Any bodybuilder with a rudimentary understanding of the sport would know the key to gaining muscle is protein consumption. Granted, training, rest and other nutrients all enhance anabolism, and growth, but protein (being the key size-building nutrient) is absolutely essential when it comes to packing it on - 60-70% of bodily protein is found in muscle.
In fact, protein is the key "building" nutrient for a variety of bodily tissues, many of which support muscle growth (enzymes, skin, hair, nails, bones, and connective tissue are all constructed from protein). Protein makes up 15-20% of ones bodyweight and is thus, next to water, the body's second most abundant substance.
The inescapable fact remains: protein, and only protein, is the raw material from which muscle and many other bodily tissues are built. Proteins themselves are formed from amino-acids, of which there are 20, comprised of both essential and non-essential.
Non-essential aminos can be produced by the liver. However, essential aminos must be made available through the diet before any muscle can be synthesized. Therefore, the correct ratios of essential and non-essential amino acids should be made available in sufficient quantities before any muscle can be produced.
Essential Amino Acids http://www.bodybuilding.com/fun/drobson75.htm
Non Essential Amino Acids
- Aspartic Acid
- Glutamic acid
Obtaining the correct ratio of essential and non-essential amino acids involves eating complete protein sources such as eggs, meat and milk. As stated, protein is crucially important for muscle growth, it is however (at a more basic level), the building-block amino-acids that need to be in place, in the correct proportions, to ensure an optimal anabolic environment.