How Fake is Your Fiber?: Intact vs. Isolated Fibers

21 Nov

How Fake is Your Fiber?: Intact vs. Isolated Fibers

Food manufacturers are wising up to the public’s interest in increasing dietary fiber. You can find fiber in foods where it never existed: Fiber One’s High Fiber Yogurt, Skinny Cow Ice Cream Sandwiches and now even Splenda has fiber. But are all fibers created equal? Not if you look closely…

The Nutrition Facts Panel tells you the total grams of Dietary Fiber in a packaged food’s serving. What it doesn’t tell you is whether that fiber is from intact fiber (found in foods naturally high in fiber like whole grains, fruits and vegetables) or isolated fiber (fibers derived from other starchy foods and added to non-fiber containing foods to make them higher in fiber). To find out if your fiber is from intact or isolated sources (also called functional, nondigestible fibers), you have to look at the Ingredients List – located right below the Nutrition Facts Panel on food packaging.

The most common isolated fibers manufacturers use to bulk up not-so-fibrous foods include:

  • Maltodextrin
  • Inulin (chicory root)
  • Polydextrose
  • Oat fiber
  • Resistant starch
  • Pectin
  • Gum

Foods with functional fibers highlighted in this blog include Mission Carb Control Tortillas (modified food starch) and Oroweat Sandwich Thins

(polydextrose).

Do the health benefits of dietary fiber include those of isolated fiber? Not exactly. The American Dietetic Association Position Paper on Dietary Fiber (J Am Diet Assoc. 2008;108:1716-1731) says, “Whether isolated, functional fibers provide protection against cardiovascular disease remains controversial.” The position paper goes on to say, “longer-term studies of fiber intake which examine the effects of both intrinsic [intact] and functional [isolated] fibers…are required.”

While we don’t know exactly whether the health benefits of dietary fiber are attributable to intact fiber, the additional nutrients in those high fiber foods or even the healthier habits of high-fiber-diet-eating people, most dietitians and nutrition professionals recommend sticking to foods that are naturally high in fiber: fruits, vegetables, whole grains and legumes like lentils and dried peas and beans and taking it easy on the faker fiber foods.

You may be better served to go middle of the road on your fiber-containing foods:

  • Instead of a hot cereal with added isolated fiber such as Kashi GoLean (chicory root) fiber and 5 grams of fiber per serving, try Quaker Quick Oatswith a naturally occurring 4 grams of fiber per serving – all from good old fashioned 100% rolled oats
  • Instead of Oroweat Double Fiber Bread (modified tapioca starch) and 6 grams of fiber per serving, try their regular 100% whole wheat bread with 3 grams of fiber from whole wheat flour
  • …and if you’re looking for a naturally occurring high fiber yogurt…well…some things just weren’t meant to be!

Trackbacks and Pingbacks

  1. Fiber: Your Gut’s BFF « Fabulously Domestic - August 15, 2011

    [...] as traditional intact fiber.  For more on these “fake fibers”, I recommend you read this brief article over at Fiber is the Future, authored by Registered Dietitian Katie Clark, MPH, RD, [...]

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