Supplementing with whey protein during dieting may be an effective way to preserve lean tissue. Whey has a high content of leucine and it provides anabolic effects on muscle protein synthesis.
Researchers at the University of Illinois had overweight women participate in a 6-month weight loss program.
The women were given diet plans that included protein intake at the recommended dietary allowance of 0.8g per kilogram of body weight (about 55g of protein for a 150-pound woman).
One group of women received an additional 25g of whey protein two times per day, while the second group received the same amount of a carbohydrate supplement. Both groups consumed 1,400 kcal per day.
After 6 months, the whey protein group lost almost twice as much body weight (-8%) than the carb group (-4.1%).
Researchers then examined changes in the women’s thighs using magnetic resonance imaging. Results revealed greater loss of adipose (fat) tissue in the whey group. As a percentage of the total muscle volume, there was also a greater amount of muscle tissue present in the whey group.
These results indicate that increased protein intake with whey protein supplementation helped maintain muscle relative to changes in body weight and body fat during calorie reduced diets.