Women under age 50 need 25 grams of fiber daily, and men under age 50 need 38 grams of fiber each day; however, most Americans eat about 15 grams of fiber each day. Fiber can't be digested, so it adds bulk to the stool and slows down gastric emptying.
The two types of fiber are soluble fiber and insoluble fiber. Soluble fiber helps lower cholesterol and control blood glucose levels. It is found in foods such as beans, oats, nuts and apples. Insoluble fiber assists with regular bowel movements and is found in foods such as whole grains, carrots and raisins.