Except for fiber, which cannot be digested, both simple and complex carbohydrates are converted into glucose. The glucose is then either used directly to provide energy for the body, or stored in the liver for future use. When a person consumes more calories than the body is using, a portion of the carbohydrates consumed may also be stored in the body as fat. Refined foods offer few, if any, of the vitamins and minerals that are important to your health. Yet another problem is that foods high in refined simple sugars often are also high in fats, which should be limited in a healthy diet.
Dietary fiber is the part of a plant that is resistant to the body's digestive enzymes.
Only a relatively small amount of fiber is digested or metabolized in the stomach or intestines. Most of it moves through the gastrointestinal tract and ends up in the stool. Although most fiber is not digested, it delivers several important health benefits. First, fiber retains water, resulting in softer and bulkier stools that prevent constipation and hemorrhoids. A high-fiber diet also reduces the risk of colon cancer, perhaps by speeding the rate at which stool passes through the intestine and by keeping the digestive tract clean.