Top high protein foods. Protein is a macronutrient required for building muscle. It is commonly found in animal products, although it is also present in other sources such as nuts and legumes. 1.whey protein Whey is a liquid that is obtained by solidifying and filtering milk. It is a by-product of cheese or casein manufacturing and has several commercial uses. Sweet whey is a by-product of the production of rennet-type hard cheeses such as cheddar and Swiss cheese. Acid serum (also called sour whey) The fallopian tubes appeared during the production of acid-type dairy products, such as cottage cheese and strain yogurt. 2.egg Egg white is a clear liquid (aka albumin or glare/glare) contained in eggs. In the chicken, during the passage of the egg it is formed from a layer of secretions from the anterior part of the chicken oviduct. Formed around fertilized or unfertilized yolk. Egg white's main natural purpose is to protect the yolk a...