Vitamins, minerals, fiber, and other protective substances in whole grain foods contribute to the health benefits of whole grains. Refined grains are low in fiber and in the protective substances that accompany fiber.
Eating plenty of fiber-containing foods, such as whole grains (and also many fruits and vegetables) promotes proper bowel function. The high fiber content of many whole grains may also help you to feel full with fewer calories. Fiber is best obtained from foods like whole grains, fruits, and vegetables rather than from fiber supplements for several reasons: there are many types of fiber, the composition of fiber is poorly understood, and other protective substances accompany fiber in foods. Use the Nutrition Facts Label to help choose grains that are rich in fiber and low in saturated fat and sodium.