Fiber is found naturally in many of the foods we eat, like fruits and vegetables, whole grains and legumes. Naturally occurring fiber prevents constipation, lowers the risk of diabetes and heart disease, and even helps maintain our weight [source: Mayo Clinic].
Grocery store shelves are filled with foods that have unexpected additions of fiber, like yogurt, ice cream, sugary cereals and even water. Unfortunately, these fiber-added foods don't offer the same benefits as foods that are naturally high in fiber.
That's because whole foods like oatmeal contain complex fiber, but fiber-enriched foods like white bread rely on a single type of fiber. These isolated fibers are either chemically synthesized or extracted from fiber-rich plants. While isolated fibers do have some benefits, like helping you feel full, there are often too few in a single serving to make much of a difference to your health. In addition, isolated fibers aren't efficient at encouraging bowel movements, and have little impact on blood sugar or cholesterol. Consumed in large amounts, they can cause gas and bloating [source: Berkeley Wellness].
In the end, we're better off eating foods that are naturally fiber-rich because they contain a variety of fibers with clear health benefits. A bagel made with refined flour, that has been fortified with the chemically synthesized fiber, just isn't as good for the body as the whole grain version [source: Berkeley Wellness, Cooking Light].