Fibers, Flours, Grains / Dietary Guidelines

The New Definition of Fiber

The FDA has adopted an official definition of dietary fiber. Under the new definition, how will ingredient suppliers and food companies get their fibers approved?

By Lauren R. Hartman, Product Development Editor

Fiber ingredient suppliers and food companies have been waiting with interest for a few years, but finally, here come the "fiberworks." The FDA defined the term dietary fiber in May as part of its efforts to update the Nutritional Facts panel of food products since its debut more than 20 years ago. The agency now restricts fiber to naturally occurring fibers and those with a physiological benefit. It also increased the Dietary Reference Values (DRV) of dietary fiber, which includes both soluble and insoluble fiber, from 25 to 28g.

For ingredient suppliers and food companies, the definition could add the challenges of having to identify their food ingredients as starch, oats and fiber on a package label. Manufacturers concerned about how the changes will affect the updated Nutrition Facts panel have additional issues. With the changing definition, certain fiber claims on products are at risk, as are some products themselves. Any "newly isolated or manufactured dietary fiber" would need to deal with additional evaluations before being allowed to be listed as dietary fiber on food packaging.

Fiber WheatUntil this year, FDA regulations didn't define dietary fiber, and instead relied on analytical methods for measuring levels of dietary fiber present in food. This meant an isolated or synthetic, non-digestible carbohydrate could be added to foods and quantified as a dietary fiber, even if it didn't necessarily provide a beneficial physiological effect to human health.

The FDA-approved health claims recognize that soluble fiber as part of a diet low in saturated fat and cholesterol plays a major role in reducing heart disease risks. A fiber-rich diet has been well documented to have numerous benefits supported by substantial scientific research.

According to the new FDA plan, manufacturers adding fiber to foods—either by isolating it from other foods or synthesizing it—will need to demonstrate one beneficial physiological effect to human health to meet the definition's requirements.

So what existing carbohydrates can be considered dietary fiber content? And for those not yet recognized as dietary fiber, what physiological benefits have to be demonstrated?

First, to be considered a dietary fiber that may be declared on a food package label, a carbohydrate must exhibit certain physiological effects to be eligible: Lowering blood glucose and cholesterol levels; lowering blood pressure; improving laxation and bowel function; increasing mineral absorption in the intestinal tract; reducing energy intake (for example, from the fiber promoting a feeling of fullness). Other physiological values can be added to the list if scientific evidence supports their inclusion, the agency states.

Second, the FDA issued guidance to the industry on how to submit proof to demonstrate physiological benefits to human health (see the guidance document). Manufacturers with $10 million or more in annual food sales must comply with the new dietary fiber declaration requirements by July 26, 2018; manufacturers selling less than $10 million annually must comply by July 26, 2019.

Seven so far

The FDA determined and was able to assess seven non-digestible carbohydrates that meet its definition of dietary fiber:

  • Beta-glucan soluble fiber (soluble)
  • Psyllium husk (mostly soluble)
  • Cellulose (insoluble)
  • Guar gum (soluble)
  • Pectin (soluble)
  • Locust bean gum (soluble)
  • Hydroxypropylmethcellulose (soluble)

Other fibers, such as inulin, can be added to a product, but they may not be included in the dietary fiber total. Publicly available clinical trial data is also being identified and summarized for non-digestible carbohydrates, including inulin, bamboo fiber, soy fiber, pea fiber, wheat fiber, cotton seed fiber, sugar cane fiber, sugar beet fiber and oat fiber.

Additionally, other fibers are included in the Total Carbohydrate total.

Naturally occurring fibers in foods include those in vegetables, whole grains, fruits, cereal bran, flaked cereal and flours. According to the FDA, fiber is considered to be "intact" in these because the fibers haven't been removed from the food.

The agency has also identified and reviewed an additional 26 types of isolated or synthetic non-digestible carbohydrates, beyond the first seven it already deemed the most common added to food and declared on the Nutrition Facts label as dietary fiber. Interested parties are invited to submit scientific data, information and comments to the FDA on the physiological benefits of the 26 fibers they believe qualify for the fiber definition. Manufacturers who want the agency to amend the definition of dietary fiber to include one of the 26 are asked to submit a citizen petition.

"Unfortunately, the FDA retained the definition of dietary fiber based on a showing of a beneficial physiological effect, rather than a chemical definition, as is the case for most other nutrients," reported the American Bakers Assn. (, Washington. However, the ABA was pleased with other elements of the definition, such as a change in wording, from "isolated and synthetic" fibers to "isolated or synthetic" fiber. "The change helps emphasize fibers that are isolated are not synthetic," according to the ABA.

Defining fibers could also mean some products will be at risk of no longer being eligible for claims and may need to be reformulated to maintain a fiber label declaration.

The American Institute of Baking International (, Manhattan, Kan., considers the FDA's move one of many food-label revisions it envisions coming in the next few years. "There's no analytical test that can differentiate between which fibers have or haven't been determined by the FDA to have physiological benefits," AIB emphasized in its August article examining the definition. "Any product with added fiber will have to be reviewed to determine the declarable dietary fiber amount." Equally important, AIB pointed out, is that the list of acceptable fibers will grow as companies petition to have synthetic or isolated fibers approved.

For carbohydrates lacking physiological studies, guidance will be needed from the FDA on how to conduct the studies, including attributes to measure, number of studies required, the specific population, etc. Studies must show how the fiber behaves in the digestive system, which could take time, delaying new fiber sources from being added to foods launched commercially. But when they are added, there will be definitive proof the fiber is positively contributing to the digestive system. This in tandem with the proposed DRV increase from 25 to 28g needs to be evaluated for all fiber-claiming products in the market and in development.

Thus, a product once considered a "good source" of fiber (10-19 percent of DRV per reference amount customarily consumed) might no longer meet the claim. And the amount of dietary fiber declared on a nutrition label will have to be the total amount of intrinsic fiber, plus approved isolated and synthetic fibers, per serving in the product. All other non-digestible carbohydrates will be included in the carbohydrate declaration, but not in the dietary fiber amount.

What's more, it's up to food companies to keep maintenance records to support the amounts of dietary fiber (as well as added sugars, vitamin E and folate) listed on their labels, as there are no analytical methods that can distinguish the required nutrient definition. As such, the FDA allows food companies and ingredient suppliers to use of electronic databases for analysis. The final rule requires that the records be kept for at least two years after the food is introduced to the market.

"The definition reflects the FDA’s focus of reporting dietary fiber as a proven benefit to human health," observers Blair Brown, regulatory affairs manager at TIC Gums (, White Marsh, Md. "Food producers will now be unable to solely rely on analytical data when determining if a product is considered a fiber. They must now consider the definition when reporting the dietary fiber value. [But] the agency stated that the list of approved fibers is not exhaustive and that additional dietary fibers could be proposed and evaluated via the citizen petition process. The FDA wants to see clinical studies demonstrating that the fiber source has a beneficial end point."

What's next?

Basically, all of this gives ingredient suppliers and food producers more work to do in order to sell and declare an ingredient as a dietary fiber. "The definition will also significantly impact foods promoted as containing substantial levels of dietary fiber, for which the current fiber sources haven't been recognized by the FDA," adds Brown. "In order to maintain dietary fiber's nutritional value, manufacturers will have to replace their current source of fiber with one of the FDA-recognized sources, or file a citizen petition to have their fiber source approved by the agency."

Brown says gum acacia, commonly used as a source of dietary fiber, is on the FDA's list of 26 under review. "To help customers avoid reformulation, we filed a citizen petition and met with the FDA to demonstrate both the intact and intrinsic nature of gum acacia as well as its health benefits, and are awaiting final ruling," Brown explains.

MGP Ingredients (, Atchison, Kan., which also filed a citizen petition in November, says it's sure its patented Fibersym RW and FiberRite RW meet the definition criteria, since they are "isolated non-digestible carbohydrates that demonstrate beneficial physiological effects in humans," says Michael Buttshaw, vice president of ingredients sales and marketing.

"To ensure [the FDA's] vision is met using an orderly and accurate compliance protocol, a timeline extension is needed," adds Rajen Mehta, senior director, specialty ingredients, at Grain Millers' (, Eugene, Ore., office. Mehta views the timeline as inadequate for "such a major regulation. Most food companies will need to establish new formulas, labels and printed packaging by about November 2016 to ensure compliance by July 26, 2018," he says.

"We hope the FDA will respond quickly, because it clearly impacts the industry," concludes Nancy Gaul, senior category manager for health, wellness and dairy, at Tate & Lyle (, Decatur, Ill., regarding her company's petition filing. Other companies are waiting to submit petitions until more information is published about the specifics on scientific evidence companies need in order to meet the new definition.
More information on the definition will be made available through the Federal Register ( and the FDA's website,