The 2010 committee tells us to "shift food intake patterns to a more plant-based diet that emphasizes vegetables, cooked dry beans and peas, fruits, whole grains, nuts, and seeds," (5.) while admitting that there is no sound evidence on which to base such advice, as the following two excerpts from the report clearly show:
"Assessing vegetarian eating patterns and their protein content is complex and current methodologies do not capture critical variations. Therefore, investigators’ ability to quantify any possible association with health benefits is limited." (6.)
"Studies of carbohydrates and health outcomes on a macronutrient level are often inconsistent or ambiguous due to inaccurate measures and varying food categorizations and definitions." (7.)
One very large study that tested the kind of diet endorsed by this committee was only "inconsistent" because the outcome did not match the researchers' preconceived expectations. The Women’s Health Initiative Randomized Controlled Dietary Modification Trial (8.) was a huge government study, involving 49,000 women, designed to show the effects of a low-fat diet on health. After eight years, the women who both significantly reduced the amount of fat in their diet and increased their consumption of fruits, vegetables, and grains, had the same rates of breast cancer, colon cancer, strokes, and heart disease as those in the control group who did not make any changes. And although the women were overweight at the start of the study, they also failed to lose any weight.
Many controlled studies have shown low-carb diets to be superior to low-calorie and low-fat diets for heart disease risk markers, to be equal to or better for weight management, and to be vastly superior for blood glucose control and reducing hunger. A sample of some of them follows
A 2008 study from Duke University compared two diets to see which led to greater improvement in blood sugar control. Eighty-four obese volunteers with type 2 diabetes were randomized into either a ketogenic diet with 20 grams of carbs or fewer per day or a diet that was both low on the glycemic index (slowly digested carbohydrates) and reduced in calories with 500 calories per day less than the amount needed for weight maintenance. Of the participants who completed the study, those eating fewer carbohydrates lost more weight and had greater improvements in HDL (good) cholesterol, triglyceride levels, and glycemic control, and 95.2% were able to significantly reduce or eliminate their diabetes medications.
The conclusion from the abstract of the study states, “Lifestyle modification using low carbohydrate interventions is effective for improving and reversing type 2 diabetes.” (9.)
Figure 2, above, shows the results from studies comparing a high-grain diet and two low-glycemic diets to a low-carbohydrate diet. (The second and the fourth bars in the graph look the same in black and white; the fourth bar in each box represents the low-carb diet.) Notice the rise in good cholesterol and the huge drop in triglycerides for the low-carb group, in addition to the improvements in A1c and blood glucose rates. (Note: There are several kinds of LDL particles; a low carb diet has been shown to increase the large, fluffy particles and reduce the small, dense ones; the rise in LDL on low carb diets usually results from an increase in the kind that is not harmful.)
The chart above is from the A to Z Study (Fig 3) from Stanford University. (12.) Lead scientist, Christopher Gardner, a vegetarian, was clearly surprised and dismayed by the results. You can watch his very entertaining video called, "The Battle of the Diets: Is Anyone Winning (At Losing?), on Youtube here: http://www.youtube.com/watch?v=eREuZEdMAVo. Note: The low-carb faction started at 20 grams a day, but were allowed to increase their carbohydrate consumption by 5 grams per day every week after the induction period, which explains the upward trend of the blue line after 6 months. The other dieters continued to eat the same diet for the duration of the study. Also noteworthy: more participants in the low-carb arm of the study stuck with their assigned diet.
Fig. 4. (15.), above, shows weight loss on a very low-carb, ketogenic diet compared to a low-fat diet from a study at the University of Connecticut. Data from Volek et al.
There are many studies with outcomes similar to the ones I have cited here that were excluded from the DGAC report. The DGAC report also fails to mention a recent, meta-analysis, (14.) reported in the American Journal of Clinical Nutrition that reviewed all the available data and found no evidence for concluding that dietary saturated fat is associated with an increased risk of heart or coronary artery disease. The conclusion from the study says: "A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat." You can read about the study here: http://www.ajcn.org/content/early/2010/01/13/ajcn.2009.27725.abstract
Also not discussed are basic science studies demonstrating that the amount of saturated fat in the blood, the presumed cause for concern, is largely determined, not by fat, but by dietary carbohydrate. (15. and 16.)
The DGAC report claims to rely on the USDA's newly created Nutrition Evidence Library (NEL) and cites "strong evidence" that dietary saturated fat increases LDL cholesterol and the risks for heart disease. It should be pointed out that most of the studies included in the "Search Plan and Results" section of the NEL measured saturated fats in the presence of high carbohydrates, while most studies with a low-carbohydrate intake were excluded from consideration. (17.)
Contrary to the impression given by the DGAC, eating a diet high in natural fat is a health risk only when the diet is high in carbohydrates, which provoke the release of insulin, the fat-storage hormone. Insulin inhibits fat burning and leads to obesity and diabetes and many other diseases that have gotten worse since the government first issued its misguided advice. The 2010 committee makes the same mistake that set off the current era of fat-phobia by putting all "solid fats" into one category. Natural fats, which have been staple foods in the diets of healthy populations since prehistoric times, are lumped together with the artificially-hardened fats like hydrogenated shortening and margarine, that have been shown to be detrimental to health.
Fats and proteins are essential to life. Dietary carbohydrates are not. Some carbohydrates contain essential micronutrients, all of which are readily available from low-carb sources, such as green vegetables and low-sugar fruits.
There is a growing body of research that shows that most of the ills that have been blamed on fats are really caused by the excess sugar and starch that replaced them in the American diet. (Starch is quickly converted into sugar in the body.) Diabetes is a condition in which the body’s ability to metabolize carbohydrates is impaired, yet the USDA advises everyone, even those with diabetes, to consume most of their calories as carbohydrates. New research is showing that advice to be, not just counter-intuitive, but part of the problem. It is time to return to the good, natural fats that have been blamed for the mess created by the heavily-promoted, "heart-healthy," low-fat foods and manufactured fats that replaced them.
Harvard professor, Mier Stampfer, who worked on the last food pyramid, said that this year's committee, "knows perfectly well what the evidence says, but they don't want to shake the status quo or risk confusing the public by changing the message," (www.slate.com/id/2248754).
The Dietary Guidelines serve as the cornerstone of Federal nutrition policy and nutrition education activities. They strongly influence education and research funding and they decide the content of the government's meal programs, including food supplied to military personnel, prisoners, and school children. They give direction to the food industry, regulatory agencies, consumer advocates, and the media. The DGAC panel is appointed by the Secretaries of the U. S. Department of Agriculture and of Health and Human Services; they wield tremendous power for a committee that is not elected and answers to no one.
In suggesting the need for an entirely new process, Richard David Feinman, Professor of Cell Biology at SUNY Downstate Medical Center said, “The previous Guidelines have not worked well. It is simply unreasonable to ask the DGAC to audit its own work. An external panel of scientists with no direct ties to nutritional policy would be able to do a more impartial evaluation of the data. This would be far better for everyone.”
A story of two lunchesI recently ate lunch at a Greek restaurant. The gentleman next to me ordered the special—a plate with grilled chicken kebobs, Greek salad, pita bread, and rice. I ordered the same plate, but said "hold the pita and rice." My low-carb lunch had fewer calories, fewer carbohydrates, it provoked less insulin (the fat storage hormone) and it kept me satisfied until dinner. His had the same amount of fat and protein, was higher in calories, higher in carbohydrates, and it must have provoked a significant insulin response. He, no doubt, stored more of his lunch as fat and was probably hungry again an hour later. I ask you, who had the more healthful meal?
(1.) Select Committee on Nutrition and Human Needs of the United States Senate. Dietary goals for the United States. 2nd ed. Washington, DC: US Government Printing Office; 1977.
(2.) US Department of Agriculture and US Department of Health and Human Services. Report of the Dietary Guidelines Advisory Committee on the dietary guidelines for Americans, 2010. June 15, 2010. Available at: http://
(3.) Centers for Disease Control and Prevention (CDC). National Center for Health Statistics, Division of Health Interview Statistics, data from the National Health Interview Survey. Available at: http://www.cdc.gov/diabetes/
(4.) Centers for Disease Control and Prevention (CDC). Trends in intake of energy and macronutrientsdUnited States, 1971–2000. Morb Mortal Wkly Rep 2004;53:80–2. Available at: http://www.cdc.gov/mmwr/preview/
(5.) DAGC report, Part B, Section 3, p.3 (http:// www.cnpp.usda.gov/DGAs2010-DGACReport.htm )
(6.) DAGC report, Part D, Section 4 p. 31 (http:// www.cnpp.usda.gov/DGAs2010-DGACReport.htm )
(7.) DAGC report, Part D, Section 5, p. 43 (http:// www.cnpp.usda.gov/DGAs2010-DGACReport.htm )
(8.) The Women’s Health Initiative Randomized Controlled Dietary Modification Trial, Journal of the American Medical Association, February 8, 2006, Vol. 296 No.
(9.) Westman, E.C.; Yancy, W.S. Jr; Mavropoulos, J.C.; Marquart, M.; McDuffie, J.R.; “The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus,” Nutr Metab (Lond), 2008 Dec 19;36.
(10.) Jenkins DJ, Kendall CW, McKeown-Eyssen G, Josse RG, Silverberg J, Booth GL, et al. Effect of a low-glycemic index or a high-cereal fiber diet on type 2 diabetes: a randomized trial. JAMA 2008;300:2742–53.
(11.) Westman EC, Yancy WS, Mavropoulos JC, Marquart M, McDuffie JR. The effect of a low-carbohydrate ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutr Metab (Lond) 2008;5:36.
(12.) Gardner C, Kiazand A, Alhassan, Kim S, Stafford RS, Balise RR, et al. Weight loss study: a randomized trial among overweight premenopausal women: the A to Z diets for change in weight and related risk factors. Comparison of the Atkins, Zone, Ornish, and LEARN. JAMA 2007;297:969–77.
(13.) Volek JS, Phinney SD, Forsythe CE, Quann EE, Wood RJ, Puglisi MJ, et al. Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids 2009;44:297–309.
(14.) Patty W Siri-Tarino, Qi Sun, Frank B Hu, and Ronald M Krauss Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease, Am J Clin Nutr 2010;91:502–9.
(15.) Volek JS, Fernandez ML, Feinman RD, Phinney SD. Dietary carbohydrate restriction induces a unique metabolic state positively affecting atherogenic dyslipidemia, fatty acid partitioning, and metabolic syndrome. Prog
Lipid Res 2008;47:307–18.
(16.) Forsythe CE, Phinney SD, Fernandez ML, Quann EE, Wood RJ, Bibus DM, et al. Comparison of low fat and low carbohydrate diets on circulating fatty acid composition and markers of inflammation. Lipids 2008;43:65–77.
(17.) http://www.nutritionevidencelibrary.com/template.cfm?template=sort_list_template&key=1023 .
Much of the information above is from an article in Nutrition: A. H. Hite et al. In The Face of Contradictory Evidence: Report of the Dietary Guidelines for Americans Committee, Nutrition 26 (2010) 915–924. Read the entire article here: http://www.sportfuel.com/userfiles/file/hite_dgac_critique_nutrition_2010.pdf