Details: A randomized, crossover trial with 28 overweight/obese individuals. Study went on for 30 days (for women) and 50 days (for men) on each diet, that is a very low-carb diet and a low-fat diet. Both diets were calorie restricted.
Weight Loss: The low-carb group lost significantly more weight, especially the men. This was despite the fact that they ended up eating more calories than the low-fat group.
Conclusion: The low-carb group lost more weight. The men on the low-carb diet lost three times as much abdominal fat as the men on the low-fat diet.
JS Volek, et al. Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women. Nutrition & Metabolism (London), 2004.