Since protein is one of the fundamental building blocks for the body, you need to ensure that you get enough of it. Every protein molecule is composed of amino acids. Twenty amino acids are used in different combinations to build the protein molecules found in food and in the body's structures. Nine of these amino acids are considered essential. Instead, it means that these nine amino acids are available to humans only through the diet.
Dietary protein is found in most foods and is the primary source of amino acids for the body.
Foods containing protein include but are not limited to beef, chicken, fish, pork, dairy, eggs, nuts, grains, beans. Protein can also be found in vegetables and fruit. Not all protein-containing foods are alike. Each protein source has a different combination of amino acids. Some foods may contain high amounts of essential amino acids while other foods may be low.