PROTEIN A combination of amino acids, some of which are called essential because the human body needs them but can't synthesize them. The human diet must regulary supply protein which contains all of the essential amino acids. The egg boasts them all: histidine, isoleucine, leucine, lysine, methionine, Phenylalanine, threonine, tryptophan and valine. They are present in a pattern that matches very closely the pattern the body needs, so the egg is often the measuring stick by which other protein foods are measured.
In addition to the 9 essential amino acids, there are 9 other amino acids in an egg. Altogether, each Large egg provides it total of 6.25 grams of high-quality, complete protein. For this reason, the egg is classified with meat in the food categories. One egg = I ounce of lean meat, fish or poultry. A Large egg provides 10 to 13% of the Daily Reference Value for protein and varying amounts of many other nutrients, too. -see Biological Value, Buying, Nutrient, Nutrient Density