In the present meta-analysis of randomized controlled
trials comparing low-carbohydrate diets with low-fat diets,
we found that both diets were equally effective at reducing
body weight and waist circumference. Both diets reduced
participants’ blood pressures, total to HDL cholesterol
ratios, and total cholesterol, LDL cholesterol, triglycerides,
blood glucose, and serum insulin levels and raised HDL
cholesterol; however, participants on low-carbohydrate
diets had greater increases in HDL cholesterol and greater
decreases in triglycerides but experienced less reduction in
total and LDL cholesterol compared with persons on lowfat
diets. These findings have important clinical and public
health implications. Over the past several decades, low-fat
diets have been recommended to the public for weight loss
primarily because of their beneficial effects on metabolic
risk factors (4). Our study suggests that low-carbohydrate
diets might provide an alternative approach for weight reduction
without worsening metabolic risk factors.