The protein content of a meal influences appetite, satiety (fullness), and caloric expenditure, which is why protein is a critical component in a weight-loss diet. Swiss scientists found that the type of protein in a meal influenced metabolic control.
Whey protein triggered greater post-meal thermogenesis (caloric expenditure) and fat use than soy or casein protein. Whey also reduced the increase in blood sugar following a high-carbohydrate meal, greater than soy or casein protein. However, casein and soy were better at suppressing hunger than whey protein, but test subjects liked the taste of the whey protein supplement better than the other protein sources. Each protein source had its advantages, and these should be considered when designing weight-loss diets and maximizing performance through sports nutrition. (American Journal of Clinical Nutrition, published online January 12, 2011)