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A Low-Carbohydrate as Compared with a Low-Fat Diet in Severe Obesity
Samaha, F.F., Iqbal, N., Seshadri, P., et al., "A Low-Carbohydrate as Compared With a Low-Fat Diet in Severe Obesity," The New England Journal of Medicine, 348(21), 2003, pages 2074-2081.
The following information is available at Pub Med and was not written by Atkins professionals.
BACKGROUND: The effects of a carbohydrate-restricted diet on weight loss and risk factors for atherosclerosis have been incompletely assessed.
METHODS: We randomly assigned 132 severely obese subjects (including 77 blacks and 23 women) with a mean body-mass index of 43 and a high prevalence of diabetes (39 percent) or the metabolic syndrome (43 percent) to a carbohydrate-restricted (low-carbohydrate) diet or a calorie- and fat-restricted (low-fat) diet.
RESULTS - Seventy-nine subjects completed the six-month study. An analysis including all subjects, with the last observation carried forward for those who dropped out, showed that subjects on the low-carbohydrate diet lost more weight than those on the low-fat diet (mean [±SD], –5.8±8.6 kg vs. –1.9±4.2 kg; P=0.002) and had greater decreases in triglyceride levels (mean, –20±43 percent vs. –4±31 percent; P=0.001), irrespective of the use or nonuse of hypoglycemic or lipid-lowering medications. Insulin sensitivity, measured only in subjects without diabetes, also improved more among subjects on the low-carbohydrate diet (6±9 percent vs. –3±8 percent, P=0.01). The amount of weight lost (P<0.001) and assignment to the low-carbohydrate diet (P=0.01) were independent predictors of improvement in triglyceride levels and insulin sensitivity.
CONCLUSIONS: Severely obese subjects with a high prevalence of diabetes or the metabolic syndrome lost more weight during six months on a carbohydrate-restricted diet than on a calorie- and fat-restricted diet, with a relative improvement in insulin sensitivity and triglyceride levels, even after adjustment for the amount of weight lost. This finding should be interpreted with caution, given the small magnitude of overall and between-group differences in weight loss in these markedly obese subjects and the short duration of the study. Future studies evaluating long-term cardiovascular outcomes are needed before a carbohydrate-restricted diet can be endorsed.
The following information was written by Atkins professionals.
Severely obese individuals were counseled to either restrict carbohydrate intake to 30 grams per day or less or to reduce fat by 30% as well as calories by 500 calories per day. The low carb group had greater weight loss and greater improvement in triglycerides compared to those instructed to reduce fat and calories. Insulin sensitivity improved more in people with type 2 diabetes following the low carb diet than the low fat diet. These results suggest that a short-term, low carb diet can benefit severely obese individuals, especially those individuals who have type 2 diabetes or the metabolic syndrome.
