The foods we eat contain nutrients that provide energy and other things the body
needs. Most of the nutrients in food fall into three major groups: proteins, fats,
and carbohydrates. The two main forms of carbohydrates are sugars (such as fructose,
glucose, and lactose) and starches, which are found in foods such as starchy vegetables,
grains, rice, breads, and cereals. The body breaks down (or converts) most carbohydrates
into the sugar glucose, which is absorbed into the bloodstream. As the glucose level
rises in the body, the pancreas releases a hormone called insulin. Insulin is needed
to move sugar from the blood into the cells, where it can be used as a source of energy.