Whey protein may help overweight individuals lose weight and burn more fat, according to a new clinical trial presented April 2 at the Experimental Biology meeting in San Francisco.

During the study, researchers provided whey protein, soy protein or carbohydrate supplements to 90 overweight and obese, but otherwise healthy individuals. Study participants were randomly assigned to one of three treatment groups: 1) 60 grams per day of whey protein, 2) 60 grams per day of soy protein or 3) a control group receiving 60 grams per day of carbohydrate. All participants were instructed to incorporate the supplement into their normal diet.  Body composition and weight were measured weekly. 

The results, presented by USDA researchers, found that individuals who ate supplemental whey protein for six months weighed about 4 pounds less and had about 5 pounds less body fat than individuals who consumed a carbohydrate supplement. The change in body weight was associated with a decrease in body fat without a significant loss in lean body mass. In addition, the whey-protein group lost more inches around the waist than the carbohydrate group.

Body weight was not different between the whey and soy-protein groups. However, the whey group lost more inches around the waist than the soy group.

"The findings of this study add to our knowledge about the health benefits of whey protein," commented David Baer, USDA researcher. "It's noteworthy that people who consumed whey protein daily, without any additional exercise or caloric restriction, still had a smaller waist circumference at the end of the study compared to the other groups."

"While research is still emerging on this topic, the results of this study support existing research, suggesting that whey protein may improve body composition by preserving lean body mass and promoting fat loss," said Joseph O'Donnell, executive director of the California Dairy Research Foundation (CDRF) and chairman of the U.S. Whey Protein Research Consortium. The consortium provided funding for the study.

California Dairy Research Foundation press release