Starch is a nutrient of the type called carbohydrates. Starches are also called complex carbohydrates because they are made up of chains of simple carbohydrates or sugars. When starches are metabolized, they are first broken up into fast-acting sugars.
Carbohydrates provide the body with the energy it needs for physical activity. Starches are just one of the three types of carbohydrates, the others being simple carbohydrates and fiber. Foods that are rich in starch include peas, corn, beans, potatoes, lentils and grains, such as wheat, barley and oats. In grains, starch is found mostly in the soft part in the center of the grain called the endosperm.