Study: Old-Fashioned Diet Theory Holds True

New research in The New England Journal of Medicine supports a long-held but now out-of-fashion theory of dieting: that how much weight you lose depends on how many calories you consume.

WBUR's Abigail Beshkin reports.

The study looked at four diets. Two were higher in protein. Two were higher in carbohydrates. All were heart healthy.

The 811 participants lost about the same amount of weight-- an average of 9 pounds — regardless of which diet they followed.

This may sound obvious. But in recent decades the idea of calories-in-calories-out has been questioned, says Harvard researcher Frank Sacks.

FRANK SACKS: It used to be a mainstream concept that the way to reduce calories is to reduce fat intake, and then of course the whole Atkins approach is to reduce calories by reducing carb intake and what we're finding is, it is just calories.

Sacks also says participants reported equal levels of satisfaction and fullness with all four diets — a finding that surprised researchers.