Heart Beat

A weight loss "secret": Calories matter

Diet gurus have long promoted weight-loss strategies that fiddle with the form of calories. Avoid fat. Avoid carbs. Eat lots of protein. Balance carbs, fats, and protein. The only thing that really matters, though, is taking in fewer calories than you burn. That's the conclusion from the latest trial comparing weight loss across four popular diet strategies: low fat, average protein; low fat, high protein; high fat, average protein; high fat, high protein. Each diet met the American Heart Association's recommendations for cardiovascular health.

Participants in each group quickly lost weight, then gradually regained some. After two years, weight loss was similar across the four plans, on the order of 7 to 9 pounds. Feelings of hunger, of being satisfied, and of satisfaction with the diet were the same across the board. So were cholesterol levels and other markers of cardiovascular risk (New England Journal of Medicine, Feb. 26, 2009).