Diets with varying proportions of fat, protein, or carbohydrate all confer the same degree and duration of weight loss, according to a New England Journal of Medicine study.

A clinical trial conducted with 800 adults with BMIs between 25 and 40 were randomized to one of four diet groups, with each participant having a caloric deficit of 750 kcal/day relative to baseline. There were diets with high- and low-fat components, high- and average-protein components, and varying degrees of carbohydrate content.

After 2 years, the amount of weight lost was similar among the four groups (most of the loss took place in the first 6 months). Those losing the most weight were those with the best attendance at group meetings.