Generally about 20-25 grams per day of whey protein is adequate to reap the benefits for body composition, weight management and immunity benefits. Athletes in training or competition may need more, 40-50 grams per day, to replace the proteins burned in exercise and to help repair and build new muscle tissue. Remember that whole food sources of protein such as milk and dairy foods, meat and legumes are still important for the other nutrients that they provide beyond protein.