Whey and casein protein differ in several respects: rates of digestion (whey is fast, casein is slow); amino-acid profiles (whey is rich in branched-chain amino acids, casein is a good source of glutamine); and optimum timing (whey is best taken before and after workouts, casein should be consumed before bedtime). Yet, you probably don’t know that one of them is better for mass-gaining, and the other can assist during a fat-shedding diet.


Researchers at the University of Surrey (Guildford, England) investigated the effects of whey and casein on food intake and resultant feelings of hunger and fullness, and on metabolite and gastrointestinal hormone responses.


They reported that subjects who consumed 48 grams of whey protein and then ate at a buffet meal 90 minutes later ingested considerably less food than when they consumed 48 g of casein protein before the buffet. This appeared to be due to a 60% greater rise in cholecystokinin levels and a 65% greater increase in glucagonlike peptide levels. Whey left the subjects feeling more satisfied. This research suggests that whey may help bodybuilders who are trying to get lean; casein may be better for hardgainers trying to pack on pounds.


The protein you choose between meals can make a difference. When dieting, reach for a whey shake between meals — it may aid you in eating less throughout the day, thus helping you to burn more than you take in. When trying to gain mass, go with casein shakes between meals. They won’t make you feel as full, so that you’ll be able to eat more quality food at meals, which will help you put on more quality muscle mass. No matter the phase you’re in, include whey protein before and after workouts and casein before bedtime.