Answer: Sports Nutrition Editor
Whey has a high branch chain amino acid (BCAA) content, about 50% of the essential amino acids. If you ever go into calorie deficit, your body can burn BCAA's for energy thus sparing hard-earned muscle tissue. Since many people have milk allergies, its popularity has soared even more.
Casein, which is 80% of the protein found in milk, is a type with which I have had great results in gaining muscle before whey became popular. It has a higher glutamine content than whey which can help spare muscle during intense training. It's also slower to digest since it curdles or forms a gel in the gut. This slows transit time prolonging the exposure of protein to the intestinal tract that can help increase protein absorption.
Milk isolates are a combination of whey and casein, concentrated to 90% protein with all of the lactose removed. They have the functional properties of both whey and casein.
Egg protein is used in some formulas in the form of egg albumin (egg white). Egg was the gold standard in protein for many years but its dominance has been knocked off by other proteins that contain additional functional benefits.
Soy protein is not generally used for building muscle since it has low levels of the essential amino acid methionine. Vegetable proteins in general are incomplete proteins and are not as good for building muscle as animal proteins. However, I think you should still consume soy for its other functional benefits for your heart and overall long term health. Most people are now adding in a scoop of pure soy into their protein shakes.Answer: Lindberg Store Manager
The bottom line is one protein is not a clear cut winner. A combination is what I recommend. Mixing a whey protein powder in milk gives you a good combination. I lean toward meal replacement powders for gaining muscle since they provide carbs in addition to protein and most have a combination of the milk and whey proteins.Most meal replacement manufacturers use a proprietary blend of proteins since they're afraid of people copying their formula. But that means you never know exactly how much of each protein is in the formula. However, Fitness Labs has set a new standard in the industry by actually printing the amounts of each protein source on the label of their NutraFit meal replacement to help you make more educated purchasing decisions. It's the one I take now and it tastes really good. Each serving has 40 grams of protein (40% is from whey, 40% is from casein, and 20% is from milk isolates which is a combination of whey and casein). This is roughly the 50:50 ratio mentioned above.
If you use a whey protein for gaining muscle, mix it in lowfat or nonfat milk, add carbs like a banana or eat other foods with carbs at the same time so that you never go into calorie deficit. Burn the carbs in your diet for energy, not valuable protein which can hamper your muscle growth.