PROTEINS.
These are sometimes called albumen, and they supply the body with nitrogen, sulphur and phosphorus. They are great tissue builders; they also furnish energy and heat, in combination with fats and carbohydrates.
Sources of Proteins:
Legumes, lean meats, nuts, cheese, whites of eggs, fish, and the glutens of the grains. Milk contains proteins in the right proportion with fats and sugars to make it suitable as a food for infants. Oats, wheat, and rye contain more protein than other grains, and if no other protein foods are on hand, these can maintain health for a long time without harm.