Table of Contents
What Is Protein?
The word protein is derived from Greek and means "prime importance". This is because they are the building blocks that make up a variety of structures in the human body including hair, muscle, cartilage and ligaments. We generally gain protein from eating meat and dairy products and the diet should consist of between 10 and 20 percent protein depending on your specific needs. A person who is training heavily will need a higher percentage of protein to help the muscles recover quickly and allow a higher level of training. Even an average person who does little exercise still needs a good amount of protein to keep the body functioning effectively. It is important to note that 1g of protein has 4 calories.
Why Do We Need Protein?
When we eat protein it is digested in the digestive system and delivered to the liver as individual amino acids. The liver then rebuilds those amino acids into long chains to make protein again which can be used by the body. Depending on the needs of the body at that time the protein is redistributed for example if the muscles are repairing the proteins are used to repair the muscle tissue.
- to build structures
- to perform functions
- to provide fuel (only a small amount)
Proteins make up the structures such as muscle, bone, organs, connective tissue, hair and nails so it is an extremely important part of our diet. In terms of its functions, protein helps to allow hormones to work effectively sending messages (insulin and adrenaline), helps the effectiveness of enzymes in chemical reactions, they make up parts of the immune system (white blood cells are partly protein) and they help to form lipoproteins which help the body transport fat.
The smallest unit of a protein is an amino acid and all proteins are made up of chains of these amino acids which are formed into structures. In total there are 20 amino acids and they can be seen like the alphabet, which has 26 letters which make up millions of words. The 20 amino acids combine into approximately 50,000 different combinations to form different protein structures in the body. Just as different words have different meanings, different structures of amino acids produce different parts such as muscle and cartilage.
The higher the amount of amino acids found in a source of protein the better quality it is. Foods can be given a protein rating based on this information and the highest rating is 100 which is given to eggs as this contains the highest amount of amino acids. All other foods are then compared to eggs to get a rating of the quality and quantity of amino acids. Other foods which have a high protein rating are fish (70), beef (69), cows milk (60). Some of the lower quality proteins are things like beans and peanuts which are between 30-45 but they are still considered foods high in protein and essential in our diet.