August 2017 Issue

FDA Changes Fiber Definition
By Jessica Levings, MS, RDN
Today's Dietitian
Vol. 19, No. 8, P. 30

Learn about the FDA's new definition of dietary fiber, the controversy surrounding its categorization, and how to counsel clients about labeling changes.

In an effort to make popular packaged foods more healthful, manufacturers in recent years began adding beneficial nutrients to help improve the nutrition profile of certain commonly consumed foods. For example, consumers now can find cereal, oatmeal, and even baked goods with added fiber. However, consumer advocacy groups have expressed concern that these isolated and sometimes synthetic added fibers don't provide the same nutritional benefit as the fiber found in whole plant sources. Until recently, any type of fiber could be isolated from its original source and added to foods, but, in 2016, the FDA finalized a definition of dietary fiber.1 The definition dictates which fibers can and can't be included in the dietary fiber declaration on the Nutrition Facts label, allowing both "intrinsic and intact" plant fiber and certain sources of isolated and synthetic added fiber to be included.

FDA's Fiber Categories
Naturally occurring fiber or "intrinsic" fiber is considered "intact" because it hasn't been removed from the food and is found naturally in foods like vegetables, whole grains, fruits, cereal bran, and flours. The fiber in these foods automatically meets the new definition. However, added fibers—fibers that either have been isolated from their food sources and added to other foods, or are synthetic—can be declared as dietary fiber on food labels only if they meet the "beneficial physiological effect to human health" criterion. The current compliance date is July 26, 2018, for manufacturers with $10 million or more in annual food sales, and July 26, 2019, for manufacturers with less than $10 million in annual food sales. However, the food industry has asked the FDA for a three-year delay to the compliance date for the new food labels. If the outcome of the food labeling regulations is like that of menu labeling, then the food industry likely will see this compliance date pushed back.

According to the FDA, in addition to intrinsic and intact fibers, only the following seven added nondigestible carbohydrates currently meet the new dietary fiber definition:

1. Beta-glucan soluble fiber, also called oat bran fiber, is a soluble fiber found naturally in whole and rolled oats, whole oat flour, oatmeal, and oat bran. It also can be isolated and added as an ingredient to smoothies, yogurt, snack bars, cereals, and other foods to increase fiber content. In 1997, the FDA approved a health claim related to beta-glucan soluble fiber from oats and reduced risk of heart disease.

2. Psyllium husk is a mostly soluble fiber extracted from husks of the Plantago ovata seeds. It can be found as an ingredient in cereals, baked goods, and ice cream.

3. Cellulose is an insoluble fiber added as an ingredient in breads, pancakes, crackers, and frozen breakfast items.

4. Guar gum is a soluble fiber extracted from the endosperm of guar beans that can be found in some coconut and almond milks, cheeses, instant puddings, and gluten-free baked goods, and in fiber supplements (eg, Regular Girl) under the name SunFiber®.

5. Pectin is a soluble fiber isolated from the cell walls of fruits and vegetables. It can be found as an added fiber in foods such as jams, jellies, and dairy products.

6. Locust bean gum is a soluble fiber derived from the seeds of the carob tree that can be found in foods such as breads, sauces, and cereals.

7. Hydroxypropyl methylcellulose is a soluble fiber commonly found in many gluten-free foods.

Before the new definition, there were additional added fibers, such as inulin and wheat fiber, commonly used in foods and that could be labeled as dietary fiber. However, manufacturers must now submit a citizen petition to the FDA providing evidence of a benefit to human health to continue to declare these fibers as dietary fiber on the Nutrition Facts label. If the FDA denies the petition or doesn't respond before the compliance date, manufacturers will have to label the nonapproved fibers solely under "Total Carbohydrate" instead of fiber on the Nutrition Facts label or reformulate their products to include fibers that meet the definition criterion. Many petitions already have been submitted,2 to which the FDA responded that it couldn't come to a decision within 180 days because of "other agency priorities and the limited availability of resources." The FDA has stated that it's "committed to exploring options to address the timing issue" if it's unable to update the list of dietary fibers in time for companies to either relabel or reformulate by the first compliance date.3

Guidance and Controversy
The FDA released a draft guidance explaining the criteria it plans to use to evaluate citizen petitions seeking approval of an added fiber and shared a scientific literature review of the 26 fibers it determined don't meet the definition.4,5 If an added isolated or synthetic nondigestible carbohydrate is the subject of a previously authorized health claim (such as beta-glucan soluble fiber), it's considered to meet the definition.

With average fiber intake at only about 16 g for Americans aged 2 and older,6 consumers are having a hard time meeting the 28 g per day recommendation for fiber intake. Although many Americans aren't meeting fiber intake goals, the International Food Information Council Foundation's 2017 Food and Health Survey found that fiber is top of mind when ranking the healthfulness of food components.7 When asked how they would rate the healthfulness of a list of food components, participants ranked fiber second only to vitamin D, and 87% of participants reported thinking that fiber was healthful.7

The FDA based its fiber definition on the Institute of Medicine's proposed definition of fiber, which defines "dietary fiber" as "nondigestible carbohydrates and lignin that are intrinsic and intact in plants," and "functional fiber" as "isolated nondigestible carbohydrates that have beneficial physiological effects in humans."8 However, according to comments submitted by the Grocery Manufacturers Association, this definition assumes that an inherent physiological benefit of naturally occurring fibers may no longer exist when the fiber is isolated and added to other foods. According to the association, whose comments weren't publically available at press time, "[The] FDA considers the nondigestible carbohydrate in a whole fruit or vegetable to be intrinsic and intact, and thus capable of being labeled as dietary fiber without direct clinical evidence of beneficial physiological effects as a dietary fiber in humans. The logic provided in the Draft Guidance appears to be that such foods provide 'components, such as vitamins and minerals, which may be associated with beneficial physiological effects' even though such effects are not on the list recognized by [the] FDA in the Science Review as being attributable to dietary fiber. It is not scientifically reasonable for the presence of vitamins and minerals, which do not have the same physiological functions as those attributed to dietary fiber, to be factors in determining whether a plant preparation is considered 'intrinsic and intact' or 'isolated.'"

There has, for example, been a degree of controversy surrounding inulin's status as a fiber. Various definitions of dietary fiber have been developed globally by scientific and regulatory agencies, some of which consider inulin a fiber and some of which don't.9 Manufacturers have long used inulin (chicory root) to boost the fiber content of certain products, but when the FDA's new definition was published, it didn't include inulin as an isolated or synthetic fiber with physiological benefits, so the amount of fiber in products coming from this source can no longer be added to the dietary fiber count on the Nutrition Facts label. For example, General Mills' popular Fiber One products contribute 20% to 35% of the current DV of fiber, but the source of fiber in many of the snack bars is isolated chicory root extract. According to General Mills' citizen petition, scientific evidence supports the conclusion that chicory root extract improves laxation (as measured by increased stool frequency) and increases mineral absorption and that each of these are appropriate health benefits to qualify as dietary fiber.10 To date, the FDA has acknowledged the petition but has yet to decide on the outcome.

Industry and Consumer Impact
Manufacturers and ingredient suppliers have been submitting large batches of evidence to the FDA supporting the health benefits of respective fibers on the no-longer-included list, most of which already were assessed by the FDA as part of the scientific evidence review. So how did the FDA come to a different conclusion than the makers and users of these fibers? It may be due to research methodology. The Academy of Nutrition and Dietetics (the Academy) submitted comments to the FDA expressing concern with the methodology used to determine fibers that were included and excluded in the definition. In short, the Academy's comments state, "We share similar concerns of many others that the FDA's guidance would exclude significant evidence from its scientific evaluation of various fibers, because the studies included nonhealthy populations. In addition to the above concerns with conflating the definition of dietary fiber with requirements for health claims, we share concerns with such a restrictive approach when nearly half of Americans are currently living with a preventable chronic disease. Whether the FDA does indeed prepare a grandfather list of fiber sources or it changes its Guidance so as not to unduly exclude studies conducted on nonhealthy populations, it should recognize that the mechanism of action of fiber is fundamentally consistent across populations and thus can be extrapolated to a healthy population when studied in nonhealthy populations."11 The Academy also expressed concern that current fibers would no longer be able to be labeled as fiber, stating, "We also urge the FDA to consider and detail the impact of 'delisting' substances presently understood by consumers, researchers, and manufacturers as dietary fibers." The Academy also expressed concern that current fibers would be labeled as total carbohydrate instead of fiber and suggested that the FDA conduct research related to the impact on consumer understanding surrounding this change.11

While consumer advocacy groups support the change, food manufacturers are having a tougher time. The Center for Science in the Public Interest noted support for the changes, stating in comments to the FDA that it's glad to see that "'fiber' listed on Nutrition Facts labels excludes purified, processed fibers such as maltodextrin and inulin, which are not as beneficial as the intact, unprocessed fiber in whole foods." However, given the negative impact on the food industry, it's no surprise that the Grocery Manufacturers Association "strongly opposes [the] FDA's new definition of 'dietary fiber'" and that the "FDA's review of the scientific evidence of beneficial effects of 26 commonly used fiber ingredients is inadequate and not transparent." The American Bakers Association also submitted a citizen petition asking the FDA to revoke the new definition of dietary fiber and revert to the previous understanding of fiber, and also asked as a second route that the FDA "revise (and correct) the definition" and "immediately stay the new definition."12

Depending on how the FDA modifies the new definition, many of consumers' favorite added fiber products could be reformulated or removed from shelves, or be labeled with less fiber than traditionally has been in the product. Since consumers already were largely underconsuming fiber, they likely will have an even harder time if products with commonly consumed added fiber are no longer available. For example, just one Fiber One Oats and Chocolate snack bar and a 3/4 cup serving of Kashi Go Lean Crunch each contain 9 g fiber, and 140 kcal per bar and 190 kcal per serving, respectively. Consuming both products in one day gets a consumer two-thirds of the way toward his or her fiber intake recommendations, the equivalent of eating four medium apples with the skin, 1 pint of raspberries, 11/4 cups of cooked lentils (at 276 kcal), or 5 cups of cooked whole wheat penne pasta (at more than 700 kcal).13

Recommendations for Dietitians
The 2015–2020 Dietary Guidelines for Americans recommend individuals should aim to meet their nutrient needs through healthful eating patterns including nutrient-dense foods. The Dietary Guidelines also state, "In some cases, fortified foods and dietary supplements may be useful in providing one or more nutrients that otherwise may be consumed in less than recommended amounts." While most dietitians would like to see fiber intake coming from whole, plant-based sources, consuming products fortified with fiber can help clients eat more healthfully if the products fit into a healthful overall eating pattern. Through understanding clients' current eating patterns, RDs can help clients increase their fiber intake by making healthful shifts within food categories. When recommending foods with added fiber, it's important to recommend foods where the added fiber makes a healthful food even better, such as high-fiber whole grain bread or cereal, compared with an unhealthful dessert or sugary breakfast drink, for example, that's had fiber added.

One consideration when counseling clients is that many consumers are actively seeking ingredients they recognize. While chicory root, wheat flour, and rice bran flour sound benign and are mostly recognizable, locust bean gum and hydroxypropyl methylcellulose are unfamiliar and might be avoided if seen on an ingredient list. RDs can help clients learn to read food labels and identify food sources that are higher in fiber. RDs also can market their skills to food companies needing help complying with the fiber definition. Lastly, continuing to encourage clients to eat more fruits and vegetables with the skin on and from all sources, as well as legumes and whole grains, also can help increase fiber intake. However, it's important to keep in mind the calorie contribution of different foods when making recommendations to increase fiber intake to ensure clients aren't exceeding their daily calorie needs.

Sharon Palmer, RDN, author of Plant-Powered for Life and The Plant-Powered Diet, recommends getting a mix of different types of fibers for various benefits and to meet fiber intake recommendations by "eating a variety of whole plant foods such as whole grains, pulses (beans, lentils, peas), vegetables, fruits, nuts, and seeds." According to Palmer, "As dietitians, I think we need to realize that not all people are at this level of eating. When you go from a completely Western diet, it's difficult for many people to make dramatic changes in their diets overnight. That's where we as dietitians can help people; we can assess them where they are and then help them make personalized changes in their diets that will work for them. If it's possible for them to include pulses three times a week, we can start there. If they can make one-half their grain choices whole grain, that's good. Can they fit in a handful of nuts a day? And we may want to help them find particular brands of foods that are high in fiber, such as cereals, breads, and bars. While they may not all have the same benefits as eating whole plant foods, I see it as a small step they can make along their journey."

— Jessica Levings, MS, RDN, is a freelance writer and owner of Balanced Pantry, a consulting business helping companies develop and modify food labels, conduct recipe analysis, and create nutrition communications materials. Learn more at, Twitter @balancedpantry, and


1. Food and Drug Administration, HHS. Food labeling: revision of the nutrition and supplement facts labels. Fed Regist. 2016;81(103):33741-33999.

2. Hyman, Phelps & McNamara PC; Food and Drug Administration. FDA Citizen Petition Tracker.
. Updated July 7, 2017.

3. Questions and answers for industry on dietary fiber. US Food and Drug Administration website. Updated January 6, 2017. Accessed March 8, 2017.

4. Food and Drug Administration, Center for Food Safety and Applied Nutrition. Scientific evaluation of the evidence on the beneficial physiological effects of isolated or synthetic non-digestible carbohydrates submitted as a citizen petition (21 CFR 10.30): guidance for industry.
. Published November 2016. Accessed June 5, 2017.

5. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Nutrition and Food Labeling. Science review of isolated and synthetic non-digestible carbohydrates.
. Published November 2016. Accessed March 8, 2017.

6. US Department of Agriculture, Agricultural Research Service. Table 1. Nutrient intakes from food and beverages: mean amounts consumed per individual, by gender and age, in the United States, 2013-2014. Accessed June 5, 2017.

7. 2017 Food and Health Survey: "a healthy perspective: understanding American food values." International Food Information Council website. Updated June 15, 2017.

8. Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes: Proposed Definition of Dietary Fiber. Washington, DC: National Academy Press; 2001.

9. Jones JM. CODEX-aligned dietary fiber definitions help to bridge the 'fiber gap.' Nutr J. 2014;13:34.

10. Tahiri M; General Mills. A Citizen Petition regarding the inclusion of inulin-type fructans extracted from chicory root in the definition of dietary fiber. Published September 16, 2016. Accessed June 5, 2017.

11. Academy comments to FDA re guidance for scientific evaluation of carbohydrates to be classified as dietary fiber. Academy of Nutrition and Dietetics website. Published February 13, 2017. Accessed March 8, 2017.

12. Covington & Burling LLP; American Bakers Association. Citizen petition and petition for stay of action. Published April 7, 2017. Accessed June 5, 2017.

13. USDA Food Composition Databases. US Department of Agriculture, Agricultural Research Service website. Accessed June 5, 2017.


  • Dietary fiber: nondigestible soluble and insoluble carbohydrates (with three or more monomeric units), and lignin that are intrinsic and intact in plants.
  • Functional fiber: isolated or synthetic nondigestible carbohydrates (with three or more monomeric units) determined by the FDA to have physiological effects that are beneficial to human health.

— Source: FDA


Alginate (soluble fiber derived from brown seaweed)
Apple fiber
Bamboo fiber
Carboxymethylcellulose (cellulose gum)
Corn hull fiber
Cottonseed fiber
Galactooligosaccharides (prebiotic derived from lactose)
Gum acacia
Inulin/oligofructose/synthetic short-chain fructooligosaccharides
Karaya gum
Oat hull fiber
Pea fiber
Polydextrose (synthetic polymer of glucose)
Potato fibers
Pullulan (exopolysaccharide derived from fungus)
Rice bran fiber
High-amylose corn/maize starch (resistant starch 2)
Retrograded corn starch (resistant starch 3)
Resistant wheat and maize starch (resistant starch 4)
Soluble corn fiber
Soy fiber
Sugar beet fiber
Sugar cane fiber
Wheat fiber
Xanthan gum
Xylooligosaccharides (oligosaccharides derived from xylans)

* For a list of where these fibers come from and in what types of foods they're usually found, refer to the FDA's "Science Review of Isolated and Synthetic Non-Digestible Carbohydrates" (

— Source: FDA