As if body building were that easy! The one absolute sure way to slow down muscle loss with aging or to build muscle is with strength training. How much and which kind of protein we eat, and how it is distributed throughout the day also matters. What science knows and what people are doing are at opposite ends of the spectrum.
On average, 30 grams of protein per meal is the maximum amount the body can synthesize at a time; the excess will be converted to fat. High quality protien comes from animal sources, i.e. fish, dairy, eggs, meats. Leucine seems to be the most important of the amino acids that make up animal proteins. In fact, researchers believe it is the key ingredient which provides the driving force of protein synthesis (muscle building). Milk contains whey protein, which has the highest concentration of leucine, making it a popular ingredient in bodybuilding powders. Vegetables contain some leucine, soy ranking the highest, though not as efficient for synthesis.
The largest anabolic (tissue-building) response to protein consumption is after exercise. During exercise, the signaling proteins that regulate synthesis shut down.
And what about those popular liquid supplements? Made up of mostly water, sugar, vegetable oil and a vitamin supplement, they contain the same amount of protien as 2 cups of skim milk, for about 3 times the cost. The metabolite HMB, a.k.a. "Revigor" mentioned on one of the bottled types does not contain enough of the ingredient to be effective. Even in studies where participants took 5 times the amount of HMB found in the supplement, along with arginine and lysine, and regular strength training, showed no more increase in muscle tissue after one year than those taking a placebo.
Creatine, however, has shown evidence as being the most effective and safest supplement for improving muscle size, when used properly and accompanied with resistance training. Creatine is a natural compound found in the body and in foods such as meat, fish, and poultry. Creatine makes energy available to muscles during exercise, and "plumps" muscles with added fluids. Older adults tend to benefit the most from creatine supplements, since the body slows down the natural production with the aging process. Vegans benefit also, since they don't get so much from their diet.
~ Journal of Parenteral and Enteral Nutrition, 2009