According to Mayo Clinic, fiber helps to normalize bowel movements by softening stool while increasing its weight and size, making it easier to pass and reducing the risk of constipation. Fiber also helps to maintain bowel and colon health, lower cholesterol, control blood sugar levels and manage weight. It can lower the risk of diabetes and heart disease as well.
According to MedlinePlus, there are two types of fiber: soluble and insoluble. Soluble fiber absorbs water and turns into a gel-like substance during digestion, which slows down the digestive process. Soluble fiber is found in some fruits and vegetables, barley, bran, nuts, seeds, beans and peas. This slow-moving fiber has been proven to help lower cholesterol and help prevent heart disease. Unlike soluble fiber, insoluble fiber speeds up the digestive process by adding bulk to the stool and causing food to pass through the stomach and intestines more quickly. Whole grains and vegetables contain insoluble fiber.
Mayo Clinic explains that fiber, namely soluble fiber, also helps to reduce blood sugar levels by slowing the absorption of sugar in the blood, thus reducing the risk of diabetes. Fiber can also help individuals feel fuller during mealtimes, which may reduce a person's desire to overeat.