my personal edition > obesity > news
E-Mail this DGReview to a colleague
DGReview
Low-Carbohydrate Diet Better Than Low-Fat for Weight Loss, Insulin Sensitivity, and Triglycerides
A DGReview of :"A low-carbohydrate as compared with a low-fat diet in severe obesity"
New England Journal of Medicine (NEJM)
05/29/2003
By Emma Hitt, PhD
In severely obese subjects with diabetes or the metabolic syndrome, a 6-month low carbohydrate diet may increase weight loss and improve insulin sensitivity, and decrease triglyceride levels compared to a low-calorie low-fat diet.
According to Frederick F. Samaha, MD, with the Department of Medicine, Division of Cardiology, University of Pennsylvania Medical Center, Philadelphia, United States, and colleagues, concern exists over whether a low carbohydrate diet adversely affects serum lipid concentrations, and studies on the subject have produced conflicting results.
Dr. Samaha and colleagues randomly assigned 132 severely obese subjects (including 77 blacks and 23 women to a low-carbohydrate diet or a calorie-restricted low-fat diet. Of the participants, 39 and 43% had the metabolic syndrome. Seventy-nine subjects completed the 6-month study.
During the study, the researchers found that subjects lost more weight on the low-carbohydrate diet compared to the calorie-restricted low-fat diet (mean [+/=SD], -5.8 +/=8.6 kg versus -1.9 +/=4.2 kg; p=0.002). The low-carbohydrate group also had greater decreases in triglyceride levels (mean, -20+/=43% versus -4+/=31%; p=0.001). Furthermore, this finding was independent of the use of hypoglycaemic or lipid-lowering medications.
Insulin sensitivity, measured in subjects without diabetes, also improved more among subjects on the low-carbohydrate diet (6+/=9 % versus -3+/=8%, p=0.01). The amount of weight lost (p<0.001) and assignment to the low-carbohydrate diet (p=0.01) independently predicted decreased triglyceride levels and insulin sensitivity.
"These findings must be interpreted with caution however," the authors note, "since the magnitude of the overall weight loss relative to our subjects' severe obesity was small, and it is unclear whether these benefits of a carbohydrate-restricted diet extend beyond 6 months." They add that dietary adherence was relatively low in both diet groups.
"Given the known benefits of fat restriction, future studies evaluating long-term cardiovascular outcomes are needed before a carbohydrate-restricted diet can be endorsed," they conclude.
NEJM 2003 May;348:21:2074-2081.
"A low-carbohydrate as compared with a low-fat diet in severe obesity"
All contents Copyright (c) 1995-2009 Doctor's Guide Publishing Limited. All rights reserved.
| 
