Protein is a part of every cell in your body, and no other nutrient plays as many different roles in keeping you alive and healthy. The importance of protein for the growth and repair of your muscles, bones, skin, tendons, ligaments, hair, eyes and other tissues is proven since a very long time. Without it, you would lack the enzymes and hormones you need for metabolism, digestion and other important processes.

When you have an infection, you should eat more protein because it helps create the antibodies your immune system needs to fight disease. If you are injured, you may need more, as well, to help your blood clot and make repairs. Your body can use protein for energy, if necessary, but it’s best to eat plenty of carbohydrates for that purpose and save your protein for the important jobs other nutrients cannot do.

Pick Your Protein Carefully
Your body needs many different proteins for various purposes. It makes them from about 20 'building blocks' called amino acids. Nine of these are essential amino acid, which means you must get them from food. The others are nonessential. This does not mean you do not need them. You just do not have to eat them because your body can produce them.