Low-Fat Diets Are More Effective Than Cutting Carbs For Weight Loss

New research suggests that a low-fat diet leads to more weight loss than cutting carbs, BBC News reported.

Researchers found that, contrary to popular claims, restricting dietary fat can lead to greater body fat loss than carb restriction, even though a low-carb diet reduces insulin and increases fat burning.

"A lot of people have very strong opinions about what matters for weight loss, and the physiological data upon which those beliefs are based are sometimes lacking," Kevin Hall, researcher at the National Institute of Diabetes and digestive and Kidney Diseases, said in a statement. "I wanted to rigorously test the theory that carbohydrate restriction is particularly effective for losing body fat since this idea has been influencing many people's decisions about their diets."

For the study, researchers recruited 19 adults with obesity. They were confined to a metabolic ward for a pair of 2-week periods, over the course of which their food intake was closely monitored and controlled, The Daily Times Gazette reported.

To keep the variables simple, the two observation periods were like two sides of a balance scale: during the first period, 30 percent of baseline calories were cut through carb restriction alone, while fat intake remained the same. During the second period the conditions were reversed. Each day, the researchers measured how much fat each participant ate and burned and used this information to calculate the rate of body fat loss.

Researchers found that body fat lost with dietary fat restriction was greater compared with carbohydrate restriction, even though more fat was burned with the low-carb diet.

Hall does caution against making sweeping conclusions about how to diet from this study. He told BBC News that for now, the best diet is the one an individual can stick to.

"If it's easier to stick to one diet than another, and to ideally do it permanently, then you should choose that diet," Hall told BBC News. "But if a low-fat diet is better for you, then you are not going to be at a metabolic disadvantage."

The findings are detailed in the journal Cell Metabolism.