The human body requires, as its main source of fuel or energy, a special sugar called glucose. The body produces glucose from food containing carbohydrates, such as bread, cereals, rice, pasta, potatoes, milk, yoghurt, and fruits. Glucose is carried to the entire body through blood – its level should not be either too high or too low. When glucose exceeds a certain level, part of it must exit the blood and enter the tissues of the body, in order to provide the energy required by cells and ensure the proper function of the body. Part of glucose is stored also in the liver, in order to be used later if needed. When the glucose level falls too much, part of the glucose stored in the liver is released in the blood stream in order to restore it. Insulin is a hormone produced by the pancreas, a gland located exactly beneath the stomach. Insulin is like a key opening the “gates” of the cells in the body, allowing glucose to pass through the blood to the cells, where it can be used as energy. This procedure is called glucose metabolism. In diabetes, the pancreas either cannot produce insulin, or the insulin produced cannot operate properly. Without the assistance of insulin, the passages of glucose are closed. Glucose is accumulated in the body, leading to high glucose levels in the blood, which in turn cause health problems related to diabetes.