New research published in the March/April 2014 issue of the Journal of the American College of Nutrition shows whey protein, either as a supplement combined with resistance exercise or as part of a weight-loss or weight-maintenance diet, may provide men and women benefits related to body composition.
The meta-analysis included 14 randomized controlled trials with a total of 626 adult participants. When researchers analyzed those weight loss studies that used whey protein to replace calories in the diet, participants had a decrease in body weight of 4.2 kg (9.2 pounds), on average, compared to baseline values with whey protein intake. Additionally, after analyzing muscle protein synthesis studies that included resistance exercise along with whey provisions, researchers found that participants had a statistically significant increase in lean body mass of 2.24 kg (4.9 pounds), on average, when whey protein was used in conjunction with resistance exercise.
"There is a growing body of research that supports the benefits of whey protein for weight maintenance and lean body mass," said Dominik D. Alexander, PhD, MSPH, principal investigator. "By conducting this meta-analysis we were able to better evaluate the collective power of each individual study. The results indicate that there is something unique about whey protein, compared to other protein sources and carbohydrates, when it comes to building lean body mass and maintaining or losing weight."
Whey protein is a high-quality protein naturally found in dairy. It is a complete protein containing all of the essential amino acids—the "building blocks"—that the body needs, and is rapidly digestible. Whey protein is also one of the best sources of a subgroup of three essential amino acids, called branched-chain amino acids (BCAAs), which include leucine, isoleucine and valine. Unlike other amino acids, BCAAs are almost exclusively taken up and used by muscle. And, among common food sources of BCAAs, whey protein contains one of the highest levels of leucine, which has been shown to influence muscle growth.
This research is one of several studies supported by the Whey Protein Research Consortium, an international partnership of dairy cooperatives, associations, processors and multinational companies working together to support whey research. The Consortium's first study by Dr. David Baer, USDA, found that daily consumption of whey protein, but not soy protein, led to lower body weight, body fat and waist circumference compared to carbohydrates in free-living overweight and obese adults.
"These research findings support the Consortium's goal to create a strong scientific foundation demonstrating the health and wellness benefits of whey protein," said Bryan Helwig, PhD, Whey Protein Research Consortium. "This research provides further evidence demonstrating the benefits of whey proteins as they relate to body composition," said Dr. Helwig.