New studies revisit the low-carb diet
27 May 2003
Two new studies comparing weight loss on a low-carbohydrate (Atkins-style diet) with that on a low-fat (‘conventional’) diet lend some support to the low-carbohydrate approach.
The study results were published in the May 22 issue of the New England Journal of Medicine. The first study showed that among a group of severely obese people, those on a low-carbohydrate diet lost more weight over 6 months than did those on a low-fat diet.
Participants in the study had a high prevalence of diabetes and other risk factors for heart and blood vessel (cardiovascular) disease. Those assigned to a low-carbohydrate diet had a greater reduction in blood fat (triglyceride) levels and a greater improvement in insulin sensitivity over 6 months than those assigned to a low-fat diet. (Insulin sensitivity was only measured in the people without diabetes.)
The second study published in the journal compared weight loss with the low-carbohydrate diet with that from the low-fat diet over 12 months in a group of obese people. Those on the low-carbohydrate diet had lost significantly more weight at 6 months than those on a low-fat diet.
However, by 12 months the low-carbohydrate group had regained more weight than the low-fat group, making the difference in weight loss between the 2 groups insignificant at 12 months.
The researchers emphasised that the cardiovascular safety of a low-carbohydrate diet (which also includes unrestricted fat and high protein) and its long-term effectiveness require further investigation in larger and longer-term studies before this type of weight loss diet can be endorsed.
They suggest that, in the meantime, the current results be interpreted with caution.
Last Reviewed: 27 May 2003
- 1. A randomized trial of a low-carbohydrate diet for obesity. NEJM 2003; 348: 2082-90.
