Whey protein promotes greater satiety
Why whey protein beats out casein and soy for satisfying hunger
by Jeff S. Volek, Ph.D., R.D.
Protein is known to promote satiety, but not all proteins have the same effect. A recent study compared the effects of different protein sources on markers of appetite. Subjects were fed a 600 kcal breakfast with either 10% or 25% of the meal consisting of whey, casein or soy. When protein was 10% of the breakfast meal (15g whey), whey protein decreased hunger more than soy and casein. At the higher protein intake (37g) of whey, casein or soy, there were no differences. Although not significant, the amount of food consumed three hours after breakfast was lowest after the whey protein breakfast. This amounted to an 8% decrease in energy intake or about 60 kcal less food consumed during the whey compared to the casein trial. The findings suggest that whey protein may have a unique amino acid composition that affects hunger more than other protein sources.