Starch is a carbohydrate, and the main purpose of carbohydrates is to provide energy for the body, according to The New York Times. The enzyme amylase is responsible for the conversion of starches into glucose, or blood sugar, which is used as energy for the body, particularly in the brain and nervous system. Starchy foods include legumes, whole grain breads and cereals, and starchy vegetables, such as potatoes.
Not eating enough starch and carbohydrates can result in malnutrition or the intake of too much fat in the diet to overcompensate for the lack of calories, according to The New York Times. Too many starches in the diet leads to obesity. Ideally, between 40 and 60 percent of all daily calories come from starches and natural sugars. These provide necessary calories, vitamins, minerals and fiber in the diet.
To increase starch intake, a diet high in whole grain bread, rice and cereal, and legumes, such as beans, lentils and dried peas, is recommended, according to The New York Times. Typical serving sizes for starches vary based on the item. One piece of bread, 1/2 cup of cooked rice, pasta, cereal, beans, lentils or peas, and 2/3 cup of ready-to-eat cereals are considered general serving sizes for starchy items.