorie food, regardless of the actual calorie content of that
food. In another study, subjects reported a greater level of satiety
for warm apple juice served in a bowl as "apple soup" than for the
same juice served cold in a glass.
Dr. Mattes concluded his presentation by stating that energy density
was not a reliable predictor of appetite response or energy balance.
He noted that energy-dense foods may contribute to nutritional quality
and they may play an important role in dietary compliance.
Dr. King thanked the speakers for their presentations and opened
the floor for discussion.
Dr. Pi-Sunyer asked Dr. Rolls to comment on sugar as an
energy-dense food. Dr. Rolls stated that there were a number of good
reviews regarding the contribution of different components of food to
energy density. She chose to focus on beverages, since Dr. Mattes had
addressed them in his presentation and stated that it was sensible to
approach the issue of beverages from a scientific basis. Dr. Rolls
noted that she was reviewing the CSFII adult data and looking at
different ways of calculating energy density to determine the relative
contribution of food alone, food plus different types of beverages,
and food and all beverages to overall energy intake.
Based on her analysis, Dr. Rolls felt that the best way to
determine the energy density of the diet and its impact on BMI was to
look at food alone. Examination of intra-individual and
inter-individual coefficients of variation indicate that energy
density values calculated based on food and all beverages as well as
food and caloric beverages exhibit little variability. With little
variability in estimates of energy density based on these calculation
methods, it will difficult to find significant associations with other
Dr. King asked whether there were any standards to define low
versus high energy density. Dr. Rolls replied that since data on
energy density was not available when she began work on her first
book, she divided foods into four categories. As it turned out, those
categories made sense when looking at large datasets, and other
researchers had continued to use them. She acknowledged that the
categories could be revisited.
Dr. Clydesdale asked Dr. Rolls to clarify whether she was stating
that solid foods alone provided the best data for correlating energy
density with BMI. She replied that the study was examining variance of
energy density calculation methods based on the inclusion or exclusion
of different types of beverages, by gender. She noted that including
beverages had a disproportionate effect on energy density. Energy
density calculated based on food alone provided data with considerably
more variance than data based on food and all beverages as well as
food and caloric beverages. A preliminary analysis indicated that the
energy density of total diets declined with increasing age and was
higher in men than in women. Dr. Rolls stated that a report on
methodological issues pertaining to the calculation of energy density
in free-living individuals would soon be submitted for CDC clearance.
Dr. Rolls noted that many of the studies she reviewed did not
include a definition of energy density or a description of what they
counted as "food." She stated that she classified soup as a food
and considered juice, milk, and alcohol as beverages. The all-caloric
beverages group included soft drinks and similar liquids.
Dr. Lupton asked Dr. Mattes if his statement that beverages
accounted for 25% of calories included alcohol. He replied that the
percentage would be higher if alcohol or newer types of caloric
beverages were included. He noted that the impact of alcohol on energy
intake was a complex issue, because moderate drinkers did not
generally weigh more than non-drinkers.
In response to another question from Dr. Lupton, Dr. Mattes stated
that he did not know of any metabolic issues related to how
carbohydrate calories are dissipated that would explain why different
types of carbohydrates did not appear to have an impact on BMI, as
with proteins and fats, despite their clear association with increased
Dr. King asked Dr. Mattes to comment on the effect of ghrelin on
appetite. Dr. Mattes replied that attempts to identify a single gut
hormone that reliably impacts hunger in humans have been unsuccessful
to date because the mechanism was complex. Dr. Rolls agreed and stated
that this complexity was why intake could be influenced by so many
different factors, including volume, portion size, and palatability.
She reiterated the consistent finding across many studies that people
tend to eat a consistent amount of food.
Dr. Appel noted that the PREMIER study had shown that fruits and
vegetables led to only slight reduction in weight compared to other
weight loss interventions. From a review of the literature, it can be
surmised that, while the data are not definitive, there is an
indication that higher consumption of low-density foods is associated
with persistent weight loss, and vice versa. Dr. Rolls stated that she
had not dismissed any studies, but that data on fruit and vegetable
consumption and body weight could be difficult to interpret because
studies did not always indicate the kinds of fruits and vegetables,
when they were consumed, and how they were prepared. Often juice was
considered along with whole fruit or vegetables. She noted the need
for more systematic data on fruits and vegetables and energy density.
Dr Kris-Etherton noted that while Dr. Rolls had recommended a
low-fat, low energy-dense diet, Dr. Mattes had shown that participants
on a moderate fat diet tended to consume more fruits and vegetables,
which could lower the overall energy density of the diet. Dr. Rolls
replied that the McManus study cited by Dr. Mattes was the only study
that was commonly used to argue for a higher-fat diet for weight
management. She agreed that the greater fruit and vegetable
consumption was probably responsible for weight loss on this diet, but
she noted that the number of subjects retained throughout the study
was low. She stressed the importance of informing people that portions
would be smaller on higher-fat diets unless they bulk up the diet with
low-energy dense foods and recommended a total fat intake of 20 to 30
percent of calories, possibly as high as 35 percent. Dr. Mattes agreed
that this would be a reasonable range, but he stated that it was more
important to focus on the overall diet than on specific nutrients,
because lifestyles and metabolisms vary. He also noted that a study
with children had shown no relationship between fruit and vegetable
intake and BMI.
Dr. Kris-Etherton asked if the speakers could suggest how to
implement advice to increase intake of fruits and vegetables or
decrease the energy density of foods. Dr. Rolls noted that there were
no differences in attrition rates in her current study between the
low-energy dense group and the reduced-fat group, and that researchers
were able to reduce the energy density of mixed dishes by a third
without affecting palatability. She stated that small changes that
allowed people to eat modified versions of their favorite foods were
the easiest to sustain. She suggested that the restaurant and the food
industries could help by making low energy-dense foods more
affordable, attractive, and available so that it would be easier to
incorporate them into the diet.
Dr. Pi-Sunyer asked Dr. Rolls to comment on the role of fruits and
vegetables as a vehicle for added fats, such as salad dressings. She
reiterated the importance of increasing the availability of lower-fat
options and noted that participants in her studies rated low-fat
salads similar in palatability to more energy-dense dishes.
Dr. Caballero noted the need to consider the impact of the
environment in which people choose foods in order to understand
whether the results of a controlled study could be sustained over
time. Dr. Rolls stated that the objective of her ongoing
methodological study was to establish standard definitions for energy
density so that large datasets could be analyzed to determine the
types of food people were choosing and how it affected their body
weight. She noted that energy density had been overlooked until
recently and that research was just beginning in this area.
Dr. Nicklas noted that some foods that were moderately energy-dense
were very nutrient dense and asked if there were any studies that
looked at levels of energy density and their impact on dietary quality
or adequacy. Dr. Mattes agreed that many energy-dense foods, such as
nuts and cheese, were important sources of nutrients and expressed
concern that the focus on energy density would lead to foods being
identified as "good" or "bad" foods. Dr. Rolls stated that energy
density should be used as a guide for determining appropriate portion
Referring to Dr. Mattes' remarks regarding metabolism and energy
density, Dr. Go asked if physical activity would affect metabolism and
intake. Dr. Mattes stated that the literature showed that people who
exercised more had better appetite control and that positive messages
regarding activity were very important.
Dr. Weaver asked Dr. Mattes whether the fact that people did not
compensate for calories consumed in beverages was because the
physiological need for hydration was stronger than the mechanism for
appetite control. Dr. Mattes replied that, from an evolutionary
perspective, caloric beverages were a recent development and that the
means by which those calories escaped satiety mechanisms has not been
Dr. Camargo suggested a study in which one group of children would
be encouraged to drink water with meals, while another group would be
encouraged to drink soft drinks and asked the speakers to comment on
the potential long-term effect of the soft drinks on BMI. Dr. Mattes
stated that a study he conducted found that subjects who added soft
drinks to their diets gained weight. He reiterated his earlier
statement that fluid calories add to the diet rather than reducing
other calories. In his opinion, increased intake of fluid calories
would lead to positive energy balance and weight gain. He was less
convinced that consuming water with a meal would lower the caloric
intake of that meal. Dr. Rolls stated that people do not eat less when
they drink water with a meal, but that studies with various caloric
beverages indicate that calories from beverages consumed at a meal are
not compensated for and add calories to the meal. She noted that the
literature was complex, especially regarding the distinction between
liquid and solid foods.
Dr. Lupton asked about the potential impact on energy intake of
drinking two glasses of wine per day. Dr. Mattes stated that while the
wine would lead to a higher caloric intake, it would not necessarily
result in weight gain. Dr. Rolls agreed, based on her reading of the
epidemiological studies. Dr. Camargo noted that some older studies
found moderate intake of alcohol was associated with weight loss. Dr.
Rolls commented that there was little distinction in the literature
between types of alcohol or patterns of foods consumed with alcohol.
She cited a need for better studies.
Dr. Weaver agreed that there was a need to determine the impact of
various types of beverages, in light of proposed conclusive statements
regarding consumption of dairy products and alcohol. She asked whether
there was evidence that other beverages, such as juices or soft
drinks, were correlated with increasing weight. Dr. Mattes replied
that one study suggested every soft drink serving was associated with
the equivalent of a quarter-unit increase in BMI. Dr. Nicklas noted
that while other studies had shown a relationship between sweetened
beverages and weight gain, this explained only three percent of the
variance in overweight status.
Dr. Bronner asked whether the speakers could provide any advice for
people in environments with a high prevalence of energy-dense foods,
such as inner cities. Dr. Rolls recommended avoiding "value meals" and
increasing consumption of fresh fruit and vegetables. She reiterated
the need for education and the importance of making high quality
fruits and vegetables more affordable and available. Dr. Mattes agreed
and stated that the food supply should be adjusted to fit the
lifestyle of the population, not vice versa.
Dr. Clydesdale asked about how to address consumers' avoidance of
processed or frozen foods that could potentially provide better diets.
Dr. Rolls replied that studies had shown that when some people were
told that a food was healthier or more nutritious, they liked it less.
She agreed that attitudes toward technology further complicated the
issue. Dr. Mattes noted that while consumers complain about processed
foods, they expect them to be available because they fit their
lifestyle. He stressed that the food industry has a role to play and
should work with consumers to address the problem.
Dr. King asked whether fiber might account for differences in
satiety in the studies cited by the two speakers. Dr. Rolls replied
that there was good evidence that fiber affects satiety, but that
energy density and protein also played a role. Dr. Mattes stated that
while fiber was a factor in satiety, its contribution is likely
over-estimated. He expressed concern that clinical studies did not
reflect how people normally consume fiber. Dr. Rolls added that
choosing low-energy dense, high-fiber foods was a better approach to
satiety than using the glycemic index.
Dr. King thanked the speakers for their contributions and adjourned
the meeting for a short break.
Welcoming Remarks from Dr. Beato
Dr. King announced that Dr. Beato would be unable to attend the
meeting and that she had asked her colleague, Ms. Carter Blakey, to
deliver her remarks to the Committee.
Ms. Blakey expressed Dr. Beato's sincere regrets and thanked the
Committee on Dr. Beato's behalf for their hard work and for
volunteering their time to develop dietary guidelines for the American
people. She reminded the members that this was a Federal Advisory
Committee meeting and, as such, it operates under the Federal Advisory
Committee Act (FACA). She noted that responsibility for chartering the
Committee rotated between HHS and USDA. Any questions for the
Committee must be referred to the Designated Federal Officer, Ms.
Kathryn McMurry at HHS.
She reminded the Committee and observers that written comments
about the Dietary Guidelines would be accepted throughout the
public comment process, and she thanked those who had already
submitted their comments. She reminded observers that any comments
must be addressed to the Committee as a whole and submitted through
the staff so that all Committee members would have access to the same
information. Observers were not to approach Committee members to
discuss the Dietary Guidelines.
Dr. Beato also reminded Committee members that their charge was to
independently review the scientific evidence and make recommendations
about what constitutes a healthy diet that would best help Americans
promote their health and reduce their risk of chronic diseases. She
noted that their conclusions might be very different from current
eating patterns, but that they were to recommend what they felt was
the most health-promoting diet.
She reminded the Committee that the Dietary Guidelines are
the foundation for government nutrition policy and that many education
initiatives and activities were based on this guidance. She urged the
Committee to aim high and provide the best science-based advice that
would enable the HHS and USDA to make any necessary changes to the
nation's eating environment and food supply and to develop educational
messages that would help Americans make healthy choices. She
reiterated her appreciation for the Committee's hard work and stated
that the departments looked forward to the outcome of their
Dr. King thanked Ms. Blakey for delivering Dr. Beato's comments and
expressed the Committee's appreciation of the support that HHS and
USDA had provided the Committee in carrying out its task.
Presentation and Discussion: Physical Activity
H.W. Kohl, III
Dr. King introduced Dr. Harold W. Kohl, III, Lead Epidemiologist
and Team Leader of the Physical Activity and Epidemiology Surveillance
Team, Division of Nutrition and Physical Activity, CDC. She noted that
Dr. Kohl had worked in the field of physical activity and health since
1984, including research, developing and evaluating intervention
programs for adults and children, and developing and advising on
Dr. Kohl stated that the objectives of his presentation were to
review CDC activities in the area of physical activity recommendations
and to provide answers to five questions posed by the Committee
regarding the physical activity recommendations and their relation to
health and health outcomes.
Dr. Kohl noted that CDC had worked extensively to develop physical
activity recommendations for public health. Recent activity included
an expert panel on youth physical activity recommendation (convened,
with the assistance of CDC, in January 2004); revision of the 1995
CDC/American College of Sports Medicine (ACSM) Recommendations for
Physical Activity and Public Health; and development of physical
activity recommendations for older adults, which was currently
underway. Dr. Kohl stated that the youth activity recommendations and
revised CDC/ACSM recommendations had been drafted and that he could
share those recommendations with the Committee.
The primary objective of the expert panel on youth recommendations
was to develop evidence-based physical activity recommendations for
healthy school-aged children and adolescents. The panel's goal was to
develop evidence-based recommendations that could be uniformly adopted
by public health and clinical agencies and organizations. Dr. Kohl
stated that it was extremely important to develop uniform guidelines
to replace the disparate and often diverging recommendations in this
The panel reviewed the most current data available in a broad range
of topics related to health and health outcomes for children and
adolescents, including academic performance, injury, and overweight
and obesity. Based on that evidence, the panel recommended that
children and adolescents of school age should participate in 60
minutes or more of moderate to vigorous physical activity daily. The
physical activity should consist of a variety of enjoyable age- and
developmentally appropriate activities.
Dr. Kohl then addressed the physical activity recommendations that
were being developed for older adults (age 60 and above). The primary
objective of these recommendations would be to reduce sedentary
living. They would be based on the physical activity recommendations
for adults, with several modifications. First, intensity would be
defined relative to the individual's fitness level. Second, balance
exercises would be recommended for individuals at increased risk of
falls, and there would be an explicit flexibility recommendation.
Third, the recommendations would emphasize moderate intensity physical
activity and participating in all recommended types of activity
(endurance, strength, balance, and flexibility). They would stress a
gradual approach to increasing physical activity for those who are
inactive, with an explicit goal of reducing sedentary living. Finally,
the recommendations would incorporate risk-management strategies for
injury prevention. Dr. Kohl expected that 30 to 60 minutes of
moderate-intensity physical activity would be recommended as a
Dr. Kohl noted that the most recent U.S. public health
recommendations, issued in 1995 by the CDC/ACSM, were that every adult
should accumulate at least 30 minutes of moderate-to-vigorous physical
activity on most, and preferably all, days of the week. This guidance
was consistent with the Surgeon General's report of 1996 as well as
recommendations developed by the American Heart Association, the World
Health Organization, and others.
Dr. Kohl stated that developing physical activity recommendations
was a complex issue, because the relationship between physical
activity and risk of disease differed by disease. He presented a chart
showing that while risk for most diseases decreased with moderate
physical activity, high levels of activity may be associated with
increased risk for musculoskeletal injury, osteoarthritis, and stroke.
Dr. Kohl highlighted the key points from the recent revision of the
1995 CDC/ACSM recommendations. He noted that the revised
recommendations would reiterate the public health importance and low
prevalence of physical activity and would clarify and reaffirm that 30
minutes of physical activity per day, five days per week, was a
minimum, not maximum, recommendation. They would clarify and reaffirm
the dose-response relationship, emphasizing that "more is better," and
they would specifically address the role of physical activity in
weight maintenance and prevention of weight gain.
Following this overview, Dr. Kohl reviewed the draft text of the
- "To promote and maintain good health, all U.S. adults should
accumulate at least 30 minutes of moderate-intensity physical activity
on five or more days each week, or vigorous-intensity physical
activity amounting to at least 20 minutes on three or more days each
week." Dr. Kohl noted that these would be base, or minimal, levels of
- "In addition to routine activities of daily living, physical activity
of moderate intensity (equivalent to a brisk walk) can be accumulated
in 8-10 minute periods of time toward the 30-minute goal. Vigorous
activity (equivalent to a jog) is also recommended." Dr. Kohl noted
that this section clarified key terms, such as "moderate" and
- "In addition to physical activity on 5 or more days each week, muscle
strengthening and endurance exercises (such as lifting weights or
similar resistance exercises) should be performed at least two days
each week in order to promote and maintain muscular and skeletal
health and function." This provision would affirm the importance of
muscular strength and endurance exercises in addition to aerobic
- "Participation in physical activity above the minimum recommendation
provides additional health benefits and results in higher levels of
physical fitness. Adults who wish to further reduce their risk for
chronic conditions such as cardiovascular disease, obesity, type 2
diabetes mellitus, some cancers, osteoporosis, and depression should
exceed the minimum recommendation for physical activity." Dr. Kohl
noted that this provision clarified and affirmed the dose-response
- "Because current scientific evidence indicates that risk of
chronic conditions is incrementally lower with more physical
activity, physical activity above the minimum recommendation is
likely to result in additional health benefits. For example to help
prevent unhealthy weight gain, some adults may need to participate
in physical activity for more than 30 minutes each day to a point
that is individually effective, taking into account diet and other
factors affecting body weight."
Dr. Kohl then turned his attention to the five questions that the
Committee had asked him to address:
Question 1: Is there a level of habitual physical activity that
can be recommended for the prevention of weight gain in persons with
normal BMI? Many people may require more than 30 minutes per day to
prevent weight gain how much more? Does this differ by age,
gender, race/ethnicity, and pregnancy/lactation? Does this differ
depending on whether the person is normal weight, overweight or obese?
Dr. Kohl stated that the level of physical activity (energy
expenditure) that would help prevent weight gain was that which was
required to perfectly balance energy intake. It would include
consideration of individual factors, such as body mass, resting
metabolism, and genetic variation. He noted that the Institute of
Medicine (IOM) had estimated that 60 minutes of moderate-intensity
physical activity, seven days per week would be necessary to prevent
weight gain, based on the findings of a doubly labeled water study
with weight-stable people. However, he also noted that there was no
outcome data specifically related to a level of physical activity that
might prevent weight gain. Moreover, some behavioral experts had
stated that 60 minutes of activity, seven days per week would be
ineffective as a public health recommendation and could result in
injuries for some individuals.
Dr. Kohl stated that the Committee should consider what
recommendations would be effective, in terms of both communication and
agreement. He noted that while surveillance data showed that the
prevalence of normal-weight individuals had decreased since 1988, the
prevalence of inactivity had actually declined during the same period.
This would suggest that the growing rates of obesity were not due to
inactivity. Dr. Kohl proposed that 30 to 60 minutes of moderate
physical activity on most days, or a roughly equivalent amount of
vigorous physical activity, would assist in providing the caloric
balance required to maintain body weight.
Question 2: How much physical activity is required to avoid weight
gain in formerly obese persons?
Dr. Kohl replied that there were several sources of data pertaining to
this question. Data from the National Weight Control Registry
indicated that the most effective dose would be one hour or more. A
clinical trial found that 75 to 90 minutes of activity was required to
sustain weight loss over time. Dr. Kohl suggested that for some
people, the amount of activity to prevent weight regain would probably
be 60 to 90 minutes of moderate physical activity, or an equivalent
amount of vigorous activity.
Question 3: How much and what types of physical activity are
recommended for optimal bone health? How does this differ by age and
Dr. Kohl noted that the key indicators of osteoporosis were changes in
bone mineral density. He stated that there was little evidence that
physical activity protects against the development of osteoarthritis
and no evidence that light or moderate physical activity increases
risk of osteoarthritis. While there was fairly convincing data that
large amounts of heavy, prolonged physical activity, such as
occupational exposure over many years, could increase the risk of
osteoarthritis in the knee and hip, clinical data indicated that
moderate physical activity was an effective treatment for
osteoarthritis of the knee. Dr. Kohl noted that similar data was not
available regarding osteoarthritis of the hip.
Dr. Kohl stated that osteogenesis appeared to respond to loading from
either gravity (impact, or weight bearing exercise) or muscular
contraction. He noted that peak bone mass was reached early in life
and could be increased with physical activity during that period,
though there were gender and age differences. Dr. Kohl stated that
there was strong evidence from randomized clinical trials that
physical activity in pre-menopausal women could maintain or increase
bone mass, and other studies found that physical activity in
post-menopausal women could slow the rate of bone loss in some cases.
Dr. Kohl noted that while the dose-response for osteogenesis was
unknown, light-to-moderate activity appeared to be insufficient; he
suggested brisk walking as a minimum.
Dr. Kohl emphasized that the effects of muscle strengthening and
impact activities appeared to be site-specific. For example, walking
would increase bone strength of the lower back, while upper body
exercises would strengthen bones in the shoulder and forearm. He noted
that the literature in this area was complex because exposures varied
among studies, making it difficult to compare data.
Question 4: What are the health benefits, if any, of being physically
active only 30 minutes each day?
Dr. Kohl noted that it was difficult to answer this question because
the data from existing studies was often presented in terms of caloric
expenditure or quantiles rather than specific amounts of time.
However, there was overwhelming evidence from both clinical trials and
epidemiological studies to support the 30-minute recommendation in the
Surgeon General's report. He cited a long-term epidemiological study
of Harvard male alumni, which showed a 20 percent reduction in the
risk of all-cause mortality corresponding to expending 1,000 to 2,000
calories per week in leisure time physical activity. He presented data
from other studies showing that moderate physical activity equivalent
to 30 minutes per day, most days of the week, was associated with
reduced risk of Type 2 diabetes incidence and cardiovascular disease
death. Dr. Kohl noted that new data regarding dose-response
relationships had become available in recent years as clinical trials
became more sophisticated, which was one factor in the CDC's decision
to update its recommendations.
Question 5: How do the new CDC/ACSM and youth
recommendations compare/differ from the 2000 Dietary Guidelines for
Americans? What is the rationale for any differences?
Dr. Kohl stated that, while the youth recommendations were
consistent with the existing guideline on physical activity, they
would enhance the Committee's deliberations because they were based on
a thorough review of the existing recommendations and the scientific
evidence. Moreover, the youth recommendations were consistent with the
Committee's emphasis on consistency because they were designed to
harmonize multiple recommendations so that public health and clinical
groups could speak with one voice. Dr. Kohl also noted that the
document included specific examples and strategies for implementing
The revised CDC/ACSM recommendations would place a greater emphasis
on the dose- response relation between physical activity and health
and would stress that 30 minutes of activity per day was a minimal
Dr. Kohl summarized his presentation by reiterating the following
- Moderate-to-vigorous physical activity was associated with many
health outcomes and was causal in several.
- For adults, 30 minutes of physical activity per day, five days
per week, was as a necessary and sufficient minimum, not maximum,
level to promote and maintain health. Higher levels of physical
activity were associated with improved health outcomes. For
individual health outcomes, including weight control, some people
may require more physical activity than the minimum recommendation.
- Children and adolescents of school age should participate in 60
minutes or more of moderate-to-vigorous physical activity daily.
In Dr. Kohl's view, a single guideline related to physical activity
would be inadequate, given the complexity of the science related to
physical activity and health outcomes. He noted that the CDC would
recommend a separate Guidelines process pertaining to physical
activity and health.
In conclusion, Dr. Kohl stated that a healthy United States adult
population would be characterized by a variety of physical activity
levels, with all adults participating in at least 30 minutes per day
of moderate-intensity physical activity.
Dr. King thanked Dr. Kohl for his presentation and opened the floor
Dr. Pate noted that the new CDC/ACSM recommendation appeared to
reaffirm the 30-minute guideline, while stressing the value of more
and emphasizing the dose-response relationship, whereas the IOM
recommended 60 minutes of daily activity. He asked whether the
Committee would be consistent with the updated recommendation from
CDC/ACSM if it were to recommend a range of 30 to 60 minutes of daily
physical activity. Dr Kohl replied that such an approach would be a
useful strategy to harmonize the CDC/ACSM recommendation with the
findings of the IOM and other groups. He noted that the data would
support such a range and reiterated the importance of striving for
consistency, where possible.
Dr. Pi-Sunyer expressed concern that it would be inconsistent and
confusing to state that 30 minutes of activity five days a week would
be sufficient, while also stating that higher levels could lead to
better health. Dr. Kohl replied that the CDC/ACSM panel found that the
most consistent threshold in existing literature was approximately 30
minutes a day of physical activity. However, the panel also believed
that it was increasingly important to convey a dose-response message,
which had not been emphasized in the original recommendations. Dr.
Kohl stated that he would be satisfied if the 35 percent of the
population that was currently inactive were able to achieve the
Dr. Caballero agreed with Dr. Pi-Sunyer that there was a conflict
between the 30-minute recommendation and the dose-response
relationship, but he could accept 30 minutes as a target for the next
five or ten years. Referring to the correlations that Dr. Kohl had
presented between physical activity and various health risks, Dr.
Caballero stated that obesity should not be grouped with other chronic
conditions. He noted that dose-response conclusions regarding levels
of physical activity required to reduce risk of chronic disease were
based on survey data from epidemiological studies, while conclusions
regarding the energy balance necessary to address obesity were based
on experimental data. Dr. Caballero also described the methodology of
the doubly labeled water study that served as the basis for the IOM
recommendation on physical activity.
Dr. Pate noted that it was challenging to communicate physical
activity recommendations without confusing the public and asked if CDC
had any experts who could provide guidance in that area. Dr. Kohl
replied that one of the major differences between the recommendations
issued in 1995 and the updated version was the involvement of a
communications team that worked on ways to harmonize and communicate
the recommendations. The communications specialists conducted focus
groups with consumers to gather data that would help shape the
messages, as well as focus groups with opinion leaders in the popular
media regarding ways to package and disseminate those messages.
Dr. Camargo stated that he would not support the creation of
separate physical activity guidelines. In his view, it was important
to integrate physical activity and diet in order to harmonize
recommendations and emphasize the concept of energy balance. He asked
Dr. Kohl for his opinion of pedometers as a means of estimating daily
caloric expenditure and motivating people to exercise. Dr. Kohl
replied that pedometers were useful behavioral tools because they were
inexpensive and unobtrusive. He noted that research was needed into
the role of pedometers in helping people meet the physical activity
recommendations and mentioned that CDC had launched a project to
determine how many steps were required to meet the minimum recommended
level of physical activity.
Dr. Appel asked how focus groups had responded to the IOM
recommendation of 60 minutes of activity. Dr. Kohl stated that the
focus groups did not include questions regarding specific levels of
activity, but they did ask about participants' understanding of the
dose-response message. Focus group participants clearly understood the
"More is better" message, and those who were physically active felt
that 30 minutes was not enough activity. Dr. Appel noted that in a
focus group he had conducted, some people perceived shopping to be
physical activity. He asked whether that was an isolated finding or if
it reflected problems in communicating with people at the lower end of
the physical activity spectrum. Dr. Kohl replied that people tended to
underestimate the intensity and duration of activity that was required
to meet the recommendations. He acknowledged the need to more clearly
define terms such as "moderate intensity" and to clarify what would
count as ten minutes of physical activity.
Dr. Pi-Sunyer asked Dr. Kohl to explain why he stated that
recommending 60 minutes of physical activity for older adults could be
confusing or dangerous. He noted that Dr. Kohl had stated there was no
evidence that exercise could lead to osteoarthritis, and he cited
studies that showed numerous benefits of exercise for older adults. He
also noted that older adults have the most time available for physical
activity. Dr. Kohl replied that, while there was no data, there was a
concern that unsupervised physical activity could lead to increased
risk of injury among older adults would could be at risk for falls. He
acknowledged the importance of physical activity among older adults
and noted that the oldest age group in the BRFSS data had shown the
greatest decline in inactivity over the past 17 years. While he did
not intend to single out any groups, he stated that it was important
to acknowledge that physical activity could pose a risk in some cases
and that the upper limit for physical activity may be different for
Dr. King addressed the issue of the recommended amount of activity
for children. She noted that California schools were mandated to
provide 100 minutes of physical activity per week, which was generally
met through physical education and recess. She expressed concern that
children in unsafe neighborhoods might not have opportunities for
physical activity outside of school and asked Dr. Kohl to clarify the
rationale for the recommendation. Dr. Kohl first clarified that the
youth recommendations were developed by an independent expert panel
and not by the CDC. He stated that the expert panel had considered the
fact that activity levels naturally decline with age and chose to set
the bar higher, with the goal of establishing healthy levels of
physical activity at an early age. The recommendations were designed
to take into account the intermittent nature of children's physical
activity. Dr. Kohl acknowledged that children would not be able to get
all of the activity they need at school and stressed the need for
environmental changes that would promote activity, such as walking to
Dr. Appel noted that the Dietary Guidelines would have a regulatory
impact in some areas, such as WIC and other federal nutrition
programs, and asked if adopting the 60-minute recommendation could
potentially lead to changes in the physical activity guidelines for
schools. Dr. Pate replied that there were numerous initiatives
underway to communicate the importance of this issue to policymakers
and institutions. He stated that the Committee's recommendations would
be influential, but they would have no legal impact.
Dr. Pate noted that physical activity affected many aspects of
health in addition to obesity and asked if Dr. Kohl could help the
Committee decide how inclusive its recommendations should be. Dr. Kohl
replied that focusing too closely on individual outcomes would limit
the literature that could be cited as a rationale for recommendations.
He noted that the scientific basis for specific benefits was less
solid and suggested that a global recommendation that could be
substantiated by heterogeneous studies would be more appropriate for
public health guidance.
Dr. Camargo noted that 30 minutes was a healthy amount of physical
activity, yet it represented less than two percent of a person's
available time. He suggested that it might be preferable to focus on
what types of activities people were engaged in the rest of the day.
Dr. Kohl replied that the literature had evolved from observational
studies of occupational exposure conducted in the 1950s and that data
was now available from clinical trials on the impact of accumulated
moderate activity, including some activities of daily living.
Dr. King thanked the speaker for his presentation and adjourned the
meeting for lunch.
Discussion of Conclusive Statements and Rationale
Dr. King reconvened the meeting and stated that the first part of
the afternoon would be devoted to discussing conclusive statements
drafted by three subcommittees: Carbohydrates, Fatty Acids, and
Macronutrients. She noted that each subcommittee would present its
conclusive statements, and that the Committee would discuss each
statement before moving to the next. She emphasized that the Committee
should evaluate each statement according to five criteria: strength of
the evidence; temporal characteristics; consistency of results;
specificity of results; and whether the statement was biologically
Dr. King then turned the floor over to Dr. Lupton to present the
conclusive statements of the Carbohydrates Subcommittee.
Conclusive Statements and Discussion
J. Lupton, Lead
Dr. Lupton stated that the Subcommittee members included Drs.
Clydesdale, Pate and Pi-Sunyer and acknowledged the USDA staff members
who had provided support to the Subcommittee. She noted that the
Subcommittee was moving from carbohydrate-based to food-based
recommendations. This entailed collaboration with other subcommittees
because some items that were originally "carbohydrate" issues were now
seen in a broader context. The issue of carbohydrate/fat/protein
ratios in the diet was now being addressed by the Macronutrient
Subcommittee, and the Fruits and Vegetables Subcommittee was reviewing
the role of fiber in those foods.
Dr. Lupton presented an overview of the status of the
Subcommittee's conclusive statements. She noted that the Subcommittee
had drafted a statement regarding dietary fiber and carbohydrates and
was in the process of drafting a statement regarding dietary fiber and
laxation, a statement on whole grains and their contribution to
health, and a statement on carbohydrates and diabetes. The
Subcommittee was also considering the new issue of "added sugars" as
discretionary calories, in collaboration with the Macronutrient
Subcommittee chaired by Dr. Caballero.
Dietary Fiber and Decreased Risk of Coronary Heart Disease
The Subcommittee had drafted the following conclusive statement:
"Diets rich in dietary fiber can reduce the risk of coronary heart
disease." The implications for the general population were that 14
grams of fiber per 1,000 calories should be consumed each day.
Dr. Lupton stated that this recommendation was based on a complete
review of the dietary fiber and carbohydrate literature in the IOM
Macronutrient report, updated by a review of any new literature that
had been published since that report was issued. The evidence
supporting the recommendation consisted of prospective epidemiological
studies, a large number of small clinical intervention trials with LDL
cholesterol or blood pressure as the endpoint, and cross-sectional
Dr. Lupton noted that the three large-scale epidemiological studies
reviewed by the Subcommittee (Health Professionals Follow Up Study,
Nurses' Health Study, and Finnish Men's Study) all showed a decrease
in relative risk of coronary heart disease for the highest versus the
lowest quintile of fiber intake. Subjects in the highest quintile of
these studies consumed an average of 14 grams of fiber per 1,000
calories, which the IOM established as the AI for dietary fiber.
Dr. Lupton presented a chart that illustrated the recommended
amount of fiber, based on calorie intake for each gender and for each
age group. She noted that fiber intake would be lower for women than
for men as well as for younger children.
Dr. Lupton pointed out that the Subcommittee had changed the draft
statement distributed to the Committee in the following ways: it added
the IOM report to the references; it deleted a phrase stating that
dietary fiber may lead to increased insulin sensitivity; it added
examples of high fiber foods; and it modified the table by adding
references, clearly delineating the end point of each study, and
noting the type(s) of fiber in the study, if specified in the
literature. Dr. Lupton then opened the floor for discussion.
Dr. Appel expressed concern that the data on fiber in the
epidemiological studies could be over reported because the
questionnaires had not been designed to study fiber, and he asked if
there was any data to validate the IOM's recommendation on fiber. Dr.
Lupton replied that all three studies had shown the same effect, but
she acknowledged that there was no validation of the specific amount
of fiber that was required for that effect.
Dr. Nicklas was concerned that most of the IOM recommendations had
been based on adult studies and that the proposed recommendations for
children were extrapolated from adult recommendations. She asked if
the Subcommittee's report would include a statement addressing fiber
in children. Dr. Lupton replied that the Subcommittee would include a
statement about the need to increase fiber intake for children
gradually over time, based on a review of the extensive literature
that was now available in that area.
Dr. Nicklas asked if the Subcommittee would address different types
of fiber in its recommendation. Dr. Lupton stated that the beneficial
effects in most studies were due to high-fiber foods rather than a
particular type of fiber. She noted that the report would discuss the
benefits of various types of fiber where possible, but the
recommendation was based on total fiber intake.
Dr. King asked how fiber would benefit children, who are not
generally at risk for coronary heart disease. Dr. Lupton stated that
adequate fiber intake in children had two potential benefits:
establishing healthy eating habits at a young age, and improved
Dr. Pate noted that the smooth dose-response relationship between
fiber and coronary heart disease provided no clear threshold and
stated that the Committee might confront this issue in other areas. He
asked whether the recommendation was based on a level that would
reduce risk, or a level that would minimize risk. Dr. Lupton replied
that the recommendation was based on fiber intake in the highest
quintile in the three epidemiological studies, which was associated
with a statistically significant reduction in the risk of coronary
heart disease. She acknowledged that it could be difficult to specify
a threshold in some cases, but she noted that while some studies had
shown a gradual reduction of risk as fiber intake increased, others
had shown no effect until a high level of fiber intake had been
Fiber and Laxation
Dr. Lupton stated that the Subcommittee was proposing a second
conclusive statement on the overall benefits of fiber because it did
not seem appropriate to include laxation in the same statement as
coronary heart disease. She noted that while the effect of fiber on
laxation was well documented, there was no quantitative data upon
which to base a recommendation for a specific amount of fiber. She
asked the Committee for advice as to what the statement should include
and the type of documentation that would be needed for the
recommendation to be scientifically valid.
Dr. Weaver noted that increased laxation could be due to physical
activity as well as fiber. Dr. Lupton replied that some studies had
found that increased physical activity was associated with greater
constipation, which was contrary to assumptions that fiber and
physical activity would both improve laxation and would therefore be
protective against colon cancer. She asked Dr. Pate to comment on this
issue. He stated that while he was not familiar with the literature on
physical activity and laxation, studies of physical activity and colon
cancer were compelling, though the underlying mechanism was not well
understood. Dr. Lupton noted that there was no evidence in the
literature to support a recommendation on dietary fiber and colon
Dr. King asked Dr. Lupton to clarify a point on her slide that
indicated that this statement would target pregnant women, the
elderly, and children. Dr. Lupton stated that while the statement
would not be directed only to these groups, they were highlighted
because they represented transition phases introducing different
levels of fiber intake.
Dr. Nicklas noted that absorption rates and laxation seemed to
increase from childhood to adulthood and then decline with age and
recognized that it could be challenging to draft a statement that
would address those variations. Dr. Lupton replied that the
Subcommittee had not intended to develop a recommendation based on
different age levels, but it seemed appropriate to include information
pertaining to pregnant women, the elderly, and children because
laxation had been identified as a concern for those groups.
Dr. Lupton asked the Committee if there was a need to develop a
consensus statement regarding any other effects of fiber.
Dr. Weaver stated that it was more important to focus on
implementing the IOM recommendations in the context of the whole diet,
combined with physical activity. She expressed concern that while
there was dose-response data regarding quantities of specific sources
of fibers, such as whole grains, there were no studies comparing the
benefits of whole grains versus fiber from other sources, such as
vegetables or legumes. Dr. Lupton agreed that this was a limitation
and that data regarding specific types of fiber was only available in
the literature on laxation. Dr. Appel questioned whether a second
conclusive statement would be justified without sufficient data.
Dr. King asked about the benefits of fiber for colon cancer. Dr.
Lupton replied that four large-scale studies had been conducted, but
none had shown a protective benefit of fiber. The Subcommittee decided
it would not be appropriate to base a recommendation on these studies.
Dr. Bronner asked what the recommendation would be for introducing
fiber to children. Dr. Lupton replied that the statement had not been
drafted, but it would probably recommend a gradual increase over time.
Dr. Lupton stated that the Subcommittee's conclusive statement on
this issue would probably state: "Diets rich in whole grains can
reduce the risk of coronary heart disease." The implication of this
statement for the general population would be that whole grains should
be substituted for refined grain foods wherever possible. The
Subcommittee was still considering whether there was sufficient
evidence to recommend a specific amount.
Dr. Lupton noted that this recommendation was supported by many
studies showing an inverse association between intake of whole grains
and total mortality as well as CVD-specific mortality. The
recommendation was also supported by the literature on fiber, since
whole grains were an important source of dietary fiber.
Dr. Lupton stated that the Subcommittee's statement would also
provide information on the benefits of whole grains, aside from fiber;
it would define whole grains and show how they differ from refined
grains, and it would define good sources of whole grains and provide
information on how to find them on food labels. She then opened the
floor for discussion.
Dr. Nicklas asked whether a product consisting of 51 percent whole
grains would be considered a whole grain product. Dr. Lupton clarified
that this percentage pertained to the requirements for the health
claim that is allowed for whole grain products.
Carbohydrates and Diabetes
Dr. Lupton noted that Dr. Pi-Sunyer was in the process of drafting
a conclusive statement to address this issue.
Added Sugars and Discretionary Calories
Dr. Lupton noted that the Macronutrient Subcommittee was reviewing
the issue of discretionary calories. The question of whether added
sugars would be treated as potential sources of discretionary calories
or as a separate issue was still unresolved. The Carbohydrates
Subcommittee recommended that information on added sugars be conveyed
in the discussion of discretionary calories.
Dr. Lupton reminded the Committee that "added sugars" were defined
as sugars and syrups that are added to foods during processing or
preparation. Lactose in milk or fructose in fruit would not count as
added sugars. Major sources of added sugars include soft drinks,
cakes, cookies, pies, fruit punch, dairy desserts, and candy. She
noted that added sugars supplied calories, but no other nutrients.
This raised concerns that added sugar could result in weight gain if
it caused caloric intake to exceed energy requirements, or it could
lead to micronutrient dilution if the calories replaced more
Dr. Lupton noted that the Subcommittee reviewed data pertaining to
three issues: added sugars and weight gain, added sugars and
micronutrient dilution, and levels of added sugar compatible with a
Dr. Lupton stated that most studies on added sugar and weight gain
found that added sugar intakes resulted in increased energy intakes.
However, many cross-sectional studies found a negative correlation
between added sugar intake and BMI. The only exception was a single
longitudinal study, which found a positive association between
sugar-sweetened beverages and BMI.
The evidence was more consistent regarding micronutrient dilution. Dr.
Lupton noted that every study showed a decreased intake of at least
one micronutrient with higher levels of added sugar intake. She
presented data from one study, which showed that groups with the
highest levels of added sugar intake had the lowest intake of several
Dr. Lupton noted that the IOM recommendation that intake of added
sugars should not exceed 25 percent of calories was based on an
analysis of NHANES III data. However, the NHANES data also showed that
the best level of added sugars for macronutrient intake was five to
ten percent, and not zero. This was consistent with a recent study,
which found that sweetened dairy products were associated with
increased calcium intake for children ages 4 to 8, and presweetened
breakfast cereals increased the likelihood of children and adolescents
meeting recommendations for calcium, folate, iron, dairy products. Dr.
Lupton stressed that these findings would suggest that a
recommendation to eliminate added sugars from the diet might not be
Addressing the issue of levels of added sugars compatible with a
healthy diet, Dr. Lupton noted that the USDA food guidance system
promoted a "total diet" concept by considering proportionality and
moderation by accounting for all foods consumed. The proposed food
intake patterns were designed to meet close to 100 percent of the
Dietary Reference Intake (DRI) values from foods that were typically
consumed by assigning specific numbers of servings to each of five
food groups. Dr. Lupton noted that the food patterns were based on
foods in their lowest fat form without added sugar.
Dr. Lupton explained that discretionary calories could be
determined by subtracting the calories required to meet 100 percent of
nutrient needs, or DRI, from the calories required to meet energy
needs, based on age, sex, and calorie level. She pointed out that
while added sugars or alcohol were potential sources of discretionary
calories, the extra calories could also be used for foods such as
hamburger, chicken with the skin on, or dairy products other than
At the Subcommittee's request, the USDA's Center for Nutrition
Policy and Promotion analyzed the food patterns to determine the
discretionary calories that would be available for females and males
of various age groups and activity levels. Not surprisingly, the
analysis found that more discretionary calories were available at
higher activity levels, and very few were available for low-active or
sedentary individuals. The maximum amount of discretionary calories
would range from six percent, based on a 1,200 to 1,600 calorie food
pattern, to 13 percent, based on a 3,400 calorie food pattern. Dr.
Lupton noted that these calculations supported a strong, positive
message that if you are more active, you have more discretionary
Dr. Lupton proposed three steps for putting the concept of
discretionary calories into use: calculating the maximum discretionary
calories for each gender and age level, recommending good food choices
for discretionary calories, and recommending increasing physical
activity to "buy" more discretionary calories.
Dr. Lupton suggested that foods and nutrients that could be
considered discretionary calories might include added sugars, fat
(both intrinsic and extrinsic), ethanol, and even starch. She noted
that starch was a significant portion of the typical diet, but it was
primarily a source of glucose.
In response to a question from Dr. King, Dr. Lupton clarified that
the calculations were based on food patterns with 30 percent of
calories from fat. She agreed that there could be more discretionary
calories if fat intake were lower.
Dr. Appel asked if the cross-sectional studies that showed no
association between added sugars and BMI were stratified by physical
activity. He noted that the only prospective study had shown the type
of association that was anticipated and stated that the
cross-sectional studies should not prevent the Subcommittee from
drawing inferences that otherwise make sense, based on calorie intake.
Dr. Lupton believed that most of the cross-sectional studies had been
stratified, but she would review them once again. Dr. Clydesdale
stated that it would be inadvisable to draw an inference either way,
without supportive evidence. Dr. Appel clarified that the issue was
the relative weakness of data from cross-sectional studies and asked
whether calories would be a valid surrogate for observational data.
Dr. Clydesdale noted that data on caloric intake that relied on recall
would also be questionable.
Dr. Camargo noted that reporting biases were common when overweight
subjects were asked what they eat, especially discretionary foods. He
stated that longitudinal studies were much more valid and that he knew
of at least one other prospective study that showed an increased
weight gain with added sugars. He agreed with Dr. Appel that the
Subcommittee should not be overly concerned about the three negative
Dr. Caballero expressed concern that the term "discretionary
calories" could be misleading because they were necessary to adjust
for the difference between the low-fat foods on which the food
patterns were based and the types of food that were typically
consumed. Dr. Lupton agreed that there was a need to be more
transparent about the foods that were included in the food patterns
and to clarify what was meant by "discretionary."
Dr. Pate stated that the Subcommittee's efforts to link
discretionary calories with activity level was an appropriate way to
integrate physical activity into dietary recommendations. He stressed
the need for internal consistency throughout the report as to how
physical activity levels were defined and quantified. Dr. Lupton
clarified that the USDA had used the physical activity levels
presented in the IOM report. She noted that some nutritional
requirements also increased with activity, making the issue of
discretionary calories more complex.
Dr. Caballero noted that the IOM report was the first to link
physical activity requirements to energy needs rather than body weight
or BMI. The proposed food patterns reflected the nutritional and
energy requirements for each activity level. As a person became more
active they would not simply have additional discretionary calories;
rather, they would move into the next category, which would provide
additional nutrients as well as extra calories.
Dr. Bronner noted that basing the food patterns on low-fat foods
could make it difficult for some people to follow the recommendations
unless they made adjustments for the types of foods they normally
consumed. Dr. Caballero reiterated his concern that the concept of
discretionary calories should be considered as an internal tool to
adjust the food patterns to the typical diet rather than a tool for
Dr. Camargo stated that the concept of discretionary calories would
help people make more sense out of their diet. He suggested that
redrawing the graphic based on typically consumed foods would clarify
the fact that most people would have few, if any, discretionary
calories. Dr. Appel asked if it would be feasible to revise the
graphic. Dr. Hentges replied that this could be done, but he noted
that low-fat foods were the basis of the traditional model, and that
this model could be modified to reflect individual choices. Dr. Weaver
stated that the Committee did not wish to challenge the food guide
patterns, but it would be useful to illustrate the impact of actual
Some Committee members suggested that "hidden calories" or
"choices" might be better terms than "discretionary calories." Dr. Go
proposed including an explicit message that more choices are available
if you increase your physical activity.
Dr. Nicklas suggested that the Subcommittee's report should include
references to two additional cross-sectional studies that showed no
association between added sugars and BMI. She supported the inclusion
of studies showing that added sugars in more nutrient dense foods
actually enhanced micronutrient intake. Dr. Nicklas then asked if Dr.
Lupton could clarify what she meant by "non-nutrient dense foods." Dr.
Lupton stated that while there was no consensus in the literature
regarding nutrient density, the Subcommittee had used this term to
refer to foods that were high in calories and low in nutrient value.
Dr. Lupton accepted Dr. Nicklas' suggestion that "less nutrient dense"
would be a more accurate term.
Dr. Appel stated that he could provide the Subcommittee with an
older prospective study showing that individuals who decreased their
consumption of sweets had greater weight loss.
Text of the 2000 Dietary Guidelines Concerning Carbohydrates
Dr. Lupton stated that the Subcommittee's conclusive statements
were pertinent to four of the 2000 Dietary Guidelines:
- Let the Pyramid guide your food choices
- Choose a variety of grains daily, especially whole grains
- Choose a variety of fruits and vegetables daily
- Choose beverages and foods to moderate your intake of sugars.
Dr. Lupton concluded her presentation by acknowledging the experts
who had advised the Subcommittee in several key areas, including Dr.
Ronald Krauss regarding fat/carbohydrate ratios, Drs. Joanne Slavin,
Michael McBurney, and Eric Rimm regarding whole grains, and Drs.
Rachel Johnson, Maureen Storey, and Richard Forshee regarding added
sugars. She also thanked the staff at the federal agencies for their
assistance with definitions of whole grains and added sugars and with
regulations concerning health claims, standards of identity,
fortification, and enrichment.
Dr. King thanked Dr. Lupton for her comprehensive presentation. She
stressed that the Subcommittee should continue to work on conclusive
statements regarding laxation and fiber and on carbohydrates and
diabetes. While some of these statements might not become guidelines,
the issues should be addressed in the technical report. She also felt
that it would be important to quantify the number of recommended
servings of whole grains. Dr. Lupton replied that the Subcommittee
would need to determine whether the science clearly supported making
such a recommendation. She noted that many studies stated a number of
servings without specifying the size of those servings, although some
of the better studies were now specifying grams of whole grains.
Dr. Lupton asked if the Subcommittee should draft a separate
conclusive statement regarding added sugars, or if they would be
treated as discretionary calories. Based on input from several
Committee members, King stated that the Subcommittee's primary tasks
in this area were to define the concept of discretionary calories and
clarify how many discretionary calories would be available in a
typical diet. Dr. Nicklas noted that it would be helpful for the
Committee to have an opportunity to address the question of including
starch under discretionary calories.
Dr. King turned the floor over to Dr. Kris-Etherton for a
discussion of the Fatty Acids Subcommittee's conclusive statements.
Fatty Acid Subcommittee
Conclusive Statements and Discussion
P. Kris-Etherton, Lead
Dr. Kris-Etherton noted that the members of the Subcommittee
included Drs. Camargo, Nicklas, and Go. She stated that the
Subcommittee had reviewed the literature in seven areas: total fat,
saturated fatty acids, cholesterol, trans fatty acids, omega-6
polyunsaturated fatty acid (n-6 PUFA), alpha-linolenic (α-linolenic)
acid, and fish.
Dr. Kris-Etherton stated the Subcommittee's conclusive statement in
this area: "Intake of total fat 20 to 35 percent of calories would be
consistent with the IOM Macronutrient report." She noted that the
Subcommittee had justified both the upper and lower end of this range.
At the upper end, there was a risk of increased calorie consumption,
as well as potential increased risk of cardiovascular disease. At the
lower end there was a risk of nutrient inadequacy and increased blood
Dr. Kris-Etherton acknowledged that there was some concern that it
could be difficult to meet some nutrient requirements within the 20 to
25 percent range. She stated that the recommended intake of linoleic
and µ-linolenic fatty acids could be met at these levels by using
certain oils and that USDA was conducting additional menu modeling to
determine which oils should be used.
Dr. Kris-Etherton noted that the Women's Health Initiative study had
shown that it was difficult to adhere to a diet with only 20 percent
of calories from fat, but the Subcommittee chose to include this level
because it would still be nutritionally adequate and some people were
able to follow such a diet.
Dr. Kris-Etherton turned the floor over to Dr. Go for a discussion on
the recommendations relative to cancer. She noted that Dr. Nicklas
would discuss recommendations for total fat for children following Dr.
Dr. Go stated that the Subcommittee's recommendation regarding total
levels of fat was sound with regard to cancer prevention. He noted
that he had reviewed data from the National Cancer Institute, the
International Agency for Research on Cancer of the World Health
Organization, and the American Institute for Cancer Research. Data
from numerous epidemiological and prospective studies showed a
positive association between breast and colorectal cancer and diets
high in saturated fat. A large European prospective study on nutrition
and cancer concluded that women who consume over 35 grams per day of
saturated fat had more than a two-fold increased risk of developing
breast cancer compared with those who consume less than 10 grams of
saturated fat per day. Data regarding fat intake and prostate cancer
was inconclusive. Dr. Go noted that it was not clear whether the
reduced risk of cancer associated with reduced fat diets was due to
lower total fat or increased intake of fruits and vegetables. However,
the recommendation of 20 to 35 percent of calories from fat was
consistent with the literature on cancer, particularly at the lower
end of the range.
Dr. Nicklas prefaced her remarks on total fat in children by
addressing several other aspects of the Subcommittee's conclusive
statement. First, she reiterated that the Subcommittee had looked at
the adequacy of nutrients at various levels of fat in the diet and had
found that at 20 percent of calories from fat, few of the proposed
food patterns met the recommended AI for linoleic and -linolenic
acids. The AI for both of those fatty acids was met at the 35 percent
level, but cholesterol levels were above 300 mg in the highest calorie
food pattern. Dr. Nicklas noted that the Subcommittee's
recommendations would include a list of recommended oils and food
sources for important nutrients, based on modeling exercises that USDA
was conducting. Dr. Nicklas also noted that intake of added sugars
increased dramatically at lower levels of fat intake. She stated that
the Fatty Acids Subcommittee would discuss this issue with the
Turning to the issue of fat intake for children, Dr. Nicklas stated
that the Subcommittee felt it was advisable to start with a higher
percentage of fat for children and work down, in order to ensure
nutritional adequacy. Dr. Kris-Etherton noted that the IOM had
established specific fat recommendations for different age levels.
However, the Subcommittee had decided to simplify the guidance by
stating that the recommended level for adults was 20 to 35 percent,
and that diets for children should be at the higher end of the
Saturated Fatty Acids
Dr. Kris-Etherton presented the Subcommittee's conclusive statement
on saturated fatty acids: "There is a positive linear trend between
saturated fatty acid intake and LDL concentration." She noted that
there was no plateau effect in this relationship.
The recommendation for the general public would be that saturated
fat consumption should be as low as possible while consuming a
nutritionally adequate diet. Dr. Kris-Etherton noted that the
Subcommittee had decided it would be important to quantify that
recommendation. Dr. Camargo stated that the proposed goals for
saturated fatty acid intake would be 10 percent of calories for adults
whose LDL cholesterol was below 130, and 7 percent for adults with an
elevated LDL cholesterol level. These goals were designed to harmonize
existing recommendations. Dr. Kris-Etherton stated that the
recommended goal for children would be less than 10 percent of
calories from saturated fat. She then opened the floor for discussion.
Dr. Weaver expressed concern that restricting saturated fatty acids
to 10 percent or less would limit flexibility in the food patterns by
forcing lean choices. Dr. Go and Dr. Kris-Etherton defended the 10
percent level, though Dr. Go acknowledged that the level for adults
with elevated cholesterol was much more stringent. This led to a
discussion of whether the recommendation should specify a level for
individuals with coronary heart disease or cardiovascular disease. It
was noted that the Guidelines were designed to help healthy
individuals reduce their risk for chronic disease, and that those with
prior history of a chronic disease would receive appropriate advice
from a physician. A consensus emerged that while it would be important
to address this issue in the technical report, the Guidelines should
be aimed at the healthy population.
Dr. Kris-Etherton presented the Subcommittee's conclusive statement
on cholesterol: "There is a positive linear trend between cholesterol
intake and LDL cholesterol concentrations and, therefore, with risk of
coronary heart disease." She asked Dr. Camargo to discuss the
Dr. Camargo stated that the Subcommittee would recommend that
cholesterol consumption should be as low as possible while consuming a
nutritionally adequate diet. Specific goals would be less than 300 mg
of dietary cholesterol per day for individuals whose LDL cholesterol
was below 130, and less than 200 mg per day for those with an elevated
LDL cholesterol. These goals were supported by evidence from the IOM
and were consistent with the ATP-III. He noted that daily cholesterol
intake in this country was currently 250 to 325 mg for adult men, and
180 to 200 mg for women.
Dr. Nicklas emphasized that these guidelines were intended for
adults and were not based on studies with children. Dr. Camargo noted
that there was nothing in the literature that addressed the question
of how saturated fat, cholesterol, and blood lipids ultimately affect
heart disease in children. Dr. Appel noted the importance of
establishing healthy dietary patterns early in life and suggested that
the report include a statement that the recommendations should be
adopted by children.
Trans Fatty Acids
Dr. Kris-Etherton presented the Subcommittee's conclusive
statement: "There is a positive linear trend between trans fatty
acid intake and LDL concentration." This conclusion was
consistent with the IOM report and several more recent publications.
Dr. Kris-Etherton stated that the Subcommittee felt that the
recommendation should be quantified and was still attempting to
determine appropriate limits of trans fatty acid intake. This task was
complicated by the fact that different organizations had set different
limits. For example, the Danish Nutrition Council recommended zero
trans fats, the World Health Organization recommended less than one
percent of calories, and the European Commission recommended less than
two percent of total calories.
Dr. Kris-Etherton noted that Americans were consuming 2.6 percent
of calories from trans fatty acids in the mid 1990s. More recent data
had shown that the level of trans fats in the food supply had
decreased appreciably, especially in certain foods and in certain
Dr. Kris-Etherton stated that the Subcommittee would like to
recommend that there be no industrial sources of trans fatty acids in
the diet, but it acknowledged that there were natural sources of trans
fatty acids, especially beef and cheese. The Subcommittee also
recognized that conjugated linoleic acid (CLA) was a natural trans
fatty acid that had some health benefits.
She noted that USDA was conducting some additional modeling
exercises to determine the level of trans fatty acids that would
remain in the diet if industrial sources were eliminated. She then
opened the floor for discussion.
Dr. Lupton asked whether there were any benefits of trans fats from
industrial sources that would be lost if those sources were eliminated
from the diet. Dr. Kris-Etherton acknowledged that some cardiologists
were advising patients to avoid some margarines that were widely
recommended for reducing cholesterol because they contained low levels
of trans fats in the form of hydrogenated soybean oil. Dr. Lupton
stated that she would prefer to see a recommendation that was based on
physiological effects rather than specifying industrial versus natural
sources. Dr. Kris-Etherton proposed that the recommendation could be
based on the specific fatty-acid composition of the trans fat.
Dr. Caballero felt that a reasonable goal for trans fats would be
around one percent, which would represent a significant reduction from
current intake. He questioned whether there was sufficient evidence
regarding the health effects of CLA to make a specific recommendation
regarding that fatty acid. Dr. Clydesdale stated that the isomers of
CLA in foods were not particularly active. Dr. King noted that while
the evidence from animal studies on CLA was fairly convincing, human
studies were inconclusive.
Dr. Weaver asked if substitutes were available for hydrogenated
oils in all categories of food. Dr. Clydesdale stated that substitutes
existed for some, but not all, hydrogenated oils and that it was
difficult to find acceptable substitutes for hydrogenated oils in
baked goods. Dr. Weaver expressed concern that a recommendation to
eliminate all industrial sources of trans fats would eliminate entire
categories of commercially prepared foods.
Dr. Kris-Etherton noted that Committee members were questioning
whether it would be feasible to eliminate all industrial sources of
trans fats. Dr. Camargo stated that since the food industry had shown
they were capable of and interested in eliminating trans fats, it
might be desirable to set the limit for industrial sources at zero,
while allowing small amounts from natural sources, including those
that might be in processed foods.
Dr. Clydesdale noted that the problem in finding acceptable
substitutes for trans fats in baked goods was the melting point. The
European food industry had reduced trans fat levels by substituting
tropical oils, but these were not acceptable to U.S. consumers. He
stated that the food industry was making efforts to reduce trans fats
and stressed that the Committee's recommendations should be realistic.
Dr. Go proposed setting the level for trans fat intake at less than
one percent of calories, without specifying industrial or natural
sources. He noted that this would represent a significant reduction
from current intake. Dr. Kris-Etherton suggested adding a qualifying
statement that would strongly encourage the food industry to eliminate
Dr. Clydesdale stated that he could not respond to that proposal
without data on the levels and sources of trans fats in the food
supply. Dr. Kris-Etherton and Dr. Camargo stated that the main
industrial sources of trans fats were baked goods (40 percent) and
margarines (18 percent). Twenty-one percent were from animal sources.
Dr. Camargo noted that setting the level at less than one percent
would make it essential to work with the food industry to help people
achieve that goal. Dr. Nicklas noted that this might be another area
in which flexibility could be offered. Dr. Camargo agreed that it
might not be reasonable to set the level at zero at present, but that
this would be an appropriate goal. Dr. Clydesdale agreed that it would
be appropriate to lower the level of trans fats, but he was
uncomfortable about setting a specific goal at this point in time.
Dr. Lupton reiterated her concern about a conclusive statement that
would make different recommendations for industrial versus natural
sources of trans fats without providing scientific evidence for that
distinction. In her view, the source of a trans fat was less important
than the substance itself.
Dr. King reminded the Committee of Dr. Beato's charge to aim high. She
stated that it might be important to recommend major changes in food
industry practices if the Committee could justify those changes. Dr.
Clydesdale stressed that it would also be important to acknowledge the
difficulty of finding stable substitutes for trans fats.
Omega-6 Polyunsaturated Fatty Acid (n-6 PUFA)
Dr. Kris-Etherton stated that the Subcommittee accepted the IOM
recommendation in this area. The conclusive statement would read:
"High intakes of n-6 PUFAs have been associated with blood lipid
profiles that are associated with low risk of coronary heart disease.
An intake between 5-10% of energy confers beneficial effects on CAD
mortality." Dr. Kris-Etherton noted that current intake was
approximately seven percent.
Dr. Nicklas stated that the Subcommittee would recommend further
research regarding the ratio of omega-6 to omega-3 (n-3) fatty acids.
Dr. Kris-Etherton stated that the Subcommittee was in the process
of drafting its recommendation in this area. The Subcommittee was
considering adopting the recommendation in the IOM report, but it was
still examining research regarding specific levels that might provide
The main question under consideration by the Subcommittee was
whether to recommend one number or a range. The IOM report established
an AI for alpha-linolenic acid of 1.1 grams for women and 1.6 grams
for men. Recommendations from the World Health Organization and the
European Commission were in the area of 1.2 percent of energy. A
recent report from the Agency for Health Care Research and Quality (AHRQ)
contained many recommendations regarding n-3 fatty acids and
cardiovascular disease. Dr. Kris-Etherton noted that the IOM
recommendations were based on appropriate levels to prevent nutrient
deficiency, while the goal of Dietary Guidelines was to identify
levels that would provide health benefits.
Dr. Nicklas added that the Subcommittee would recommend further
research regarding the conversion factor of ALA to EPA and DHA, and
also how omega-6 might interfere with that conversion rate.
Dr. Kris-Etherton stated that the Subcommittee would make a new
recommendation that Americans should consume eight to nine ounces of
omega-3 rich fish per week. This recommendation was based on
epidemiological and clinical data showing that omega-3 fatty acids
reduce the incidence of cardiovascular disease. It was also consistent
with the recommendations from the American Heart Association and the
European Society for Cardiology.
Dr. Kris-Etherton noted that the recommendation would represent a
doubling of current U.S. consumption of fish, according to USDA
databases. She then opened the floor for discussion.
In response to a question, Dr. Kris-Etherton stated that the
Subcommittee would prepare a table showing types of fish that were
high in omega-3. The list would include several kinds of canned fish,
which could help control costs.
In response to a question, Dr. Clydesdale stated that the Food
Safety Subcommittee planned to address the Food and Drug
Administration (FDA) advisory regarding consumption of fish by
pregnant women and young children. He noted that the types of fish
that should be avoided due to methylmercury and those that were safe
to consume were consistent with the Fatty Acids Subcommittee's
recommendations. Dr. Kris-Etherton noted that her Subcommittee would
address the issue of PCBs in farm-raised fish.
Dr. Appel expressed concern that the Subcommittee was recommending
a food source of a nutrient for which there was not a nutrient
recommendation and suggested that it might be preferable to simply
recommend two servings of fish, without making reference to omega-3.
Dr. Nicklas and Dr. King agreed that the point was well taken, and Dr.
Kris-Etherton stated that the Subcommittee would discuss the issue.
Dr. King asked what the Subcommittee would recommend for people who
would not eat fish. Dr. Kris-Etherton suggested that vegetarians or
people who do not eat fish could meet the recommendations through
plant-based sources of EPA and DHA. Dr. Kris-Etherton noted that the
conclusions regarding fish consumption and cardiovascular disease from
epidemiological studies were based on fish consumption, but that
similar results had been found in the Diet and Reinfarction Trial
(DART) study, which provided supplements for people who did not eat
fish. Dr. Appel noted that the DART trial was a secondary prevention
study with individuals who had suffered myocardial infarctions and
that there was no supplement study on a healthy population.
Dr. Clydesdale noted that plant sources of omega-3 tended to go
rancid very rapidly and that it would be necessary to find a way to
stabilize them before they could be added to foods.
Dr. King reminded the Committee of the importance of considering
the needs of pregnant and lactating women when they were making their
dietary recommendations. She noted that lipid levels changed
dramatically during pregnancy and suggested that it might be important
to state that some of the thresholds would not apply to pregnant
women. Dr. Kris-Etherton confirmed that the proposed levels of fat
intake would ensure adequate intake of vitamin B6, vitamin B12, and
Questions Still Being Reviewed
Dr. Kris-Etherton stated that the Subcommittee would review the
modeling exercises to come up with a quantitative recommendation for
trans fatty acids and α-linolenic
acid. It would also be reviewing monounsaturated fatty acids, stearic
acid, and CLA. Dr. Nicklas added that the Subcommittee would also
discuss the question of a recommendation on EPA and DHA.
Dr. King reminded the Committee that the report would be making
many recommendations that would be unfamiliar to the general public
and that it would need to provide guidance on how to implement those
recommendations in dietary planning.
The Fatty Acid Subcommittee consulted with Dr. Bill Harris of St.
Luke's Lipid and Diabetes Research Center regarding fish oils and
Dr. Kris-Etherton turned the floor over to Dr. King, who adjourned
the meeting for a brief break.
Dr. King reconvened the meeting and noted that in January, the
Committee had created a new Macronutrient Subcommittee to address the
issue of the carbohydrate/fat ratio in the diet. She then turned the
floor over to Dr. Caballero to present the Macronutrient
Macronutrient Ratio Subcommittee
Conclusive Statements and Discussion
B. Caballero, Lead
Dr. Caballero stated that the members of the Subcommittee included
Drs. Kris-Etherton, Lupton, Weaver, and Pi-Sunyer, with additional
input from Dr. King. He noted that the IOM macronutrient report had
addressed the macronutrient ratio for the first time and had defined
the concepts of acceptable distribution ranges for protein,
carbohydrates, and fat. He noted that while there was no upper level
in terms of absolute amounts of protein, fats had both a numerical
quantitative amount recommended, as well as a recommended range in
terms of percent of total calories from fat.
The Macronutrient Subcommittee reviewed the issue of the ratio of
carbohydrates to fat in terms of maintenance of a healthy weight and
weight loss. Dr. Caballero noted that this is a controversial issue.
Dr. Caballero stated that after reviewing extensive evidence, it
had developed the following conclusive statement: "Total energy intake
is more important for maintenance of a healthy body weight than the
relative contribution of fat, carbohydrate, or protein. Similarly,
reducing excess body weight requires a reduction in caloric intake
and/or an increase in energy expenditure (physical activity)."
The Subcommittee found no consistent evidence from long-term
studies in humans showing the advantage of either high-fat or
high-carbohydrate diets for weight maintenance or loss. Ranges of 20
to 35 percent of calories from fat were well documented in studies
cited in the IOM report. Dr. Caballero noted that the studies that the
Subcommittee reviewed included little information on levels of
Dr. Pi-Sunyer stressed that it was essential to emphasize the
message about total caloric intake as opposed to any specific ratio of
fat to carbohydrates. Dr. Pate noted that there was a broad public
perception that changing this ratio could bring about weight loss. He
suggested adding a corollary indicating that while modifying the ratio
might be associated with weight loss, this benefit was probably due to
reduced caloric intake.
Dr. Nicklas asked if the Subcommittee would recommend an
appropriate amount of weight loss per week. Dr. Pi-Sunyer stated that
this would be addressed in a separate section on weight loss in the
Subcommittee's report. Dr. Caballero noted that this would be a
general statement, along the lines of what was in the 2000 Dietary
Dr. King noted that this would be the first time that the
Guidelines would propose a range of fat intake rather than a specific
number and that the upper limit was higher than had been suggested in
the past. Dr. Caballero added that the bottom end of the range would
also be lower than in the past.
Dr. Appel noted that the upper range might be linked to higher
caloric intake or higher activity levels. Dr. Lupton agreed that as
the percentage of fat increased, fewer calories would be available for
other macronutrients. In some food patterns there were no
discretionary calories at fat levels of 35 percent. Dr. Caballero
noted that the Subcommittee's report would need to include a statement
that individuals with low total energy requirements would have to
choose their foods carefully in order to avoid essential fatty acid
deficiencies at the lower end of the fat intake range and to avoid
excess calories at the higher end of the range. Dr. Nicklas suggested
that the Subcommittee could reference the Fatty Acid Subcommittee's
report, which would address the issue of potential deficiencies at low
levels of fat intake.
Dr. Caballero stated that the Subcommittee was still reviewing the
concept of discretionary calories to develop a definition, determine
what macronutrient components would be included, and determine the
message to be conveyed to the public regarding the link between
discretionary calories and physical activity.
Dr. King asked for the Committee's input as to whether the concept
of discretionary calories could be communicated effectively to the
public. Dr. Caballero acknowledged that it would be difficult to
explain how to calculate discretionary calories and expressed concern
that the concept could be abused. Dr. Pate stressed the importance of
including discretionary calories in the recommendations and noted that
resources would be available to develop communications strategies.
Dr. Camargo noted that implementing the concept of discretionary
calories assumed that people could determine their appropriate caloric
intake, based on body size and activity level, and could keep track of
what they were eating and how much exercise they were getting. He made
an analogy to balancing a bank account by keeping track of income and
expenses and emphasized the importance of simple tools to help people
measure intake and expenditure of calories, such as labeling foods
with caloric content and encouraging the use of pedometers.
A brief discussion ensued regarding the impact of physical activity
on discretionary calories. Dr. Pi-Sunyer proposed that consumer
materials addressing this topic should include a simple message:
"Sedentary people do not have discretionary calories; if you want
them, you need to be active."
Dr. King asked the Committee what types of foods would constitute
discretionary calories. Responses included added sugar, added fat, and
starchy foods. Dr. Caballero noted that discretionary calories could
be any type of food.
Dr. Bronner emphasized that only a small proportion of the
population followed the current food guidance. She expressed concern
that people who did not understand the basic concepts of healthy
eating would now be expected to understand their energy requirements.
She stressed the importance of ensuring that people had the proper
foundation to enable them to take the steps the Committee was asking
them to make.
Dr. Caballero stated that BMI was a good indicator of whether a
person was consuming the proper amount of calories. He noted that he
was working on a computer application to help people determine their
appropriate caloric intake. Dr. Pate added that it would be important
to establish and define physical activity levels, including at least
three categories above sedentary.
Dr. Lupton noted that a national campaign had been effective in
raising awareness of HDL and LDL cholesterol and suggested a similar
process to inform the public about discretionary calories.
Dr. Appel cautioned that people were generally resistant to
counting calories. Dr. Weaver suggested that computer applications
could help. Dr. Camargo noted that it could be difficult to gauge the
calories in foods, but that the bank account model could work because
people understand how to balance income and expenses. Dr. Pate noted
that a campaign would have to take many forms. While only a small
percentage of people were likely to implement the advice, he would
consider the campaign to be effective if most Americans understood
that they would have more flexibility in their diet if they were more
Dr. Bronner noted, and others agreed, that a simple bathroom scale
was a useful tool for monitoring weight. Dr. Caballero noted that
people are not always aware that they are gaining weight. Dr. Camargo
acknowledged that a scale could help to identify the problem, but that
the solution would be a greater focus on calories. He stressed a need
for better information regarding calories in packaged foods and in
foods served at chain restaurants. Dr. Caballero agreed that energy
density and portion size were difficult to gauge and could be
Dr. King asked the Committee to focus on what it would recommend to
the Subcommittee. After some discussion, a consensus emerged that the
Subcommittee should continue to refine the concept of discretionary
calories and to consider what types of foods would be included.
Ms. McMurry reminded Committee members that their job was to
determine which concepts would be important to convey and to provide
scientific evidence for their recommendations. HHS and USDA would be
responsible for developing a communications plan for the Guidelines.
Dr. King thanked the Macronutrient Subcommittee for its
presentation. Turning to a discussion of overarching issues, she
raised the question of whether the Committee wished to propose any
alternatives to the term "serving size." Dr. Weaver stated that the
Nutrient Adequacy Subcommittee had used household measures, such as
cups and ounces, to describe recommended amounts of food. Dr. Pi-Sunyer
was concerned that consumers would not understand how to translate
grams into specific amounts of food, such as fiber; Dr. King noted
that food labels showed fiber content in terms of grams. There was
general agreement that household measures would be preferable to the
term "serving size."
Dr. King then reviewed a draft outline for the section of the
Committee's final report that would translate the technical literature
review into food-based dietary guidelines. The outline
included four main sections:
- Choose foods that provide nutrient needs
- Aim for energy balance
- Make dietary and lifestyle choices that reduce the risk of
- Keep food safe to eat
The first section would provide a list of foods that provide needed
nutrients. It would also include discussions of Recommended Daily
Allowance (RDAs) and upper limits; nutrient density and adequacy;
vitamins, minerals, and electrolytes; and fluids. It would also
discuss flexibility in food choices to meet nutritional goals, such as
replacing whole grains with legumes or fruits and vegetables, and
options for a nutrient adequate vegetarian diet.
The second section would include discussions of physical activity;
energy density; BMI (including the impact of portion sizes, breakfast,
and fruits and vegetables); and weight loss. Dr. King noted that
discretionary calories could be addressed in this section.
The third section would discuss the major chronic diseases for
which risk could be reduced by choosing a healthy diet, including
cardiovascular disease, obesity, diabetes, and cancer. It would also
include discussions of the role of carbohydrates such as fiber and
fruits and vegetables in reducing the risks of heart disease; the
risks of added sugars for diabetes; the role of various fats; the role
of alcohol and chronic disease; sodium intake and hypertension; and
the role of diet in bone health.
The final section of the report would present guidance for food
Dr. King opened the floor for discussion.
Dr. Caballero suggested that, in light of the prevalence of
obesity, the first section should address energy balance. Other
Committee members stated that it was more logical to address nutrient
adequacy first, because this was the focus of the Dietary
Dr. Nicklas and Dr. Camargo stated that the section on Nutrient
Adequacy would include a discussion of the primary nutrients supplied
by each food group.
Dr. Nicklas proposed that the third section should refer to choices
that would prevent, rather than reduce, the risk of chronic disease,
because the Guidelines would also address children. Several Committee
members felt that it would be inadvisable to use the term "prevent."
Dr. King noted that establishing good dietary habits in children early
in life would reduce their risk of disease later in life.
Dr. Bronner noted that bone health would be included in the overall
discussion of calcium because the lifecycle components of bone health
could not be distinguished in the literature.
Dr. Lupton asked whether the nutrient adequacy section would
include a separate discussion of supplements, or if they would be
discussed in those areas where the food patterns fell short of
recommended levels. Dr. Weaver stated that the Nutrient Adequacy
Subcommittee would discuss supplements in the context of specific
vitamins for which the food patterns did not meet the requirements for
certain groups. She noted that the Subcommittee was not working on a
generic statement regarding supplements.
Dr. Kris-Etherton asked if the energy balance section would include
a discussion of macronutrients. Dr. King noted that this was a good
suggestion and acknowledged that the proposed outline was a first
draft that would continue to evolve. She thanked the outside experts
and the Subcommittees for their excellent presentations and reviewed
the agenda for the following day.
Ms. McMurry informed the audience that the notebook for the meeting
was available in the lobby and that copies of any of the materials
would be available at her office, by appointment.
Dr. King adjourned the meeting at 5:15 p.m.
Wednesday, March 31
Dr. King welcomed Committee members and observers to the second day
of the meeting. She stated that the morning session would continue the
review of the Subcommittee's conclusive statements, the rationale for
those statements, and critical discussion by the full Committee. She
encouraged Committee members to challenge each other to ensure that
they developed the best possible conclusive statements, based on the
Dr. King reminded the audience that they were welcome to submit
comments regarding the Committee's deliberations to Kathryn McMurry at
HHS and explained that there was no time for public comments during
this meeting. She emphasized that the Committee appreciated public
input and considered all comments. Dr. King then turned the floor over
to Dr. Pi-Sunyer and the Energy Balance Subcommittee.
Energy Balance Subcommittee
Conclusive Statements and Discussion
X. Pi-Sunyer, Lead
Dr. Pi-Sunyer noted that the members of the Energy Balance
Subcommittee included Drs. Pate, Caballero, and Appel, with additional
contributions from Dr. King. Dr. Pi-Sunyer and other Subcommittee
members then presented the Subcommittee's conclusions and
recommendations in seven areas: breakfast and BMI; physical activity
and prevention of weight gain; physical activity and maintenance of
weight loss; energy density and BMI; portion size and BMI; fruits and
vegetables and BMI; and calcium/dairy and BMI.
Breakfast and BMI
Dr. Pi-Sunyer stated that after reviewing the literature regarding
breakfast and BMI, the Subcommittee had drafted the following
statement: "The effects of regularly eating breakfast on BMI are
uncertain." He noted that the data regarding this relationship
were inconsistent. One randomized clinical trial and two longitudinal
studies showed no significant differences between groups who ate
breakfast and control groups, while a number of cross-sectional
studies had reported positive associations between skipping breakfast
and adiposity in children. Information from the U.S. National Weight
Loss Registry also indicated that eating breakfast was an important
factor in maintaining weight loss over time. An analysis of data from
the Nationwide Food Consumption Survey suggested that skipping
breakfast lowered the nutritional quality of the diet of adults and
Dr. Pi-Sunyer opened the floor for discussion.
Dr. Clydesdale expressed concern that the statement could imply
that eating breakfast was not important. Dr. Pi-Sunyer replied that
the rationale would state that eating breakfast was likely to be of
nutritional benefit, though its association with BMI was unclear.
Dr. Weaver asked if the statement could include a caveat that it
would not only be nutrient adequate, but could also be helpful for
performance, especially for school-age children. Dr. Pi-Sunyer replied
that the Subcommittee's mandate had been to address breakfast and BMI;
it had not been asked to address performance in school.
Dr. Caballero noted that the Subcommittee's mandate was to examine
energy balance and that skipping breakfast would have an influence.
Dr. Nicklas stated that many of the studies on breakfast had examined
its impact on nutrient adequacy. She offered to provide summaries of
those studies, as well a studies on performance.
Dr. King asked if there was any data on skipping meals other than
breakfast. Dr. Pi-Sunyer stated that there was some data to suggest
that eating more meals throughout the day was associated with lower
BMI, but he cautioned that there were few long-term studies examining
the effects of various eating patterns. Dr. Nicklas noted that some
studies had implied that increased snacking could be a predictor of an
increase in BMI, while the results of other studies were contrary to
Dr. Camargo suggested that the Subcommittee could state, "Breakfast
has many proven benefits," and could then cite the extensive
literature in support of that statement. He recommended discussing
breakfast in the context of the impact of energy balance on BMI. Dr.
Pi-Sunyer reacted favorably to that suggestion.
Physical Activity and Prevention of Weight Gain
Dr. Pate stated that the Subcommittee had devoted considerable
attention to the issue of how much physical activity might be
recommended for prevention of excessive weight gain or obesity. While
it was continuing to revise its message, it had reached consensus on
key concepts. Its proposed conclusive statement was: "Thirty minutes
of physical activity per day contributes importantly to maintenance of
healthy weight and provides other important health benefits. More than
30 minutes of physical activity daily provides added health benefits,
and many adults may require up to 60 minutes per day to prevent
excessive weight gain."
Dr. Pate noted that the Subcommittee had focused on crafting a
conclusive statement that would draw together two types of background
information: the recent CDC report, which confirmed the relevance of
the 30-minute recommendation, and the IOM Macronutrient report and
other recent consensus reports that indicated that many adults would
require more than 30 minutes and possibly as much as 60 minutes of
daily physical activity to prevent obesity.
Dr. Pate anticipated that the Subcommittee had discussed physical
activity recommendations for children and proposed to recommend at
least 60 minutes of physical activity per day, which is consistent
with the CDC report. He then opened the floor for discussion.
In response to a question from Dr. King, Dr. Pate stated that the
Subcommittee was still thinking about how to quantify the amount of
physical activity, but that the recommended frequency would probably
be five days per week for adults and seven days for children. He noted
that recommendations had an impact on the way surveillance systems
were developed and suggested that the Subcommittee would consider that
fact when finalizing its report.
Several Committee members raised questions regarding the types of
physical activity that would be recommended for children. Dr. Pate
stated that some of the international consensus statements had
developed good language indicating that children and youth can and
should accumulate physical activity in age-appropriate ways. The
Subcommittee was still considering how to integrate resistance and
bone-loading exercise into the overall recommendations. Dr. Pate noted
that the Subcommittee had requested an analysis of NHANES data to
determine the most common forms of physical activity among U.S. adults
and would use those lists as examples of the types of activity that
could be used to meet the recommendations.
Dr. Weaver expressed concern about the lack of data regarding the
relative benefits of aerobic activity versus resistance and
bone-loading exercise. Dr. Pate replied that the 30-minute
recommendation was based on caloric expenditure. He acknowledged that
most forms of activity contribute to caloric expenditure, but he
stressed that aerobic activity resulted in greater caloric expenditure
than resistance and bone-loading exercise.
Responding to questions about recommendations for special groups,
Dr. Pate agreed that it would be important address the physical
activity needs of the elderly and stated that the Subcommittee hoped
to have an opportunity to review the forthcoming CDC report on that
topic. The Subcommittee would also incorporate physical activity
guidelines for pregnant women that had been developed by other groups.
Dr. Weaver asked how the Subcommittee would provide any guidance
regarding how to get the recommended amount of physical activity. Dr.
Pate noted that the 30-minute recommendation was for activity above
and beyond normal light activity and acknowledged that communicating
that fact to the public had been a challenge. He stated that the
baseline of "light activity" on top of which the 30 minutes would be
added was different that it might have been some years ago and
expressed concern that there was little population data in that area.
Dr. Weaver stated that she could provide a study on the amount of bone
loading over the course of a day versus an hour of intentional
exercise, and Dr. Camargo noted that there was a growing body of
research on inactivity as a predictor of BMI. Dr. Pate agreed that it
would make sense to allude to the impact of inactivity on BMI. He
noted that several studies in children had shown that reducing TV
watching and other forms of inactivity had a beneficial impact on BMI.
Those studies did not show increases in measurable physical activity,
which would suggest that sedentary time had been replaced by light
activity, which was not detectable with the measures that were used in
Dr. Lupton noted that physical activity contributed to health in
many ways and that it would be important to address its contribution
in areas other than energy balance, such as bone health. Dr. Pate
replied that the Subcommittee was considering how to address all
elements of physical activity in the final report. One approach would
be to address all of the benefits of physical activity in a dedicated
section of the report. Another option would be to discuss the
contribution of physical activity to energy balance in the section on
energy balance, and to address other benefits elsewhere in the report.
Referring to the draft outline that had been reviewed the previous
day, Dr. King stated that physical activity was listed in the section
on risk of chronic disease because of its impact on obesity. She noted
that it also played a role in energy balance and could potentially be
relevant to other sections, such as nutrient adequacy. Other Committee
members suggested that physical activity should be included in the
discussion of discretionary calories.
Physical Activity and Maintenance of Weight Loss
Dr. Caballero presented the Subcommittee's proposed conclusive
statement: "While the contribution of physical activity to weight loss
usually is modest, acquiring a routine of regular physical activity
will greatly help an individual to maintain a stable body weight after
successful weight loss. The amount of physical activity that formerly
obese persons require to avoid weight regain is estimated to be from
60 to 90 minutes daily at a level of brisk walking. This amount is
higher than the amount that never-obese persons usually require to
maintain their weight."
Dr. Caballero cited supporting evidence from two types of studies:
epidemiological follow-up studies of six months to several years with
individuals who had lost weight, and shorter-term studies in which
doubly labeled water was used to measure the contribution of physical
activity to total daily energy expenditure. Consistent and compelling
data from both types of studies indicated that individuals who had
lost weight would require 60 to 90 minutes of daily physical activity
to maintain a stable body weight, as opposed to 45 to 60 minutes of
daily activity for those who were never obese.
Dr. Caballero noted that while physical activity might contribute
less to weight loss than diet, there was some evidence that people who
began a regimen of physical activity during the weight loss period
appeared to be more likely to maintain a consistent level of activity
following the weight loss and thus maintain a stable weight. He then
opened the floor for discussion.
In response to a question, Drs. Caballero and Pate stated that they
did not know of any data regarding the amount of activity that would
be required for individuals who were slightly overweight but not obese
to maintain a stable weight. Most studies regarding physical activity
and BMI were on obese or formerly obese individuals.
Dr. Pi-Sunyer asked if there was any implication that persons who
engaged in 60 to 90 minutes of physical activity could eat whatever
they wanted. Dr. Pi-Sunyer stated that while the follow-up studies did
not measure food intake, there appeared to be a positive relationship
between the amount of physical activity and ability to regulate
intake, though the mechanism was not clear. Dr. Caballero noted that
subjects in those studies were on an ad libitum diet. Dr. Pi-Sunyer
noted that individuals in the National Weight Loss Registry tended to
eat a low-fat diet and tended to eat more than three meals per day.
Dr. Kris-Etherton asked whether it was possible to quantify how
much weight someone would gain if they exercised for only 30 minutes.
Dr. Caballero stated that the follow-up studies showed a dose
response. Those who did not exercise regained the most weight, those
who exercised for 30 minutes regained less weight, and those who
exercised for 60 minutes or more regained little or no weight.
Dr. Appel asked whether 60 to 90 minutes was actually required to
maintain weight loss, or if that level was simply associated with
maintaining a stable weight. Dr. Caballero stated that the statement
could be reworded to describe the association.
Dr. Lupton felt that it would be important to link post-weight loss
physical activity requirements with energy intake and expressed
concern that some people would assume that they could compensate for a
higher level of physical activity by consuming additional calories.
She suggested including a caveat to address that issue and asked the
Subcommittee to clarify why formerly obese individuals would require
more exercise than those who were never obese to balance similar
energy intake levels. Dr. Pi-Sunyer stated that the difference could
be due to changes in metabolic rate and caloric requirements following
weight loss, but the mechanism was not well understood. Dr. Caballero
noted that caloric intake was difficult to determine in follow-up
studies. Although some studies did report caloric intake, the data was
inconsistent due to differences in the method of calculating intake.
Dr. King stressed the importance of providing a scientific rationale
for the statement.
Referring to a study that showed a broad range of weight loss with
twins who followed the same regimens, Dr. King noted that the process
of weight loss was not straightforward and that differences in
efficiency between people were not well understood.
Dr. Bronner asked whether the doubly labeled water studies provided
any indication of the proportion of caloric expenditure that was
attributable to intentional physical activity versus activities of
daily living. Dr. Caballero noted that the doubly labeled water
studies measured average daily energy expenditure but did not
discriminate between types of activities. The survey questionnaires
used for the follow-up studies provided data on types of activities,
but did not provide exact calorie expenditures.
Energy Density and BMI
Dr. Caballero also presented the Subcommittee's statement in this
area: "Consuming high-energy density foods may facilitate excess
caloric intake by packing more calories in a smaller volume of food
and by delaying the sensation of fullness/satiety after a meal.
Conversely, consuming low-energy density foods may help keep caloric
intake under control. Evidence is not available to link the energy
density of food intake to BMI. Considering the available evidence,
however, it seems prudent to recommend that low-energy dense foods be
used as a means to keep calories under control. This advice is
consistent with the recommendation to consume a plant-based diet."
Dr. Caballero stated that short-term studies indicated that energy
density affects caloric intake, but there was no solid data linking
the energy density of foods with BMI. He then opened the floor for
Dr. Kris-Etherton and others stated that this issue should be
presented in the context of the whole diet and overall energy balance.
They noted that some energy-dense foods, such as fats and oils, were
high in nutrient density and an important part of an overall
low-energy dense diet, while some low-energy dense foods, such as
beverages with added sugars, were nutrient poor. Dr. Pi-Sunyer agreed
that these issues could be addressed in a discussion of strategies to
achieve an overall low-energy dense diet. After some discussion, there
was agreement that this statement should be used as supporting
information for recommendations about the importance of energy balance
within the diet and should not be treated as a major topic within the
translation section of the report.
In response to a question, Dr. Caballero stated that the
Subcommittee had used Dr. Rolls' definition of energy density, which
was "calories per gram." He noted that there was no consensus
definition, but it was much more difficult to calculate by volume than
Dr. Appel asked if any section of the report would address the
issue that had been raised by Dr. Mattes regarding the apparent
difficulty of regulating or compensating for intake of calories from
beverages. Committee members suggested that this issue should also be
considered as part of the overall discussion of energy balance. Dr.
King suggested that the Committee should review the literature that
had been presented the previous day and incorporate the references
into the report.
Dr. Nicklas expressed concern that there were few long-term studies
on regulation of energy intake. Dr. Caballero noted that the
Subcommittee had requested an analysis of NHANES data to look at
energy density of reported food intake. This data could be used to
illustrate the practical aspects of energy density and to determine
whether there was a trend toward greater consumption of energy dense
foods. Dr. Nicklas suggested that total calories should be considered
in the context of total nutritional intake.
Portion Size and BMI
Dr. Caballero presented the Subcommittee's conclusive statement:
"The amount of food offered to a person influences how much he/she
eats, and most studies have shown that more calories are consumed when
a large portion is served compared with a small portion. The impact of
portion size on energy intake is greatest for foods with high energy
Dr. Caballero stated that while the literature consistently showed
that portion sizes and BMI had both increased over time, there was no
clear evidence that those findings were associated. He noted that
studies had shown the effect of portion size on intake in the
short-term, but there were no long-term studies examining the impact
of portion size on BMI. However, the Subcommittee felt it would be
important to address this issue in the report.
Committee members agreed that it was extremely important to discuss
portion size and that the statement had implications for both the food
industry and the food service industry. Dr. Nicklas offered to provide
additional studies. Dr. King stated that she understood the
Subcommittee would have additional references beyond those that it had
Fruits and Vegetables and BMI
Dr. Appel stated that the Subcommittee had found limited evidence
on the effects of increased fruit and vegetable intake in facilitating
weight loss or maintaining healthy weight. Most of the data was
observational. There were few prospective studies, and it was
difficult to separate out the fruit and vegetable component of those
studies. The larger studies tended to support increased fruit and
vegetable consumption, but the evidence was not strong. There were no
studies in which fruits and vegetables were the exclusive
Based on the limitations of the evidence, Dr. Appel suggested that
this issue should be addressed in the context of the recommendation to
consume a low-energy dense diet.
Dr. Go asked if there was any indication of the relative benefits
of fruits versus vegetables. Dr. Appel noted that one study had shown
increased intake of vegetables was associated with greater weight loss
in boys. Dr. Nicklas stated that she could share a paper in which
fruit was inversely associated with overweight.
Calcium/Dairy and BMI
Dr. King presented the Subcommittee's statement on this topic:
"While the evidence is inconclusive that dairy foods help manage body
weight, there is no evidence that consuming the recommended intakes of
low-fat dairy foods increases body weight. Therefore, adults and
children should not avoid dairy foods due to concern that these foods
are 'fattening.' "
Dr. King described two weight loss studies that had shown a
significant negative relationship between calcium or dairy product
intake and body weight or fat. These findings suggested there could be
some benefit of including dairy foods in a diet for weight loss;
however, the studies were small and the methods were quite different
between the two studies. The findings of longitudinal studies looking
at dairy food consumption and body weight or body fat in children were
Dr. King stated that the lack of large scale, randomized controlled
trials or controlled feeding studies that were explicitly designed to
address the issue of dairy food consumption or calcium consumption and
body weight or body fat made it difficult to make a conclusive
statement regarding the intake of dairy foods and the management of
Dr. King noted that none of the studies had shown that dairy food
consumption was associated with an increase in body weight. She stated
that there was no need to avoid dairy foods for fear that they were
fattening, as long as they were consumed within the recommended
amounts, based on the proposed food patterns.
Dr. Go suggested, and Dr. King agreed, that this topic should also
be discussed in the context of the larger discussion of energy
balance. Dr. Nicklas suggested adopting the language similar to what
had been drafted by the Energy Balance Subcommittee ("There is no
conclusive evidence to suggest … nevertheless, it seems prudent to
recommend ...") for the statements on fruits and vegetables and
calcium and dairy. Dr. Clydesdale suggested that this language could
be applied to the statement on breakfast and BMI.
Dr. Lupton asked if it was possible to separate studies that looked
at calcium-rich foods from those that looked at dairy products. Dr.
King said that would be easy to do.
Dr. Caballero stressed that it would be important to clarify what
types of dairy products were recommended. Dr. Weaver noted that
studies with children were not based on skim milk and that it may not
be appropriate to imply that the relationship between dairy product
intake and body weight was only true for low-fat products.
Issues Still Being Addressed
Dr. Pi-Sunyer noted that the Subcommittee was still drafting
statements on weight loss advice and on eating disorders.
Dr. Pi-Sunyer acknowledged the contributions of Dr. Rolls and
Mattes regarding energy density and portion sizes; Dr. Kohl regarding
physical activity recommendations of other groups; and Dr. Cliff
Johnson and Ms. Alanna Moshfegh regarding NHANES and CSFII data and
energy intake, and regarding energy density and portion sizes.
Dr. King adjourned the meeting for a short break.
Dr. King reconvened the meeting and noted that Dr. Vernon Young had
passed away the previous evening. She acknowledged Dr. Young's
many contributions to the field of nutrition and then turned the floor
over to Dr. Appel and the Fluid and Electrolytes Subcommittee.
Fluid and Electrolytes Subcommittee
Conclusive Statements and Discussion
L. Appel, Lead
Dr. Appel stated that the Subcommittee had drafted conclusive
statements regarding water, potassium, and sodium and had considered
the question of whether the Adequate Intake (AI) for potassium and
sodium should be adjusted for calories. He noted that much of the
Subcommittee's work was based on the recently issued IOM report on
fluid and electrolytes.
Dr. Appel stated that it was difficult to develop a single
recommendation for water. Minimal daily water losses and production,
exclusive of sweating, resulted in a net requirement of one to three
liters, but high levels of physical activity or extreme environmental
conditions could raise the requirement to as much as 12 liters. He
noted that these figures were based on modeling and not empirical
Dr. Appel stated that the primary determinant of water requirements
was not chronic illness, but maintaining adequate hydration, for which
the best indicator was serum osmolality. NHANES data, stratified by
deciles of total water intake, showed that serum osmolality was
essentially identical at all levels. This would suggest that
homeostatic mechanisms allow for proper hydration. Although the IOM
panel found limited evidence associating high water intake with
reduced risk of bladder or colon cancer, and some evidence that it
could prevent kidney stones, the evidence did not merit setting a
specific requirement for the general population.
The Subcommittee's conclusive statement, based largely on the IOM
report, was: "The combination of thirst and normal drinking
behavior, especially the consumption of fluids with meals, is
sufficient to maintain normal hydration."
The Subcommittee would not recommend a specific intake level, such
as eight glasses of water per day. However, the Subcommittee
recognized that water intake should be deliberately increased with
prolonged physical activity or exposure to heat stress. He then opened
the floor for discussion.
Dr. Kris-Etherton asked if the Subcommittee had considered the
needs of breastfeeding women. Dr. Appel replied that there was no
group for which the IOM found a significant difference in hydration
and that serum osmolality levels were actually slightly lower for
Dr. Nicklas asked whether the definition of fluid intake included
water from foods and from beverages other than water. Dr. Appel stated
that fluid intake was based on water from all sources. He noted that
in the NHANES database, 80 percent of fluid intake was from beverages,
and the balance was from foods.
Dr. Pi-Sunyer asked Dr. Appel to comment on the common perception
that water could contribute to weight loss by inhibiting appetite. Dr.
Appel noted that the Subcommittee had not addressed the issue of water
and weight loss but that it could comment on it in its conclusive
statement. The Subcommittee would also clarify that the conclusive
statement was based on total water intake, including beverages and
As background to the next conclusive statements, Dr. Appel
presented information on the effects of potassium and sodium on blood
pressure. He stated that there was a direct, progressive relationship
between blood pressure and cardiovascular disease, with lower blood
pressure directly associated with lower risk of cardiovascular
mortality. Dr. Appel noted that the contemporary approach to blood
pressure-related risks, based on epidemiological data, was not that
people were either hypertensive or non-hypertensive, but that the
relationship between blood pressure and risk of cardiovascular disease
was graded and continuous. He presented data from a recent
meta-analysis of the risk of stroke at various blood pressure levels
to illustrate that relationship.
Dr. Appel stated that most hypertension experts believed that it
was preferable for blood pressure to be as low as possible. He
presented projections showing that slight shifts in the blood pressure
levels in the general population could result in substantial reduction
of risks for mortality in terms of stroke, coronary heart disease, or
total mortality. Citing the Framingham heart study, Dr. Appel noted
that the estimated lifetime risk of developing hypertension was
approximately 90 percent.
Dr. Appel stated that potassium was one of many dietary factors
affecting blood pressure. The effects of potassium on blood pressure
were evidenced in both meta-analysis and controlled feeding studies.
Dr. Appel cited findings in several areas that supported a
recommendation to increase intake of potassium. First, dietary
patterns rich in potassium such as the Dietary Approaches to Stop
Hypertension (DASH) diet had been associated with lower blood
pressure, with much greater reduction among African Americans. Dr.
Appel suggested that this finding could be helpful in addressing
health disparities in this area. Second, potassium was found to reduce
the effects on blood pressure of increased salt intake. Again, the
response was greater among African Americans. Third, potassium intake
was associated in observational studies with lower risk of developing
kidney stones. Finally, observational, cross-sectional, and
prospective data documented a direct relationship between potassium
intake and bone mineral density. Dr. Appel noted the need for
randomized clinical trials to test that relationship.
Based on this body of evidence, the IOM panel recommended 120
millimoles (mmol) per day as an adequate intake of potassium for
adults. Dr. Appel noted that the recommended level was significantly
higher than current median intake levels (84 mmol per day in men and
65 in women). He noted that African Americans would especially benefit
from increased intake of potassium, given their relatively low intake
of potassium and high rates of elevated blood pressure and salt
sensitivity. Dr. Appel stated that there was no upper limit for
potassium intake. He acknowledged that increased potassium could be
problematic for individuals who have impaired urinary potassium
excretion as a result of drugs or medical conditions, such as diabetes
and chronic renal insufficiency, but he noted that those individuals
would not be included in recommendations for the general public.
Dr. Appel stated that, based on the evidence, the Subcommittee had
drafted the following conclusive statement on potassium: :Diets rich
in potassium can lower blood pressure, mitigate the adverse effects of
salt on blood pressure, reduce the risk of developing kidney stones,
and possibly decrease bone loss." The implications of that statement
for the general population were that most individuals should increase
their intake of foods rich in potassium.
Dr. Appel noted that because current intake of potassium was
substantially less than the recommended level, it might be reasonable
to set interim goals that were somewhat lower than the adequate
intake. He then opened the floor for discussion.
Dr. Lupton asked if the Subcommittee would recommend supplementation,
since current intake of potassium fell so far short of the goals. Dr.
Appel replied that the benefits for kidney stones and bones were
strongest for potassium from foods and that there was insufficient
research on which to base a recommendation regarding supplements. He
noted that the Subcommittee would recommend research in many areas,
including the effects of different forms of potassium.
Dr. Weaver expressed concern that "lifetime risk" of high blood
pressure was a vague endpoint and that stronger evidence would be
needed to justify a recommendation that would require major changes in
eating patterns. Dr. Appel acknowledged that high blood pressure was
an intermediate variable and that risk of stroke or coronary heart
disease could vary. He suggested that modeling could be done to apply
the estimated change in blood pressure associated with potassium
intake to the change in risk of stroke or coronary heart disease
associated with that change in blood pressure.
Dr. Lupton asked whether there was any subgroup that responded poorly
or not at all to potassium and who may not need to make radical
changes in their diet. Dr. Appel stated that while there were
responders and non-responders in every group, there was insufficient
data to make that distinction.
Dr. Nicklas asked if the Subcommittee had considered an early study on
ethnic differences in urinary excretion of sodium and potassium. Dr.
Appel replied that when the NHANES III data were stratified by
race/ethnicity, African Americans were found to consume less
potassium. He noted that this finding was of particular concern,
because African Americans were more likely to benefit from increased
Dr. Nicklas asked whether information on the sodium/potassium ratio in
foods would be a useful strategy to help consumers make appropriate
choices. Dr. Appel doubted that would be feasible, since public
awareness of the benefits of potassium was limited and food labels did
not always include potassium content.
In response to a question from Dr. Caballero, Dr. Appel acknowledged
that the benefits of potassium for African Americans was an important
public health issue that the Subcommittee would most likely address in
Dr. King noted that in spite of the strong evidence for the benefits
of potassium, the Subcommittee's conclusive statement was somewhat
guarded. She expressed concern that this was inconsistent with the
Committee's charge to make recommendations based on the scientific
evidence. She stated that if the Subcommittee's recommendation was
different from what the evidence would suggest, it should provide a
rationale. Dr. Appel replied that the qualifier was based on practical
rather than scientific considerations. Dr. Weaver noted that the
Subcommittee had recommended a significant increase and that placing
too great an emphasis on potassium could restrict choices of fruits
and vegetables. Dr. Appel stated that the Subcommittee would include a
table of potassium-rich foods. Dr. King emphasized that it takes time
to accomplish goals and that those goals should be stated clearly. Dr.
Camargo suggested tempering the recommendation by citing feasibility
considerations and stating the need for further research.
Dr. King noted that the statement did not address caffeinated
beverages and asked whether they were a good source of potassium. Dr.
Appel replied that tea was a good source of potassium.
Dr. Appel stated that there was extensive evidence regarding the
effect of reduced sodium intake on blood pressure. The IOM had
reviewed ten dose-response studies and three clinical trials, all of
which showed that reduced sodium was associated with a decrease in
blood pressure. The IOM panel focused on dose response relationships
and on identifying indicators that were important from a health
Reviewing the findings of several dose response studies, Dr. Appel
noted that reduced sodium intake was clearly associated with reduced
blood pressure. Blood pressure reduction was greater for hypertensive
individuals than for non-hypertensives, and for African Americans than
for non-African Americans. More significantly, blood pressure
reduction was greater for African Americans, in general, than for
hypertensive individuals, in general. These findings were consistent
Dr. Appel stated that several groups appeared to be more sensitive
to sodium than their counterparts, including middle age and older
adults, African Americans, and individuals with hypertension,
diabetes, and chronic renal insufficiency. He noted that these were
the groups for whom a modified diet would have the greatest impact.
Dr. Appel cited other potential benefits of reduced sodium intake,
including reduced urinary calcium excretion, reduced left-ventricular
mass, and reduced risk of gastric cancer. He noted the need for
clinical trials with hard outcomes for reduced calcium excretion, such
as bone mineral density or osteoporotic fractures.
Dr. Appel acknowledged that some individuals and groups had argued
against reduced sodium intake. Some were concerned about the lack of
clinical trials testing the effects of sodium reduction on clinical
cardiovascular outcomes. Others argued that only those who are
salt-sensitive should reduce their salt intake; that other factors
such as weight, exercise, or potassium were more important in blood
pressure reduction than sodium; and that the effects of sodium
reduction on plasma renin activity, lipids, and insulin resistance
could mitigate its beneficial effects on blood pressure.
The IOM panel defined adequate intake of sodium as 65 mmol per day,
with an upper limit of 100 mmol. Dr. Appel noted that this was
significantly lower than the current median sodium intake of 187 mmol
per day for men and 126 mmol per day for women, according to NHANES
III data. The rationale for the IOM recommendation was to ensure
adequate intake of other important nutrients and to cover sodium sweat
Based on the evidence, the Subcommittee drafted the following
conclusive statement: "The relationship between salt (sodium
chloride) intake and blood pressure is direct and progressive without
an apparent threshold." The implication for the general
population was that individuals should reduce their sodium intake.
Dr. Appel stated that, in view of the substantial gap between
current levels of sodium intake and an adequate intake level, the
practical approach would be to set interim goals, with the eventual
goal being the adequate intake level. He then opened the floor for
Dr. Weaver stated that it was important to keep the qualifier in
this statement because it allowed flexibility and would send a message
that there were options to achieve the goal. Dr. Appel stated that
individuals who followed the DASH diet still had significant reduction
in blood pressure. Dr. Nicklas noted that some aspects of the DASH
diet differed from the proposed food patterns, especially in terms of
Dr. King noted that while the DASH diet appeared to have the
greatest impact for all groups, simply lowering sodium did not seem to
have an impact, except for African Americans. Dr. Appel noted that the
IOM report had stated that African Americans appeared to be more
salt-sensitive, but he expressed concern about setting specific levels
for certain groups. He noted that average sodium intake for most
Americans was well above the recommended level.
Dr. Weaver stated that it would be easier to encourage people to
try to get enough potassium and calcium than to reduce their intake of
sodium, given the current food supply. She also acknowledged that the
Committee could still recommend that industry consider ways to reduce
sodium levels in foods. Dr. Appel replied that it was important to
make recommendations that were consistent with health, while also
recommending changes in the food supply. He noted that it would be
difficult to achieve the upper limit for sodium without reducing the
sodium content in foods.
In response to a question, Dr. Appel stated that while studies had
been done to compare the effect of weight loss on blood pressure
compared to reduced sodium or the DASH diet, the findings were not
statistically significant. Dr. Appel noted that the study did lead to
increased consumption of fruits and vegetables and dairy products,
reduced fat intake, and increased exercise among participants, all of
which were positive outcomes.
Dr. Nicklas asked whether salt sensitivity developed over time and,
if so, whether sodium intake should be reduced in childhood to prevent
high blood pressure. Dr. Appel stated that salt sensitivity was
progressive over time and that blood pressure tracked from childhood
to young adulthood, but there was little direct evidence from
observational studies or clinical trials at those ages.
Dr. Clydesdale asked whether the Subcommittee had considered the
possibility that older adults might compensate for a decreased sense
of smell and taste by adding salt to foods. Dr. Appel stated that
older adults in a large clinical trial sustained reduced sodium levels
over three years, which would suggest that the taste of foods was not
Dr. Lupton asked whether there was any way to discuss the
consequences of hypertension in and of itself. Dr. Appel replied that
this was difficult because most people would not notice the effects of
blood pressure that was within normal ranges. However, he noted no
studies had identified any risk associated with lower blood pressure.
In response to Dr. Camargo, Dr. Appel said he reviewed three
studies that had documented the role of potassium in blunting the
effects of sodium on blood pressure.
Dr. King asked if the Subcommittee had evaluated the potential
interaction of sodium reduction and iodide deficiency. Dr. Appel
stated that the NHANES III data tracked iodide deficiency and that it
was no longer a problem in the U.S. food supply. Dr. King stated that
it would be important to address sources of iodide in the whole diet.
Ms. McMurry noted that the 2000 Dietary Guidelines had stated that a quarter
teaspoon of iodized salt would provide more than half of the
recommended intake for iodide.Dr. King asked whether the Committee
would agree to setting a recommended intake for sodium that might not
be achievable at present. Dr. Appel noted that the Subcommittee had
debated that issue. He felt it was reasonable to set the AI, or 65
mmol, as the ultimate goal, with the upper limit, or 100 mmol, as the
Dr. Bronner asked if the recommended intake would apply to the
entire general population, or if there would be different
recommendations for groups that were more sensitive to sodium, such as
African American hypertensives. After some discussion, she suggested
adding explanatory notes rather than specific recommendations for
different groups. Dr. Appel noted that studies had shown salt
sensitivity to be especially prevalent in non-hypertensive African
Americans. He supported adding language to state that the recommended
levels could be more important for African Americans.
Dr. Kris-Etherton noted that the DASH diet appeared to have a
greater effect in blood pressure than reduced sodium alone. She
suggested that the recommendation should promote an approach that
combined weight control, potassium, sodium, and overall diet. Dr.
Appel agreed that these were all important, but that the benefits of
an overall diet were already addressed under nutrient adequacy.
Dr. Camargo proposed that language drafted by the Ethanol
Subcommittee ("One can achieve X with sodium levels less than Y")
could be used to address the issue of an interim goal.
Dr. Weaver noted that the conclusive statement did not specify a
recommended level of sodium intake. Dr. Dr. King noted that specific
numbers were important for the food industry and for dietary planning
Should the AI for Potassium and Sodium be Calorie Adjusted?
Dr. Appel raised an additional issue, which was the fact that
electrolyte intake varied with calorie intake. He noted that the AI
for potassium and sodium developed by the IOM panel were based on
clinical studies with the DASH diet at 1,600 calories. He suggested
that allowing for increased electrolyte intake at higher energy levels
would be more practical because it would provide greater flexibility
for developing food patterns. Dr. Appel then opened the floor for
In response to a question from Dr. King, Dr. Appel confirmed that
he was proposing to set targets for electrolytes in conjunction with
energy intakes, while acknowledging that lower levels of sodium would
Dr. Weaver clarified that while this approach would acknowledge
that it might be necessary to exceed the goal at some calorie levels,
it was not meant to imply that the goal for sodium intake should be
lower than 65 mmol.
Dr. King noted that some Committee members were reluctant to accept
the AI as the goal for sodium. She asked the Subcommittee to
reconsider the data on sodium and to develop a good recommendation for
the general population that would also address groups that were salt
sensitive, such as African Americans.
Dr. Lupton reminded Committee members that they had agreed to
accept DRI values and noted that several Subcommittees had made
recommendations that would require changes from current patterns of
consumption. Dr. King agreed that the recommendations should not
deviate from the DRI without providing a strong rationale. Dr. Weaver
acknowledged the importance of discussing mitigating factors when
recommendations deviated from the DRI or AI. She noted that vitamin E,
potassium, and sodium were the main nutrients for which current
intakes differed greatly from the DRI.
Dr. Lupton noted that the discussion on trans fats had led to the
need to consider other types of information, including food industry
and public health considerations. Dr. Caballero stated that it was
unlikely that alternative data could be found to support a higher
level of sodium intake, but there were other reasons for the high
level of sodium in the food supply. He stressed the need to consider
the feasibility of making lower sodium foods available.
Dr. King noted that recommendations for the food industry would be
appropriate for this section of the report and that the Subcommittee
should not hesitate to make such recommendations if they were
supported by the science. She thanked the Subcommittee for their work
and adjourned the meeting for lunch.
Dr. King reconvened the meeting and turned the floor over to Dr.
Weaver and the Nutrient Adequacy Subcommittee.
Nutrient Adequacy Subcommittee
Conclusive Statements and Discussion
C. Weaver, Lead
Dr. Weaver stated that the Nutrient Adequacy Subcommittee included
Drs. Bronner, Go, and Nicklas, plus Dr. King, and with additional
assistance from Dr. Lupton. She acknowledged the significant amount of
assistance that USDA staff had provided.
Recommendations for Nutrients and Vitamins
Dr. Weaver stated the Subcommittee's recommendations for nutrients:
"An RDA, or AI when an RDA has not been established, is the
appropriate goal for a nutrient in making nutrient adequacy
recommendations as part of nutritional guidance. The UL for each
nutrient is the appropriate level to consider as the highest level of
usual intake." She noted that the Subcommittee had spent the
most time on nutrients for which this could be a problem.
She then stated the Subcommittee's recommendations for vitamins:
"A number of vitamins are essential in the diet. They are recognized
as necessary for various biochemical functions within the body, and
ongoing low intake levels may result in deficiency symptoms. Dietary
Reference Intake standards for adequacy (RDA or AI) have been
determined for 14 vitamins."
Dr. Weaver noted that after considerable research and discussion,
the Subcommittee had drafted a specific recommendation for vitamin E:
"Intakes are low for all population groups in comparison to
recommendations from the IOM. Proposed food patterns provided 50 to 90
percent of the RDA. This is a reasonable interim goal given that
studies demonstrate no adverse effects of this level of vitamin E."
She then opened the floor for discussion.
Dr. King noted that the proposed food patterns were based on
typical food consumption and asked if the RDA for vitamin E could be
met if consumption patterns were changed. Dr. Weaver replied that this
would require an overly prescriptive diet and that the Subcommittee
felt it would be sufficient to list good choices for sources of
vitamin E. She noted that there was insufficient evidence regarding
the health benefits or bioavailability of supplements and that further
research to justify the RDA would be valuable.
In response to a question from Dr. Appel, Dr. Weaver acknowledged
that the term "interim level" could be misleading, without reference
to an ultimate goal. She clarified that the Subcommittee was accepting
the amount of vitamin E that the proposed food patterns would provide
and was not actually setting an interim goal. Dr. King recommended
that the Subcommittee revise the wording.
Dr. Appel asked why the IOM had set the RDA at such a high level.
Dr. Weaver replied that the RDA was based on the only study available
on this topic. The food supply had changed since that study was
conducted in the 1950s, but the RDA could not be challenged without
additional data. Dr. Nicklas noted that it would be important to
stress the evidence that there were no adverse effects at the proposed
level of intake and to emphasize the need for further research.
Dr. King asked if the food patterns would provide a higher level of
vitamin E after the fats and oils had been changed to increase omega-3
levels and suggested that the Committee revisit this issue in May.
Recommendations for Specific Population Groups
Dr. Weaver stated that the Subcommittee was developing
recommendations regarding vitamins for specific groups, including
vitamin B12 and vitamin D for the elderly. Based on expert
consultation from Dr. Lynn Bailey, the Subcommittee had decided to
adopt the IOM recommendation for folate and not make a conclusive
statement. She turned the floor over to Dr. Go to present the
Subcommittee's recommendations on vitamin B12 and vitamin D for the
Vitamin B12 for the Elderly
Dr. Go presented the Subcommittee's proposed recommendation on
vitamin B12: "Elderly individuals (older than 50 years old)
should consume food fortified with B12 or supplements to meet their
Dr. Go noted that while older adults were consuming enough B12,
blood levels of B12 were low due to reduced absorption. A recent study
had found B12 deficiency in one in twenty adults between the ages of
65 and 74, and in one in ten adults over age 75. Prolonged B12
deficiency could lead to anemia or neurological problems.
Dr. Go noted that the Subcommittee would recommend the crystalline
form of B12, per the advice of Dr. Marianne Johnson. Questions
remained regarding the appropriate dose, because the evidence from
current studies was inconclusive. He then opened the floor for
Responding to a question from Dr. Appel, Dr. Go reviewed the
clinical evidence regarding B12 and older adults.
Dr. King asked if reduced absorption had been the basis for the IOM
recommendation of B12 supplementation for older adults and whether
there were any clinical consequences of low levels of B12. Dr. Go
confirmed that the IOM recommendation had been based on reduced
absorption. He stated that there were no clinical measures to
determine the levels or point in time at which signs of B12 deficiency
would appear. Dr. Lupton clarified that the RDA for B12 was the same
for all adults, but supplementation was recommended for older adults
because they cannot absorb B12 from food. Dr. Go stated that newer
data supported the IOM report.
Dr. King noted that older adults could meet this recommendation by
eating foods fortified with B-12.
Vitamin D for the Elderly
Dr. Weaver noted that the Subcommittee had challenged the IOM
report based on recent data that was more consistent with the recent
NIH consensus conference. The Subcommittee's proposed recommendation
stated: "Adequate vitamin D status, which depends on dietary
intake and cutaneous synthesis, is important for optimal calcium
absorption and can reduce the risk for bone loss. For the elderly, a
vitamin D supplement containing 10 ug (400 IU) plus 2-3 cups of
vitamin D fortified milk or equivalent is recommended."
Dr. Weaver stated that serum 25 hydroxy Vitamin D levels were the
indicator for Vitamin D status. The elderly had reduced ability to
synthesize cutaneous Vitamin D, for reasons that were not well
understood. She summarized several dose response studies regarding
intake of Vitamin D.
Dr. Weaver noted that fortified and natural dietary sources of
vitamin D were limited and that there were few pharmacological choices
for stand-alone vitamin D. This could be an area for recommendations
to industry. She then opened the floor for discussion.
Dr. Nicklas asked whether calcium supplements that include vitamin
D would be a good source. Dr. Weaver replied that it would depend on
the bioavailability of the supplement, and she noted that individuals
who met their calcium requirement through food would not necessarily
take a calcium supplement.
In response to a question, Dr. Weaver stated that the Subcommittee
had not yet defined the elderly for this recommendation, though
studies suggested that it would be older than 50 years of age. She
noted that there was no consensus for determining age in the
literature and that the studies that were available had sampling
problems. Dr. King stressed that the Subcommittee's statement should
be consistent with other recommendations.
Dr. King asked whether the NIH meeting had identified any other
groups that were at risk for vitamin D deficiency. Dr. Weaver replied
that dark-skinned women of childbearing age and individuals with
limited exposure to the sun could be at risk. She noted that while
vitamin D was important for pregnant and lactating women in order to
ensure adequate levels for the infant, there was insufficient data to
make a dietary recommendation. There was also insufficient data to
make a recommendation regarding vitamin D in chronically ill patients.
Dr. Weaver stated that there were emerging data regarding other
health benefits of vitamin D. The Subcommittee would prepare a table
of vitamin D related studies that had become available since the IOM
Dr. Weaver presented the Subcommittee's recommendations for
minerals: "A number of minerals are essential in the diet. They
are recognized as necessary for various biochemical functions within
the body, and ongoing low intake levels may result in deficiency
symptoms. Dietary Reference Intake standards for adequacy (RDA or AI)
have been determined for 12 minerals."
Dr. Lupton noted, and Dr. Weaver agreed that, suboptimal health
might be a more relevant endpoint for low intake levels than
Dr. Weaver acknowledged that potassium and calcium were the
minerals that presented specific issues. She stated that the
Subcommittee would incorporate the Fluid and Electrolyte
Subcommittee's statements on potassium.
The Subcommittee was still working on a consensus statement and
evidence table regarding calcium and dairy products bone health, which
would be ready for the next meeting. Dr. Weaver noted that the
Subcommittee considered calcium and dairy together because both had
been associated with bone health, and dairy products were the source
of calcium in many studies. The Subcommittee would accept the IOM
recommendation for intake of calcium. Dr. Bronner was examining
lifecycle issues, with a focus on the implications of calcium and
dairy intake in youth for bone health in later life. The Subcommittee
was also examining current intakes by age and gender subgroups and the
sources of calcium for those subgroups to determine what types of
foods would be needed to meet the recommended intake. Dr. Weaver noted
that it was impossible for the food databases to remain current with
regard to the calcium content of fortified foods.
Dr. Kris-Etherton asked what the magnesium levels were in the
proposed food patterns and whether the Subcommittee had reviewed the
literature in that area. Dr. Weaver replied that the food patterns met
the IOM recommended intakes for magnesium and that a literature review
would only be warranted if the food patterns showed a deficiency.
Responding to a question from Dr. King, Dr. Weaver stated that the
proposed food patterns met the requirements for iron in vegetarians,
but that the Subcommittee was still reviewing the general issue of
food patterns for vegetarians.
Responding to a question from Dr. Nicklas, Dr. Weaver stated that
the Subcommittee would prepare a table showing non-dairy sources of
calcium for individuals who were lactose intolerant as well as a list
of low-lactose dairy foods.
Dr. Weaver presented the Subcommittee's two statements on this
- "Food patterns based on commonly consumed foods with proportions
and amounts altered to meet nutrient goals provide nutritional
guidance that is realistic and practical for consumers."
- "Food patterns used in nutritional guidance that are flexible
rather than prescriptive allow for individual choices in making food
selections for nutrient adequacy."
Dr. Weaver stated that the Subcommittee started with the food
patterns proposed in the Federal Register and analyzed the
proportions of commonly consumed foods in each food group. To address
concerns about flexibility, the Subcommittee asked USDA to develop
special iterations of the food patterns to examine the impact of whole
versus enriched grains and fruits versus juices, to develop vegetarian
and lactose-free options, and to identify alternative sources of
nutrients provided by legumes. Other Subcommittees requested
iterations to look at the impact of fat and other variables.
Dr. Weaver summarized the Subcommittee's recommended options to
meet the nutrients provided by enriched grains in the current food
patterns, which it had presented at the January meeting. She noted
that the Subcommittee was still developing vegetarian and lactose-free
options. She then presented the Subcommittee's recommendations
pertaining to fruit juices versus whole fruits and alternatives to
Fruits and Juices
After reviewing the models developed by USDA, the Subcommittee
recommended that no more than 1/3 of the total servings of fruit
should be from juice and no less than 2/3 should be whole fruits. Dr.
Weaver noted that whole fruits were important sources of fiber and
vitamin E, and juices provided folate and potassium. She then opened
the floor for questions.
Dr. Clydesdale noted that, unlike whole fruits, juices were readily
available and the quality was consistently high. Dr. Weaver replied
that "whole fruits" would include frozen and canned varieties and that
the recommendation was intended primarily to address concerns about
consumption of fruit juices.
Responding to a question from Dr. King, Dr. Weaver stated that
current consumption of frozen and canned fruit was very low, compared
to fresh fruit or juice. Some Committee members noted that the variety
of choices was more limited with frozen and canned fruits.
Dr. King asked whether there was strong evidence that excessive
intake of juices was associated with higher BMI or other health
problems. Dr. Weaver noted that juices were an important source of
folate and potassium. Dr. Nicklas stated that the evidence was strong
enough to lead the American Academy of Pediatricians to recommend that
juices be avoided. Dr. King suggested adding a reference to the AAP
Dr. Weaver stated that each half-cup of legumes in the proposed
food patterns could be replaced by either two ounces of whole grains
minus one-half ounce of enriched grains; or 1½
cups of dark-green vegetables; or two cups of other vegetables.
In response to questions, Dr. Weaver noted that the vegetables used
to replace legumes would be in addition to those already included in
the food patterns. She also noted that the proposed alternatives
provided equivalent levels of all nutrients provided by legumes,
Dr. Lupton noted that it would be important to consider amino acid
profiles when developing vegetarian food patterns.
Food Patterns and Flexibility
Dr. Weaver presented the Subcommittee's proposed statement regarding
nuts, seeds, and legumes: "Nuts, seeds, and legumes are rich sources
of trace nutrients, including vitamin E, fiber, and phytonutrients.
However, no required nutrient is unique to these foods. Increased
consumption is recommended as part of the existing food groups rather
than as a separate group, to maintain flexibility in food choices for
Dr. Weaver stated that the Subcommittee was concerned that creating
a separate category for nuts, seeds, and legumes would appear to
reduce the amount of vegetables that were recommended and would
eliminate vegetarian sources of protein from the meat group.
Dr. Clydesdale proposed changing the term "phytonutrients" to
Dr. Weaver presented the Subcommittee's proposed recommendation
regarding whole grains: "Food patterns with at least half of all
grains as whole grains can meet nutrient adequacy goals for dietary
fiber and other nutrients." She noted that the Subcommittee had
debated whether to state the recommendation in terms of half of a
total amount, or to specify a number of servings.
Dr. Lupton stated that she would review the dose-response
literature in this area.
Issues Still Being Reviewed
Dr. Weaver stated that the Subcommittee was still reviewing a
number of issues, including: nutrient density and statements regarding
vitamin E, vitamin B12, folate, vitamin D, calcium, and potassium. She
asked Dr. Nicklas to report on the status of her work on nutrient
Dr. Nicklas cited evidence suggesting that consumption of low
nutrient-dense, high energy-dense foods could displace nutrient-dense
foods and could place individuals at risk of high-energy intake and
marginal micronutrient intake. There was little evidence associating
low nutrient-dense foods with BMI. Dr. Nicklas noted that there were
no large, randomized clinical trials or controlled-feeding studies
regarding energy density. Based on the findings of short-term studies,
Dr. Nicklas stated that it would be reasonable to conclude that
low-nutrient dense foods could be consumed if they did not displace
needed nutrients and they did not exceed available calories.
Dr. Nicklas stated that she would like to address the importance of
variety in dietary patterns. She suggested this could be accomplished
by stating that while there were currently no criteria to distinguish
between low- and high nutrient-dense foods relative to caloric
content, eating a variety of foods from all of the major food groups
would be an initial strategy for ensuring nutrient adequacy. She noted
that the Subcommittee's analysis of the nutrient contributions of each
food group clearly demonstrated the importance of getting foods from
all five food groups.
Dr. Kris-Etherton asked about the relative contribution of each
food group and expressed concern about the potential hazards of
popular diets that eliminated one or more food groups. Dr. Weaver
referred her to the table in the notebook that illustrated the
nutrient contribution of each food group. Dr. Nicklas noted that the
Subcommittee's analysis found that each food group was a major
contributor of at least one nutrient.
Dr. King requested that the Subcommittee's report include a clear
description of the methods used to develop the proposed food patterns
and a discussion of the number of calories that would be associated
with the recommended intake of nutrients within each pattern. She
noted the diversity of the U.S. population and requested that the
Subcommittee refer to cultural influences on eating patterns in its
discussion of alternatives to meet nutrient adequacy.
Dr. Weaver acknowledged the expert advice provided by Dr. Lynn
Bailey regarding folate supplementation in pregnancy and
pre-pregnancy; Dr. Suzanne Murphy regarding use of RDA versus EAR; and
Dr. Maret Traber regarding vitamin E.
Dr. King thanked the Subcommittee for its presentation and
adjourned the meeting for a brief break.
(Break, 2:40-3:00 p.m.)
Food Safety Subcommittee
Conclusive Statements and Discussion
F. Clydesdale, Lead
Dr. King turned the floor over to Dr. Clydesdale and the Food
Safety Subcommittee. Dr. Clydesdale noted that Subcommittee members
included Drs. Camargo and Weaver and acknowledged the support of staff
from USDA and HHS. He stated that the Subcommittee had drafted
recommendations to keep food safe from bacteria and advice on
methylmercury in fish.
Keep Food Safe from Bacteria
Citing recent data on illnesses, hospitalizations, and deaths due
to foodborne diseases, Dr. Clydesdale stated that the Subcommittee
would retain the four basic "FightBAC!" messages
(clean — separate — cook — chill). He noted that "FightBAC!" was a campaign
of the partnership for food safety education created by the USDA, HHS,
the Department of Education, and ten food industry organizations. The
"FightBAC!" messages were developed from a consensus of food safety
experts and had been tested for consumer comprehension.
Dr. Clydesdale noted that the Subcommittee had reviewed the
literature published since the 2000 Dietary Guidelines and consulted with
experts to identify which consumer behaviors posed the greatest risk
of foodborne disease and whether any of those behaviors should receive
greater emphasis in this edition. Based on this background work, the
Subcommittee proposed a number of additions to the guidance in the
- Increase the emphasis on the "chill" step and clarify that this
step applies at any stage of food handling where raw foods are not
being cleaned or cooked. Dr. Clydesdale noted that the Subcommittee
would retain the existing graphic for temperature control.
- Emphasize the importance of cleaning refrigerators to avoid
cross-contamination of foods.
- Add a detailed hand-washing protocol as recommended by the CDC,
and add to the protocol guidance regarding drying hands using a
clean disposable or cloth towel.
- Emphasize that potentially unsafe food should be discarded
without tasting, even if it looks and smells fine. Dr. Clydesdale
noted that the Subcommittee had developed a list of criteria
specifying how long food should stay in the refrigerator and how it
should be washed.
- Add a protocol for washing fresh fruit and vegetables.
- Expand guidance for those at high risk of foodborne illness,
- Add guidance on pasteurized eggs.
- Add a separate message on listeria, including a list of
high-risk foods. Dr. Clydesdale noted that while quite rare,
listeria was fatal, particularly for pregnant women, young children,
and the elderly.
Dr. Clydesdale noted that the Subcommittee would add a
recommendation to not wash meat and poultry if it could find evidence
to support that recommendation. A recent qualitative study conducted
by the "FightBAC!" partnership found that failure to follow this
recommendation was the most dangerous consumer behavior in terms of
risk of cross-contamination. The Subcommittee had been unable to find
any studies demonstrating that washing meat and poultry actually led
to cross-contamination, but it was continuing to search for a
Dr. Clydesdale stated that the Subcommittee would adopt the FDA's
advice regarding methylmercury in fish. Its recommendation would
state: "Women who may become pregnant, pregnant women, nursing
mothers, and young children should eat fish and shellfish lower in
The Subcommittee's recommendation would include detailed advice
regarding the types of fish that should be avoided and those that were
safe to consume as well as guidance pertaining to the safety of fish
caught in local lakes, rivers and coastal areas.
Dr. Clydesdale suggested, and Dr. Kris-Etherton agreed, that this
recommendation should be referenced in the section on fatty acids.
Questions Still Being Reviewed
Dr. Clydesdale stated that the Subcommittee was reviewing the
literature to find data that would support a recommendation not to
wash meat and poultry.
The Subcommittee was also considering whether to include a negative
statement on mad cow disease. Dr. Clydesdale acknowledged that it
could be necessary to reference this issue, but the risk should be
kept in perspective. He asked for the Committee's input on this issue.
After some discussion, Committee members generally agreed that it
would be appropriate to mention mad cow disease in the context of a
scientific discussion of foodborne diseases in the technical document,
but that it should not be emphasized in the public health guidelines.
Dr. Clydesdale reported that in order to put mad cow disease into
context, all potential dangers such as dioxins and acrylamide, would
need to be referenced. Committee members agreed that since these
dangers were uncontrollable by consumers' day-by-day actions, mad cow
disease shouldn't be mentioned at all. Furthermore, Dr. Clydesdale
pointed out that the list of such concerns is so large it would be
impractical to include in the report.
Dr. Clydesdale acknowledged the contributions of Dr. Michael
Patrick Doyle of the University of Georgia, Dr. Lydia Medeiros of Ohio
State University, and Dr. Isabel Walls of the International Life
Dr. King thanked the Subcommittee for its presentation and turned
the floor over to Dr. Camargo and the Ethanol Subcommittee.
C. Camargo, Lead
Dr. Camargo stated that the Subcommittee members included Drs.
Appel and Kris-Etherton and he acknowledged the support provided by
staff. He presented the Subcommittee's conclusive statement on
ethanol: "If you choose to drink, do so in moderation: consumption of
up to one drink a day for women and two drinks a day for men." Dr. Camargo noted that this statement acknowledged the fact that many
people choose not to drink, while also providing a quantitative
definition of the term "moderation." The Subcommittee would accept the
definition of what constituted one drink that appeared in the previous
The Subcommittee's recommendations would also differentiate between
people who should not drink and situations where alcohol should be
avoided. People who should not drink would include individuals who
cannot restrict their drinking to moderate levels; children and
adolescents; individuals taking prescription or over-the-counter
medications that can interact with alcohol; and individuals with
special medical conditions, such as liver disease. Situations where
alcohol should be avoided would include women who may become or who
are pregnant; women who are breastfeeding; and individuals who plan to
drive, operate machinery, or take part in other activities that
require attention, skill, or coordination.
Dr. Camargo stated that the rationale for the Subcommittee's
statement was consistent with evidence from numerous studies that the
risk of all-cause mortality declined with a low level of alcohol
consumption and increased at higher levels of consumption. He noted
that while the exact amounts of alcohol associated with reduced risk
was debatable, the Subcommittee's proposed definition of one drink for
women and two drinks for men was within that range.
Dr. Camargo presented a number of scientific conclusions pertaining
to moderate drinking, based on the studies that the Subcommittee
- Moderate levels of alcohol consumption did not increase risk for
myocardial infarction or ischemic stroke and may have a protective
effect. Dr. Camargo noted that this benefit was primarily important
for older adults.
- There was no evidence that cognitive functioning was negatively
affected by moderate alcohol consumption as one ages, and moderate
levels were not associated with increased risk of dementia.
- Compared to non-drinkers, there was a slight increase in risk of
breast cancer for women who consumed an average of one drink per
- Animal studies suggested that low-to-moderate drinking during
pregnancy could have subtle behavioral or neurocognitive
consequences. Heavy drinking during pregnancy could produce a range
of behavioral and psychosocial problems, malformations, and mental
retardation in the offspring.
- Alcohol ingestion by nursing mothers did not enhance lactational
performance, and could actually decrease it.
- There was no evidence to associate moderate drinking with macro-
or micronutrient deficiencies.
- There was no apparent association between moderate alcohol
consumption and weight gain or obesity.
Dr. Camargo stated that the Subcommittee was still gathering data
on the caloric content of alcoholic beverages, which was not reflected
in the current literature. He noted that the Subcommittee felt it was
important to provide that information, especially with the focus on
Dr. Camargo thanked the National Institute on Alcohol Abuse and
Alcoholism, USDA, and HHS for their support and opened the floor for
Dr. Caballero noted that physical activity could be accumulated
over several days and asked whether the effects of alcohol were
similar. Dr. Camargo replied that greater benefits were associated
with more regular consumption. He stressed that the Subcommittee did
not wish to encourage binge drinking and would specifically counsel,
as the previous Guidelines did, against consuming many drinks at a
Dr. Pi-Sunyer asked if the Subcommittee planned to address binge
drinking among young adults. Dr. Camargo stated that the Subcommittee
would emphasize the risks of heavy drinking in its discussion and
might encourage the types of public policy initiatives that had been
discussed at the January meeting. He stressed that the Guidelines
presented a unique opportunity to educate Americans about moderate
Dr. King asked if the observed benefits were attributed to specific
types of beverages. Dr. Camargo stated that there were no substantial
differences between types of beverages, other than calories. He noted
that hydration was not a concern at lower levels of consumption.
Dr. Appel noted that there seemed to be a cluster of issues related
to special groups, such as pregnant women or older adults. Dr. Camargo
suggested that the report could include a special table of contents or
index highlighting the relevant guidance for various groups.
In response to a question, Dr. Camargo stated that there was
insufficient data to include a discussion of the effects of alcohol on
brain atrophy. He noted that current literature suggested a benefit of
moderate alcohol consumption against risk of dementia and cognitive
function. He suggested that that these were important areas for
further study and that higher-level epidemiological research or animal
models would be useful approaches for studying the effects of alcohol
on brain functioning.
Dr. King thanked the Subcommittee for its good work and agreed that
a table on the caloric value of different types of drinks would be a
valuable addition to the report. She then turned to a review of the
meeting and next steps.
Review of the Meeting and Next
Dr. King turned the Committee's attention to issues to be
considered for the full report. She proposed the following structure
for the report:
- Technical Reviews
- Translation of Technical Reviews into Food-based Guidelines
- Research Recommendations
Dr. King noted that Dr. Suitor had drafted an introduction to the
report that would include the purpose of and legislative mandate for
the Advisory Committee, the reasons for concern about diet, and the
uses of the Guidelines.
The methodology section would describe how the Committee members
were appointed, how the Committee conducted its business, and the
structure of its working groups, as well as a discussion of the
process that the Committee had used to review and summarize the
scientific evidence on which its conclusions and recommendations were
based. It would also include a description of the modeling process
that was used by several of the subcommittees to assist them in making
The technical section of the report would present the conclusive
statements and rationales for those statements developed by each
Subcommittee. It would include data on nutrient intake and food
sources, plus a number of tables and charts.
Dr. King and other Committee members expressed concern about the
amount of work that remained to be done to complete the literature
reviews, revise existing conclusive statements and, in some cases,
draft new conclusive statements. This led to a discussion of whether
the next iteration of the Subcommittee reports should be drafted by
Committee members or by staff. Dr. King proposed that the first
priority should be to address revisions to existing conclusive
statements. She suggested that it would be helpful to have a list of
the conclusive statements based on full literature reviews that still
needed to be done.
The Macronutrient Subcommittee stated that it would hold a
conference call the week of April 5 to determine how to address the
issue of discretionary calories. Dr. Camargo offered to draft a
statement on calories in alcoholic beverages that could be included in
the discussion on discretionary calories and referenced in the ethanol
A question was raised regarding how to approach "sidebar" issues
that were important to address but did not merit conclusive
statements. Committee members suggested that these issues could be
addressed as short paragraphs or footnotes in the conclusive
statements and that pertinent information could be used in the
One Committee member noted that the Subcommittees' conclusive
statements were in different formats and suggested that it would be
helpful to receive feedback from Dr. Suitor prior to finalizing the
statements. Dr. Suitor stated that Committee members did not need to
worry about the form in which they provided their input and that she
would be responsible for making everything consistent. Dr. Lupton
requested that documents for review be sent in MS Word. Dr. Camargo
suggested that posting files on the Internet for download would be
preferable to sending large e-mail attachments.
Returning to a discussion of the outline, Dr. King reminded the
Committee that the translation section would have four major headings,
as discussed the previous day: nutrient adequacy; energy balance;
dietary and lifestyle choices; and food safety. She noted that the
more clearly the technical section was written, the easier it would be
to prepare this section of the report. Dr. Suitor would prepare the
first draft of this chapter, with assistance from Dr. King and input
from Committee members. Ms. McMurry noted that HHS and USDA would
engage one or more contractors to begin looking at existing research
on consumer messages, so that it would be ready to begin drafting
consumer messages by the time the Committee submitted its report.
The last section of the report would be future research
recommendations, cross-cutting issues, data gaps, emerging issues, and
concerns regarding the food industry or nutrition policy. Dr. King
asked each Subcommittee to develop a list of issues and
recommendations that could be combined at the May meeting. Ms. McMurry
advised the Committee that any policy-related concerns should be
worded in terms of general intentions as opposed to specific actions
to be undertaken by specific agencies.
Dr. King proposed that the technical report include a glossary to
assist practitioners in the field who would be involved in translating
the report into food-based recommendations. She asked each
Subcommittee to submit a list of terms to Dr. Suitor, who would
prepare an initial draft. A number of Committee members questioned
whether a glossary was necessary or feasible. Several noted that
studies in some fields, such as carbohydrates, used different
definitions for similar terms. After considerable discussion, Dr. King
agreed that the glossary could wait until the conclusive statements
and the body of the report had been drafted.
The Committee agreed on the following timetable for remaining
- Revisions to existing conclusive statements: Submitted to
Dr. Suitor by April 9
- Drafts of new conclusive statements: Submitted to Dr.
Suitor by April 16
- All conclusive statements finalized: April 30
- Conclusive statements distributed for internal review:
First two weeks in May
- First draft of the full report (including translation
section and all conclusive statements): May 20
To streamline the process, Dr. King suggested that the Subcommittee
chairs should first discuss outstanding issues with staff, and then
with Subcommittee members. She noted that each Subcommittee's section
should be reviewed by at least one Committee member who was not a
member of that Subcommittee. She granted the Nutrient Adequacy
Subcommittee an additional week to submit its conclusive statements
and offered to assist the Subcommittee on some issues.
Dr. Camargo asked if the technical report would include a summary
of public comments. Ms. McMurry stated that staff members were
preparing a summary that would be included as an appendix to the
report. They would aim to complete the summary by the May meeting so
that the Subcommittee chairs could ensure that they had addressed all
Dr. King thanked the Committee and staff for a productive meeting
and acknowledged the Committee's significant accomplishments to date.
She adjourned the meeting at 4:42 p.m.
2005 Guidelines Page