I just got done reading the book Death by Food Pyramid by Denise Minger. I liked it a lot, and think it’s one of the best health books I’ve ever read.
It talks about a lot of contentious topics in an analytical way with no preference for ideological agendas. It goes fairly deep into the science of nutrition, but in a way that’s always relevant and interesting. You never get the impression she wants to present her opinion as infallible. Just the opposite.
It covers the history of government sanctioned nutrition advice, the popularity of the low-fat high grain diet, and finishes up by synthesizing research on the most important diets and why they work for some people and fail for others. (Paleo, mediterranean, vegan, etc).
The author Denise Minger is an obscure blogger who rose to fame by discovering holes in the data produced by the China Study, which is considered a manifesto for plant based living. While she doesn’t go out of her way to affiliate with any particular way of eating, her work is used as a mascot by people who follow a paleo/low-carb diet since she sucked the air out of the intellectual justification for meatless eating.
The USDA Food Pyramid: Part Nutrition, Part Politics
The book begins with a narrative about the food pyramid and how politics was always getting in the way of the nutrition advice contained within it. It started as a way to revamp the governments public health message about best diet practices but ended in a political bloodbath. Industry groups were paranoid about being classified in the “Do Not Eat” category, so they engaged in an arms race to get themselves pushed further down to the bottom and avoid stigmatization, particularly meat and dairy corporations.
The end result was a pyramid that prioritized political correctness over scientific accuracy.
This passage talks about how the integrity of recommendations gradually eroded:
The guide kept sugar well below 10 percent of total calories…..limited refined carbohydrates…grains were pruned down to a maximum of two to three servings per day.
But then by the time it was finished…..
The guide Light and her team worked so hard to assemble came back a mangled, lopsided perversion of its former self. The recommended grain servings had nearly quadrupled…..dairy mysteriously gained an extra serving…..the cold pressed fats Light’s team embraced were now obsolete. Vegetables and fruits….were initially slashed down to a mere two-to-three servings a day total.
The Rise of the Low-Fat Diet
At the same time the food pyramid began appearing on cereal boxes it became apparent that lots of people were dying from heart attacks and strokes, and getting fat in general.
The new awareness of the problems with overnutrition helped foment two initiatives:
- A scientific one to pinpoint the causes for America’s new diseases
- A political one to trumpet healthy eating and appropriate diet practices based (partly) on the results from initiative 1
In hindsight the practitioners of both these agendas had good intentions, but also jumped to conclusions and got some important ideas wrong.
Politically the lowfat, healthy eating campaign was led by George McGovern, who was inspired by the work of a scientist named Nathan Pritikin, who used population research to come up with the idea that diets high in cholesterol increase your chances of heart disease.
This work was followed up by four studies that gained a lot of political traction in cementing the low-fat, high grain diet into public consciouness.
- The Six Countries Study and Seven Countries Study. Two epidemiological studies that found a strong correlation between countries that didn’t eat a lot of fat and animal products and low rates of heart disease.
- The Finnish Mental Hospital Trial and Oslo Diet-Heart Study. Two clinical studies that examined what happens when you swap out cholesterol and saturated fat for “healthy fats” like olive and canola oil.
The results of these papers suggested that people ought to cut down on saturated fat and animal products and replace them with grains and polyunsaturated fats (PUFA’s).
The studies were interesting, but publicized beyond their merit. According to Minger, by the time their flaws were recognized the message had already been made clear: NO MORE FAT!
Ultimately the problem with all of them is they didn’t control for variables very well. Epidemiology studies are famous for having this problem. Both the Six and Seven countries papers found a correlation between fat, animal products, cholesterol and heart disease, but ultimately failed in narrowing down a cause.
The big problem is that people tend to eat more of all those things as they make more money. But they’re also eating more calories, sugar, and desserts, as well as being more sedentary and sleeping less. So how can you tell which one is causing heart disease? You can’t. At least not from a population study.
The other two studies were more conclusive, but ultimately swapped out a lot more than just fat. Participants in the two groups also differed in the amount of omega-3 fatty acids, sugar, and trans fats they were consuming, not just saturated fat. These studies got publicized the same time industry figured out how to make things like Crisco and trans-fats, both of which are derived from vegetable oils and cheaper than their animal equivalents. Even though both of those have proven to be deadly to our health, big Ag was happy to prop up the low-fat enthusiasts as useful idiots to legitimize their products.
Here I think Denise did a fine job of going into detail on how some of these “studies” work that you always see cited in the news. And maybe more importantly, she helps illustrate how reading them uncritically can leave you with a false sense of security about how much you think you know about this stuff. Bloggers in particular are guilty here, because they usually cherry pick papers with convenient abstracts and don’t pay attention at all to how persuasive the conclusion actually is. They just link-drop to make their opinions seem more credible.
My only quibble is that she didn’t do the same for similar studies done on low-carb diets, and what they do or don’t say about how people ought to eat.
Why Some Diets Work For Some People and Don’t For Others
You’ve probably read how some people in the Mediterranean live a long time. Or you might know a vegan who’s always spraying their Facebook wall with posts about how energetic they feel after ditching animal products. Or maybe you read a book that talked about…….(fill in the blank).
You get the idea.
Diet and health literature can be frustrating by the large variety of options that all seem to work.
The last part of her book deals with how so many different diets can all claim to the way to eat….and have lots of examples to prove their point. Can they all be right, even when they chastise different food groups?
This part of her book was my favorite because she did a great job of synthesizing a lot of really important points about what successful diets have in common and how genetic variation affects what people will have success with them.
What They Have in Common, What They Don’t
Any eating regime that’s endured scrutiny has the following items in common:
- They preach the elimination of processed foods
- They preach the elimination of refined carbohydrates (even guys like Dr. McDougall and Joel Fuhrman who otherwise preach the benefits of a high-carb diet)
- They preach the elimination of heavy alcohol consumption
- They preach the elimination of excess sugar consumption
- They preach the adoption of a variety of other lifestyle habits besides diet (exercise, sleep, strong social bonds, etc)
Obviously, they share a lot in common with what they want to eliminate. (This is an important point. If every single successful diet agrees on eliminating the same things, maybe that by itself is enough to stay in decent health).
But what about the areas in which they differ? If meat is inherently cancerous then how can guys like Atkins have so many people losing weight on his diet?
Ultimately, she suggests it’s not meat itself that’s causing the problem.
Here are the important points to consider:
- The way our meat is processed has a lot to do with its correlation to bad health outcomes.
- For most people being vegetarian means more than just abstaining from meat. It’s a whole new way of life. (More sunshine, exercise, etc).
- No major society has been truly vegetarian (contrary to what guys like Dr. McDougall say).
- The human digestive system does not resemble that of a true herbivore.
- We mostly consume meat muscle, but the most nutritious parts of the animal are its organs.
She finishes up the book by talking about how genetic variations have large impacts on how people digest different macronutrients.
These include but are not limited to:
- Your expression of the amylase enzyme, which affects your ability to digest starch. (People with a low expression of amylase do not digest starch very well).
- Your expression of the ApoE4 gene, which affects your ability to pack away cholesterol and store fat. (These people react badly to high fat diets).
- Your ability to convert vitamin A analogues from plants into the real thing. (People who can’t do this might not do well on vegan diets)
- Your propensity to store iron. (If you store it efficiently lots of meat might be bad for you. Too much iron is not a good thing).
- People differ in their ability to digest lactose and gluten, which will determine how much wheat and dairy you ought to consume.
If you add all this up, it’s entirely possible for many people to have a differing level of success with different diets depending on their own genetic fingerprint.
It’s A Good Book. Go Read It.
Like I said at the beginning of this post, I really enjoyed Death by Food Pyramid and think it’s one of the year’s best books so far. It paints a very nuanced picture of how disparate nuggets of health wisdom can seem to be conflicting but still be true at the same time.
Some of the material I was already familiar with, but much of it was new (particularly her section on Weston Price, which was a joy to read). My only real complaint is that sometimes her narratives seemed more like Ad Hoc storytelling that came off as substantiated truth.
I don’t doubt her journalistic integrity, but the internet has taught me that intelligent people can easily close their own minds by sifting through huge amounts of information that allows them to concoct water tight theories about how the world works……and make it sound really good.
I’d guess that she’d agree with that last statement and don’t think she did any of that by intent. A lot of it might be the result of editorial guidelines. But sometimes I felt like the story of the food pyramid and its consequences required a little bit of cherry-picking for the sake of journalistic flair.
But ultimately these are small quibbles in what was otherwise a delightful book that I’d highly recommend.