Low-carbohydrate diets, obesity, and metabolic risk factors for cardiovascular disease.

Given the increased prevalence of obesity in the United States (and its associated cardiovascular risk) despite reduced fat intake, there has been increasing interest in the effect of low-carbohydrate diets on obesity. Recent prospective trials have demonstrated equivalent weight loss on low-carbohydrate versus low-fat diets, but with significantly different effects on metabolic risk factors for cardiovascular disease. Low-carbohydrate diets have more favorable effects on metabolic abnormalities found in insulin resistance syndromes, including serum triglyceride levels, high-density lipoprotein cholesterol levels, and small, dense low-density lipoprotein particles. The translation of these different metabolic effects on cardiovascular disease and events requires future studies. These studies should take into consideration that patients with insulin resistance syndromes would be the most likely group to benefit from carbohydrate restriction.