According to a new study from the US Department of Agriculture’s Human Nutrition Research Center, whey protein powder offers an advantage over soy protein powder if you’re trying to drop a few pounds.
Researchers randomly assigned 90 adults- all overweight or obese- to one of three groups. All three groups consumed their normal diet of approximately 2200 calories, but the first group added a protein drink made with whey, the second group added a protein drink made with soy, and the third group added a drink made with carbohydrates.
All three drinks had the same number of calories (200) and all had the same number of grams (52 grams of protein for the first two groups, 52 grams of carbs for the third group.)
At the start of the study, no significant differences existed among the three groups. The average weight of the men was 218 pounds, while the average weight of the women was 190.
At the end of the 23 week study, those drinking the carbohydrate shake had actually gained about 2 pounds, most of it fat. Those drinking the soy protein shake stayed the same.
But those drinking the whey protein drink actually lost a little bit of weight and body fat (about 2 pounds worth!) And while both other groups saw essentially no change in their waist size, the whey protein group actually lost about an inch around their middles!
Interesting, those in the whey protein group actually had significantly lower blood levels of an appetite-stimulating hormone called ghrelin than those in the carb group or the soy group. “(Grehlin) is a hormone that helps regulate food intake”, said David J. Baer, PhD, research physiologist and lead author on the study. “So the higher concentration (of grehlin), the more hungry someone feels. The lower the concentration, the fuller someone feels.”
Interestingly, though no subjects knew which drink they had been assigned, and were not told to change their basic 2200 calorie diet in any specific way, those drinking the whey protein shake on a daily basis wound up gradually consuming less carbohydrates during the course of the study, even though they were eating the same number of total calories per day.
This reduction in carbohydrate intake may have been a contributing factor in their weight loss.
Apparently something about the whey protein powder seemed to make them crave less carbohydrates (a very nice “side” effect!)