Understanding the New Atkins Research
By John McDougall MD
Two studies on the Atkins diet - the Samaha and the Foster studies - were published recently (May 22, 2003) in the New England Journal of Medicine. Both showed a greater weight loss (13 pounds at 6 months and 10 pounds at 12 months) on the low-carbohydrate diet compared to the low-fat diet (4 and 6 pounds). The diets labeled as "low-fat," were designed to be 30% and 25% of the calories as fat, respectively - which, at best, could be considered "moderate-fat." In the Samaha study, prior to the intervention, the participants were eating 33% of their calories as fat. So how does decreasing the fat by 3% make this a low-fat diet? Furthermore, when the study was finished, those on a "low-fat" diet were eating 33% of their calories as fat - exactly the same as before the study. Any weight loss from the "low-fat" diet was clearly due to calorie, rather than fat, restriction. A truly low-fat diet as prescribed by Kempner, Pritikin, Ornish and McDougall has 7% to 10% of the calories as fat.
Without a doubt a high-protein, very low-carbohydrate diet causes weight loss, but as these two studies showed, this kind of diet cannot be sustained - nearly half of the participants in the Samaha study did not last 6 months and in the Foster study nearly 40% quit by 12 months. The "low-fat" group did no better - calorie-restricted diets have never worked because it is too painful to be hungry. Furthermore, if the one hospitalization for chest pain and the one death in the Atkins diet group are any indication of the future for people who choose high-fat diets, then clearly people are sacrificing their health for temporary weight loss.
The mechanisms causing weight loss from the low-carbohydrate diets used in these studies should discourage doctors from recommending this approach to their patients. Followers of this diet complain of reduced appetite, nausea, and fatigue - all symptoms of illness. If followed strictly enough to enter ketosis - the goal of the Atkins diet - then there may be actual appetite suppression. Eating less, causes people to take in fewer calories and lose weight. Another result of eating less is they consume less saturated fat, cholesterol, sodium, and animal protein. Signs of improved health seem to appear because risk factors, like serum cholesterol, triglycerides, uric acid, and glucose, and blood pressure, decrease - and the patient is declared healthier. Not necessarily so. Similar benefits, for similar reasons, are seen when patients are placed on cancer chemotherapy - and doctors don't brag about these results.
If people want to know the truth about good nutrition, they simply need to look at the world picture. Populations following high-carbohydrate, low-fat, lower-protein diets, like those from traditional Asian and African countries are trim for a lifetime and avoid all the diseases common to people who follow the Western diet. The Atkins diet is simply an exaggeration of the unhealthy Western diet to a level that makes people sufficiently ill to lose their appetite.
1) Samaha FF. Low-Carbohydrate as Compared with a Low-Fat Diet in Severe Obesity. N Engl J Med. 2003 May 22;348(21):2074-2081.
2) Foster GD. A Randomized Trial of a Low-Carbohydrate Diet for Obesity. N Engl J Med. 2003 May 22;348(21):2082-2090.
3) Subramaniam S. Studies on the changes in plasma lipids and lipoproteins in CMF treated breast cancer patients. Biochem Int. 1991 Aug;24(6):1015-24.
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