Redemption For The Atkins Diet?

by Jennifer Wider, M.D.

New research suggests that the highly controversial and often criticized Atkins diet may prove to be a viable option for people struggling with obesity. Two new studies in the May 22, 2003 issue of the New England Journal of Medicine reveal that patients on a low-carbohydrate diet lost more weight than those on traditional diet plans. The first study conducted by Gary Foster, PhD and colleagues set out to determine the efficacy of a low-carbohydrate diet and the second study by Frederick Samaha, MD and colleagues compared a low-carbohydrate diet with a low-fat diet in obese individuals. The Foster, et al. study even suggested that people on a low-carbohydrate, high-protein and high-fat diet, the cornerstone of the Atkins diet, showed improvement in some risk factors for heart disease.

Foster and colleagues conducted a clinical controlled trial with 63 obese men and women in an attempt to analyze the effectiveness of a low-carbohydrate, high fat diet. Participants were randomly assigned to two different diet plans: a high-fat, high-protein, low-carbohydrate diet or a more conventional low-calorie, high-carbohydrate, low-fat diet. In addition to a greater weight loss, people on the low-carbohydrate diet had greater increases in their high-density lipoprotein cholesterol (HDL) concentrations and larger decreases in their triglyceride concentrations, both of which can be beneficial in reducing the risk of heart disease.

A diagnosis of high cholesterol usually refers to a person's total blood cholesterol. Fat and cholesterol travel in the blood stream in different forms. High levels of low-density lipoproteins (LDLs or "bad cholesterol") and triglycerides cause plaque build-up in the arteries. High-density lipoproteins (HDLs or "good cholesterol") remove the buildup from the lining of the artery and can protect against heart disease. Therefore, a high level of HDL is desirable.

It seems counterintuitive that consuming high-fat foods could lead to significant weight loss and a decrease in cholesterol, but these findings do not come as a surprise to some nutrition experts. Samuel Klein MD, one of the researchers involved with the Foster, et al. study and Professor of Medicine and Nutritional Science at Washington University School of Medicine in St. Louis explains: "It has been established that when you reduce carbohydrates in the diet, there is a decrease in triglycerides and an increase in HDLs, the two go together." Therefore, a person on a low-carbohydrate diet may experience an improvement of several heart disease risk factors.

Participants on both diet plans also experienced a notable decrease in diastolic blood pressure. According to Dr. Klein, this finding can be directly attributed to weight loss; "the more weight a person loses, the more favorable the change in blood pressure." Although the low-carbohydrate dieters experienced a greater weight loss in the study, the key to blood pressure control is maintaining a normal weight.

In the Samaha, et al. study, researchers used a randomized controlled trial to compare a low-carbohydrate diet with a low-fat diet in severely obese people for six months. This study yielded similar results with low-carbohydrate dieters losing more weight than the low-fat, low-calorie dieters. In addition, participants on the low-carbohydrate diet experienced similar decreases in their triglyceride levels.

Before the public fills their plate with burgers, bacon, butter and cheese, however, the researchers warn that their findings should be interpreted with discretion. The sample populations of both studies were relatively small; larger and longer duration studies are necessary to properly determine the long-term effects of a low-carbohydrate, high-protein, high-fat diet regimen. In addition, there may be sex differences in the response to different diets. According to Dr. Klein, researchers would need a larger study to evaluate these variations.

The Society for Women's Health Research is the nation's only not-for-profit organization whose sole mission is to improve the health of women through research. Founded in 1990, the Society brought to national attention the need for the appropriate inclusion of women in major medical research studies and the resulting need for more information about conditions affecting women. The Society advocates increased funding for research on women's health, encourages the study of sex differences that may affect the prevention, diagnosis and treatment of disease, and promotes the inclusion of women in medical research studies. Dr. Donnica Moore has been a member of the Society since 1990 and is a past member of its Board of Directors.

Created: 6/12/2003  -  Jennifer Wider, M.D.