Metabolic advantage is a term used in nutrition to describe the ability of a diet to achieve greater weight loss (or less weight gain[1]) than another diet of equivalent calories.[2] It is a claimed effect of low-carbohydrate diets and was popularised by the Atkins diet, but although several mechanisms exist to make it biologically plausible, it has yet to be definitively demonstrated as a significant factor in weight control. Some studies [3] that have specifically measured the changes in basal metabolic rate under isocaloric very high-fat and very high-carbohydrate diets have failed to find any statistically significant differences.