Deficit of insulin or lack of senses from receptors of insulin is the main reason of diabetes mellitus. Insulin is the main Hormone which controls intake of glucose in most of the cells of the body which includes cells of the muscles.

Within a short span of a couple of hours most of the carbohydrates are converted into monosaccharide glucose which is the main carbohydrate in blood. There are carbohydrates in the food which are not convertible like fruit sugar also called Fructose which are used as fuel for cells. These carbohydrates do not take part in the metabolic mechanism of glucose. Moreover cellulose which is a carbohydrate is not converted to glucose as the digestive system of humans does not have mechanism of digesting cellulose. Beta cells in the pancreas releases insulin into the body which is a response to the rise in level of glucose in the blood. Glucose is absorbed from the blood, used as fuel for the body, converted to other molecules required and stored, which is due to insulin in the body. Insulin also acts as a catalyst when glucose is converted to glycogen which is stored in the liver cells. When the glucose level reduces, the insulin level released by the beta cells in the blood also reduces and a reverse reaction takes place when glycogen is converted into glucose.

Due to the higher levels of insulin in the blood there are many anabolic processes which are increased like growth, duplication in cells and storage of fat. Insulin is the main component in the body which converts many bi directional process of metabolism which includes conversion from catabolic to anabolic mechanism. Insulin is the main component which burns fat in the body.

The amount of insulin available in the body should be sufficient so that glucose is used properly by the body and stored. If the amount of insulin is not sufficient then cells will not respond well to the effects of insulin. This results in high levels of glucose in the blood, synthesis of proteins will be poor and other metabolic disorders like acidosis.