Like proteins and fats, carbohydrates are one of the three main nutrients in food. Carbohydrates (carbs) are the body's major source of energy. There are two main types of carbohydrates – sugars (like the kinds in milk, fruit, table sugar, and candy) and starches, which are found in grains, breads, crackers, and pasta.
The body breaks down carbs into the sugar glucose (say: gloo-kose), which the body's cells need. Glucose is absorbed into the bloodstream, which makes the sugar level in the blood go up. As the sugar level rises in the body, the pancreas releases a hormone called insulin (say: in-suh-lin). Insulin is needed to move glucose from the blood into the cells, where it can be used as a source of energy.