Fiber versus Fiber – What’s the Difference?

How’s your fiber intake? If you’re like most people, you probably fall short. While dietitians recommend adults consume between 25 and 35 grams of fiber a day, most Americans get less than half that amount— more like 15 grams a day. Fiber is not only critical for good health and proper nutrition, it can play an important role in your weight loss arsenal as well.

What is fiber, anyway? It’s the part of plant foods that cannot be digested, and falls into two categories—soluble and insoluble. The two types react differently in water. Soluble fiber dissolves in water and becomes gummy, acting like a sponge to soak up “bad” cholesterol. Insoluble fiber doesn’t dissolve in water and acts more like a broom, essentially “sweeping” out your intestines and helping keep you regular.

A diet high in fiber may help reduce your risk of certain conditions like heart disease, high blood pressure, diverticulosis, and some forms of cancer. Fiber also helps with weight loss, because high-fiber foods make you feel full longer and take longer to digest.

Food manufacturers are responding to the growing desire for fiber by putting it in places you’d never think of—yogurt, juice, artificial sweeteners, and even water. How is this possible? Because this new fiber is an “isolated fiber” like inulin or polydextrose. These purified fibers aren’t the same as intact fiber found naturally in foods like fruits, vegetables, beans, and legumes. And while it may count toward the fiber content on the label, the jury’s still out on the potential health benefits of isolated fiber. (Some studies suggest inulin may help boost the beneficial bacteria found in the digestive tract, but there’s no evidence it promotes regularity or lowers cholesterol the way regular fiber does.)

The bottom line with fiber is that you’re better off getting intact fiber from whole foods that naturally contain it, rather than from foods with fiber added as a marketing ploy. That means including fruits and vegetables, beans, legumes, whole grains, and nuts in your regular diet.

For more information, check out my tips on “5 Signs You’re Not Getting Enough Fiber” in SELF magazine.