A. “Fiber enhances intestinal activity and improves regularity,” says Amy Foxx-Orenstein, D.O., a gastroenterologist at the Mayo Clinic in Rochester, Minnesota. “In general, a poor diet that is low in fiber and high in fat can lead to intestinal irregularity, symptoms of gas and bloating and disordered stool patterns.” Fiber absorbs fluid in the intestine, making stool softer and easier to pass. It improves the body’s elimination of natural waste (including toxins). There’s some evidence to suggest that fiber may improve our ability to metabolize fat and can help curb appetite. Aim to get 25 to 30 grams of fiber each day, from natural sources like vegetables, fruits, whole grains and beans.