What is protein and why do we need it?
A protein is a molecule made from chemicals called amino acids that our bodies need to function properly. They are essential to repair the body’s daily wear and tear.
Protein helps in the following ways:
It is required to build lean body mass. For example, actin and myosin are the proteins present in our skeletal muscles, our hair structure is designed by a protein called keratin, and collagen is a protein that provides the soft framework for our bones.
Our immune system also requires protein to fight infection. As well, our hormones like insulin, the human growth hormones (except for sex hormones), and enzymes like digestive enzymes, which act as catalyst in biochemical reactions, are all made up of protein.
Proteins also carry oxygen through our blood. For instance, hemoglobin - globin is a protein molecule - carries oxygen through our body.
How much protein do I need a day?
Protein requirement varies by individual (and lifestyle), but is generally between 0.8 gm and 2 gm per kilogram of body weight. The higher range is for active people eating a diet that contains a calculated amount of calories for optimal performance and daily energy needs.
If you don’t exercise, you won’t get any additional benefit from eating high amounts of protein as your body simply does not experience the level of breakdown and rebuilding that comes with intense exercise. Research has shown that consuming more than 2 grams of protein per day gives no added benefit, in fact it can stress the liver and the kidneys.
In what food can I find protein?
What is protein quality dependent on?
As protein is made from amino acids, the presence of all amino acids in optimum quantities decides the quality of protein. There are 20 different amino acids in all, nine of which can’t be produced by the human body. These are known as ‘essential’ amino acids and we need to get them from the food we eat.