Protein provides four calories per gram. The human body can do three things with protein calories; put protein in fat stores, use it as an energy source or use it to carry out functions vital to life. Protein calories will be used as an energy source when the body is lacking fat or carbohydrate calories for fuel. When the body receives sufficient quantities of proteins, fats and carbohydrates, protein will carry out its specific functions. These proteins functions include: replacement of old cells, building muscles, organs, blood, nails, hair, skin, and tissues. Protein also takes part in hormone, antibodies, and enzyme formation.
Fasting your body without proper protein intake will cause your body to slowly start shutting down. You must not only eat enough protein, but you must eat the right types. Without the right amount of essential proteins, no matter how much you eat, your body will waste the protein and not run properly.
A diet that is low in essential amino acids does not carry out all of its protein functions. Protein follows the all-or-none law: inadequate amounts of essential amino acids cause the body to excrete proteins in urine as urea. The remainder of the protein is converted to glucose, fat, or metabolized for energy. This lack of essential amino acids prevents proteins from performing their normal functions. Foods that have all nine of the essential amino acids are called complete proteins. Complete proteins include all food from animal products, milk, cheese, chicken, beef, and ext. Don't worry folks! Proteins that are incomplete (plant products) can be combined with complementary proteins that carry the missing amino acids to form a complete protein. Examples of incomplete protein are grains, cereals, and vegetables. To complement these proteins you would combine beans with grains, or nuts with cereal.