A debate in defining fiber

Prepared Foods, Jan, 2002

"Dietary fiber, by definition, are compounds that are found naturally in plants or plant cell walls that are not digested by the body. It's a very broad topic... The newest fibers, such as inulin, resistant maltodextrins and oligosaccharides are easily incorporated fiber sources, but are too soluble to be picked up 100% by FDA-approved labeling methods," opines Bryan Tungland, vice president, scientific and regulatory affairs, Imperial Sensus LLC, an inulin manufacturer based in Sugar Land, Texas.

Currently, FDA defines "fiber" for nutritional labeling purposes based on approved AOAC Official Methods of Analysis (or other analyses that are accurate and precise).

Presently, the food industry is utilizing two proposed definitions. The first one, put forth by the American Association of Cereal Chemists (AACC) in September 2000, is relatively simple. It says dietary fiber is composed of products that are not digested in the small intestine and which are partially fermented in the large intestine; it includes analogous substances such as polydextrose, methylcellulose, resistant starches and resistant dextrins. A second definition, drafted in September 2001 by the National Academy of Sciences (Institute of Medicine), offers a more detailed description of fiber, but is still consistent with the first definition. While the two proposals are consistent with their overall message, the latter has elements that make it more difficult to write policy and regulate using existing analytical methods, Tungland suggests.

In particular, the two definitions disagree as to how to classify these "fibers".

This non-agreement about what constitutes dietary fiber is at the center of a heated debate whose outcome will affect government and regulatory entities, food industry representatives, food and beverage manufacturers, academia, research and methods development personnel. The FDA has yet to respond to these proposed definitions. It is not known how the FDA will respond.

Adding fiber to the diet has been proven to promote good intestinal health by maintaining healthy serum cholesterol and blood glucose levels, maintaining healthy serum triglycerides and promoting healthy laxation. Yet, "Americans only consume 50% of their daily value (25g based on a 2,000 calorie diet) of dietary fiber," states Steve Young, Ph.D, Houston, TX, and technical adviser to Matsutani America Inc., manufacturer of a digestion resistant maltodextrin. Recently, fiber has been tied to successful weight management programs, he adds.

Fiber ingredients are not meant to replace fruits and vegetables but can help bridge the gap between what consumers need and what they are eating, says Donna Brooks, product manager at Danisco Sweeteners, a polydextrose manufacturer, Ardsley NY. "Sometimes, people still think of fiber and constipation and old people. But, fiber is not just for a select group-everyone needs additional fiber in their foods."