ST. PAUL, MINN. — While the Food and Drug Administration plans to define fiber, an article published April 12 in Nutrition Journal makes the case a definition should include fiber found intrinsically in food and also added to food.

Julie Miller Jones, Ph.D., professor emeritus, foods and nutrition, at St. Catherine University in St. Paul, Minn., wrote the paper. The Calorie Control Council, an international association representing the low- and reduced-calorie food and beverage industry, gave funds to help prepare the manuscript.

“Since the intake of dietary fiber is significantly below recommended levels throughout the world, the recognition that ‘all fibers fit’ is an important strategy in bridging the fiber gap by enfranchising and encouraging greater intake of foods with inherent and added dietary fiber,” Dr. Jones said. “Fortifying foods with added dietary fiber makes it easier to increase intakes while maintaining calories at recommended levels.”

She pointed to NHANES data from 2001-04 showing under 5% of consumers in most age and gender categories fail to meet adequate intake levels for fiber

The F.D.A., while proposing changes to the Nutrition Facts Panel found on food packages, also pointed out the need for a fiber definition.

“Currently, there are no analytical methods that can distinguish between dietary fiber (soluble and insoluble fiber) and non-digestible carbohydrates that do not meet the definition of dietary fiber, the F.D.A. said in the March 3 Federal Register.

The F.D.A. pointed to an Institute of Medicine definition in which “total fiber” is the sum of “dietary fiber” and “added fiber.” According to the Institute of Medicine, dietary fiber consists of non-digestible carbohydrates and lignin that are intrinsic and intact in plants, and added fiber consists of isolated, non-digestible carbohydrates that have beneficial physiological effects in humans.

Dr. Jones in her article said a varied diet that uses fiber-fortified foods together with fiber-rich foods has multiple benefits.

“Statements by some health professionals and in corporate advertising campaigns suggest that added fibers are ‘fake’ and that only foods with natural fiber can fulfill DF (dietary fiber) requirements,” she said. “While it is true that added fibers may not carry all the ‘co-passengers’ found in the food fiber matrix, isolated fibers do show documented health benefits. In fact, these benefits are so well-documented that many countries allow health claims for isolated fibers such as wheat bran and B-glucan and its derivatives.”

Fibers are analogous to vitamins in that they vary in structure, function and amount needed, she said.

“Constructing a diet with a balance of DF types is analogous to constructing a diet with the correct amount and balance of the vitamins needed for optimal health,” Dr. Jones said. “The similarities are outlined as follows. First, vitamin requirements are fulfilled only when all vitamins are present in both quantity and type. In like manner for DF, the optimal diet would have both right quantity of total DF and balance of fiber types.

“Second, vitamins inherently in food and those added through fortification and enrichment can work together to fulfill the requirements. The same can apply to DF in that added fibers can interact with intrinsic fibers to meet the requirement act synergistically actually to reap health benefits.”

She referred to the CODEX Alimentarius Commission (CAC) adopting a comprehensive dietary fiber definition that was published in 2009.

The Codex Alimentarius Commission, part of the World Health Organization Food and Agriculture Organization, defined dietary fiber as carbohydrate polymers with 10 or more monomeric units, which are not hydrolyzed by the endogenous enzymes in the small intestine of humans and belong to the following categories:

• edible carbohydrate polymers naturally occurring in the food as consumed,

• carbohydrate polymers, obtained from food raw material by physical, enzymatic or chemical means,

• synthetic carbohydrate polymers.

The CAC noted isolated or synthetic fibers must show a proven physiological benefit to health as demonstrated by generally accepted scientific evidence to competent authorities.