Protein, called protein include, in addition to carbohydrates and fats to the main nutrients in our diet. They are composed of chains of amino acids and perform many functions in our body. Proteins, for example, help build new cells, in strengthening the immune system, in muscle contraction, build and maintain muscle mass, in storing iron, the transport of oxygen or fat and they enable and accelerate chemical reactions in the body.

Proteins are classified into different groups based on their quality and digestibility as well as their source, e.g. whey protein, casein, milk protein isolate, egg protein and soy protein.