Proteins are essential nutrients for the human body, because there are no protein stores in the body. New proteins are provided only through food. Their functions are numerous, they serve as enzymes, they transport materials throughout the body (hemoglobin), molecules for storing certain elements, hormone, muscle building, antibodies, etc. The most valuable source of proteins (containing all necessary amino acids) are meat, milk and eggs. Vegetables, cereals, beans, peas, nuts, almonds and hazelnuts are the source of incomplete proteins, although by proper combining of these foods, satisfactory amino acid composition can be obtained.