It is really hard to gain a large amount of muscle, to the point where you are a freak. Understand that eating excess protein doesn't cause muscle growth and that there are 10 essential amino acids that can not be made by your body and are required in your diet. So what is protein? Proteins are molecules built up of long chains of amino acids and the type of protein is dictated by the different combinations and sequences of amino acids. To build a protein, amino acids are connected into a long chain, this is known as the primary structure. The chain is then folded into a secondary, tertiary and quaternary structure forming a protein. The human body utilises 21 amino acids to make all the proteins it needs to function and grow. There are certain amino acids known as essential amino acids, EAAs, which are essential because they cannot synthesised by the human body. Therefore it is essential that we get these in our diet. Protein is not just need to build and repair muscles, but also needed to build and repair all cells within the body. They are also needed for the production of hormones which are chemicals produced by glands. Protein hormones bind to receptors on the cell membrane and cause a range of downstream effects on the body and coordinate activities. For example hormones control blood sugar levels, the control of puberty, egg and sperm production, pregnancy, birth. Control our fight or flight responses, control the feeling of hunger and even control our metabolism. Proteins are also used for the production of enzymes. Molecules that bind to molecules to speed up chemical reactions. They are responsible for constructing, synthesising, carrying, dispensing, delivering, and eliminating the many ingredients and chemicals our body uses everyday. For example amylase and lipase are enzymes that help you to digest carbohydrates and fat respectively. Antibodies of the immune system are also constructed of proteins. They are produced by the body to fight infection against bacteria and viruses. Protein can also be broken down into amino acids during digestion and provide a source of energy. Although protein can be used as an energy source, the body's main energy source is carbohydrates. Eating a diet with lean proteins has a powerful satiating effect, along with a high thermic effect, the amount of calories required by the body to break down a given a food. So eating more protein can help you control your calories, as this has been shown to lead to restricting calories due to the satiety it causes. (1) So do not fear protein. Follow my Blog, my Twitter and Facebook for more fitness and nutrition tips and information.