Obesity has become a worldwide epidemic and its prevalence continues to increase at a rapid rate in various populations and across all age groups. Obesity poses a major public health challenge since it is a well recognized independent predictor of premature mortality. Moreover, it often coexists with other cardiovascular risk factors, namely, diabetes, dyslipidemia, and hypertension, which further add to the burden of cardiovascular disease. The dramatic increase in the occurrence of overweight and obesity over the past several decades is attributed in part to changes in dietary and lifestyle habits, such as rapidly changing diets, increased availability of high-energy foods, and reduced physical activity of peoples in both developed and developing countries. Insulin resistance is considered the most common underlying abnormality in human obesity and is influenced by genetic and environmental factors, and in particular, changes in diet and physical activity .
Diet plays an important role in the genesis of obesity. Personal choices, advertising, social customs and cultural influences, as well as food availability and pricing all play a role in determining what and how much an individual eats. Very-low-calorie diets and low-carbohydrate diets lead to greater initial weight loss, but long-term results are no better than more moderate calorie-restricted diets. A program using meal replacements appears to lead to weight loss slightly greater than calorie-restricted diets and offers one option to treat obesity. Dietary patterns low in energy density and glycemic index have potential in treating obesity. Various dietary modifications designed to control excess body weight and dyslipidemia have focused on the manipulation of the amount and nature of dietary energy and fat intakes. In recent years, increased attention has shifted toward the role of dietary protein and fiber intake in the management of obesity.
Dietary protein and effects on food intake and body weight
A high-protein diet is often recommended by nutritionists to help lose fat. It should not be confused with low-carb diets such as the Atkins Diet, which are not calorie-controlled and which often contain large amounts of fat.
While adequate protein is required for building skeletal muscle and other tissues, there is ongoing debate regarding the use and necessity of high-protein diets in weight loss. It is claimed to provide the muscle with amino acids required to repair the damage done by heavy lifting in the gym. Protein supplements are often consumed after weight training, as they provide a quick and easily consumable protein source. Alternatively, meat, beans, or other high-protein foods are used. It is worth noting that it is possible to maintain a strict vegan high-protein diet, though due to the lower nutrient density of plant-based foods this requires a larger absolute volume of food compared to a non-vegan diet. Another study, reported in the Journal of Nutrition, showed that a high-protein diet combined with exercise enhanced weight and fat loss and improved blood fat levels. Researchers suggest that higher-protein diets help people better control their appetites and calorie intake.
Ingestion of foods with high protein content is well known to suppress appetite and food intake in humans . Among the three macronutrients (carbohydrate, fat, and protein), protein has the most suppressing effect on food intake. In addition, dietary protein has been shown to induce higher satiating and thermogenic effects and greater weight loss than carbohydrates [15-17]. In a randomized trial in overweight and obese subjects, consumption of high protein (25% of total energy) in fat-reduced diets for 6 months produced greater weight loss and body fat loss, compared to consumption of high carbohydrate (12% of total energy). These effects were not related to changes in fat intake since the amount of dietary fat (30% of total energy) was maintained constant during the intervention. Similarly, in a 4-week randomized dietary intervention trial of male obese hyperinsulinemic subjects, a high protein hypo energetic diet (45% protein, 25% carbohydrates, and 30% fat) also induced greater weight loss and resting energy expenditure, compared to a high carbohydrate hypo energetic diet (12% protein, 25% carbohydrates, and 30% fat).
Reducing caloric intake by 500 kcal/day should result in a 0.45- to 0.9-kg weight loss each week. However, low-carbohydrate, high-protein diets typically produce a 2- to 3-kg weight loss in the first week.
For a higher protein diet, include lean and low-fat sources of protein at every meal as part of a calorie-controlled diet. You should also stock up on ‘smart carbs’ such as fruits, vegetables, and whole grains, along with healthy fats like nuts, seeds, olives, oils, fish, and avocado.
Not all protein is created equal. Be sure to look for protein sources that are nutrient-rich and lower in fat and calories, such as lean meats, beans, soy, and low-fat dairy.
Role of high fiber diet in obesity
Dietary fiber has many functions in diet, one of which may be to aid in energy intake control and reduced risk for development of obesity. The role of dietary fiber in energy intake regulation and obesity development is related to its unique physical and chemical properties that aid in early signals of satiation and enhanced or prolonged signals of satiety. Fiber is important for weight loss because it:
- takes longer to chew and digest making us feel satisfied sooner
- takes up space in our stomach, making us feel full longer
- helps us eat less food and consume fewer total calories
- doesn’t add calories because the body cannot absorb it
- is found in foods naturally low in fat and calories
- interferes with the absorption of fat
- is found in foods that are packed with vitamins and minerals
Epidemiological studies indicate that dietary fiber intake, especially intake of whole grains or cereal fiber, protect against development of obesity. These studies were recently reviewed and summarized. Two cross-sectional studies (including more than 100,000 persons) and four prospective cohort studies (including more than 100,000 persons) indicated a strong negative association between fiber intake and obesity. The cross-sectional studies indicated that men and women with the highest level of fiber consumption have a relative risk for obesity of 0.77 (95% CI, 0.68–0.87) compared to those with the lowest fiber intake level. The prospective cohort studies reported that women and men with the highest level of fiber consumption had lower rates of weight gain and less obesity than those with the lowest level of fiber intake, with relative risks of 0.70 (95% CI, 0.62–0.78). Thus, these studies suggest that high-level fiber consumption reduces risk for gaining weight or developing obesity by approximately 30%.Because these studies include a wide diversity of ethnic/racial groups, they would appear to have wide applicability and strongly suggest that individuals who have higher levels of fiber consumption have lower weights than those with the lowest fiber intakes. Clinical trials initiated over 50 years ago used fiber supplements as an aid to weight loss illustrated that intact apples with their natural fiber were significantly more satiating than fiber-free apple juice, although both test foods provided 60 grams of carbohydrate.
Fiber-rich food is usually satisfying without being calorically dense. Supplementing a normal diet with gel-forming fibres, such as guar gum, leads to an increased satiation probably due to a slower gastric emptying. Recent long-term studies have confirmed the usefulness of viscous fibres as an adjunct to regular dietary treatment of obesity. Apart from a beneficial effect during caloric restriction, dietary fibre may improve some of the metabolic aberrations seen in obesity. Gel-forming fibers are particularly effective in reducing elevated LDL-cholesterol without changing the HDL-fraction. Impaired glucose tolerance or manifest diabetes is also improved. These effects are probably in part associated with the gelling property of the fibre which leads to an increased viscosity of the un-stirred layer thereby delaying the absorption process. Other sources of dietary fibre with a high content of viscous gums, such as oats, have been shown to reduce LDL-cholesterol. Increased intake of viscous fibre leads to a gradual reduction in fasting glucose levels in diabetics. Where as insoluble fibers are considered gut-healthy fiber because they have a laxative effect and add bulk to the diet, helping prevent constipation. These fibers do not dissolve in water, so they pass through the gastrointestinal tract relatively intact, and speed up the passage of food and waste through your gut removing toxic waste from the colon, and balancing acidity in the intestines.
The Recommend Daily Intake (RDI) for dietary fiber is approximately 30g per day.
Most popular, highly processed foods do not supply large quantities of fiber and as a result many of us are getting much less than we should.
Getting enough fiber and protein is important to the health of us all, but is particularly important if we have weight loss goals. As Proteins and Fiber take more time to digest and it takes more energy expenditure to digest them than carbohydrate or fats, additional energy also aids in weight loss. Apart from many other benefits, fiber can help reduce the risk of developing harmful diseases and can help us to successfully achieve long term weight loss where as protein helps protect our muscle content of the body in turn boosting up the metabolism and help reduce your inches.
To lose weight we need to take in fewer calories than our body needs. When this happens, we draw on our fat stores to provide us with the extra energy we require to function properly. In the long term, this means we lose fat – and as a result, the pounds drop off. Quite simply, meal replacement products offer a way to help us control our calorie intake, without having to worry about counting them for two meals a day. Eg: weight management supplement is the perfect meal replacer with only 175kcal, 20gm protein, 4.2gms fiber( high fibre , high fiber content) with herbal extract of Garcinia Cambogia (which helps in weight loss) and vitamins and minerals according to the RDA values per sachet.