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The following is an update and revision of an article originally posted August 22, 2016. With recent FDA approvals of several non-digestible carbohydrates as dietary fiber, it was necessary to update the list of approved dietary fibers and change the example in the article.
Under the final rule for updates to the nutrition facts panel published by the Food and Drug Administration (FDA) in May of 2016, one of the major changes was the definition of dietary fiber. Some ingredients were defined as dietary fiber in the final rule, but numerous substances were left out of the definition and could not be counted as dietary fiber in the nutrition panel.
Dietary fiber is a mandatory nutrient on Nutrition Labels and both the amount of dietary fiber per serving and the Percent Daily Value (%DV) must be declared on the label. With the Final Rule published by the FDA in May 2016, the Daily Reference Value (DRV) has changed from 25g to 28g and there is now a definition for the nutrient “dietary fiber”. The FDA has defined dietary fiber as “non-digestible soluble and insoluble carbohydrates (with 3 or more monomeric units) and lignin that are intrinsic and intact in plants; isolated or synthetic non-digestible carbohydrates (with 3 or more monomeric units) determined by the FDA to have physiological effects that are beneficial to human health”.
There is no analytical test that can differentiate between the non-digestible carbohydrates that have or have not been determined by the FDA to have physiological benefits, so any product with added non-digestible carbohydrates will have to be reviewed to determine the declarable dietary fiber amount. Under the FDA’s new rule, non-digestible carbohydrates and lignin that exist naturally in plants will be included in the dietary fiber on the nutrition label. The biggest change is that only the isolated or synthetic non-digestible carbohydrates that the FDA has determined to be beneficial to human health will be included in the dietary fiber declarations on the label. As seen in the chart to the right, the FDA initially approved 7 types of isolated or synthetic non-digestible carbohydrates as meeting the new definition of dietary fiber.
In June of 2018, the FDA published a guidance document that states their approval of 8 additional types of non-digestible carbohydrates as dietary fiber. These are provided in the chart to the left. The category “Mixed Plant Cell Wall Fibers” is comprised of many different substances. The FDA provided the following as examples of this category: apple fiber, bamboo fiber, barley fiber, carrot fiber, citrus fiber, cocoa fiber, corn fiber, corn hull fiber, cotton seed fiber, oat hull fiber, pea hull fiber, pea seed coat fiber, inner cotyledon pea fiber, rice bran fiber, soy hull fiber, soy polysaccharide fiber, soy cotyledon fiber, sugar beet fiber, sugar cane fiber and wheat fiber.
Not all substances under review were approved. Notably, gum acacia and xanthan gum did not meet the definition based on the evidence reviewed. Some petitions are still under review and some substances have not yet been submitted. For instance, Xylooligosaccharides are structurally different than fructooligosaccharides and inulin so Xylooligosaccharides will have to be reviewed separately. Companies are able to petition the FDA to have other synthetic or isolated non-digestible carbohydrates approved, but they must demonstrate that these substances have beneficial physiological effects.
Dietary fiber is considered part of the total carbohydrates in nutrition labels in the US. The amount of dietary fiber declared on the nutrition label will be the total amount per serving of intrinsic and intact fiber plus isolated or synthetic non-digestible carbohydrates that have been determined to have beneficial physiological effects. All other non-digestible carbohydrates will be included in the total carbohydrate declaration but will not be included in the dietary fiber amount. In addition, the %DV for fiber will have to be recalculated using the new amount per serving that meets the definition of dietary fiber and the new 28g DRV for dietary fiber. These two changes may have an impact on label claims currently being made about dietary fiber. A product that was considered to be an “excellent source” of dietary fiber (20% or more of DRV per reference amount customarily consumed or RACC) might not meet that claim anymore.
If I have a product with 3 ingredients that are sources of non-digestible carbohydrates, how would the dietary fiber declaration on my label change? Each of the 3 ingredients is contributing 2g of non-digestible carbohydrates per serving. The first ingredient is wheat fiber, the second ingredient is inulin, and the third ingredient is xylooligosaccharides. The following shows how your nutrition panel and claims would be affected. (Assume that the serving size on the panels is the same as the RACC amount.)
Only 2 of the 3 sources of non-digestible carbohydrates will meet the FDA’s new definition of dietary fiber. Xylooligosaccharides are not yet considered isolated or synthetic fiber with physiological benefits, so the 2g of non-digestible carbohydrates coming from them cannot be added to the dietary fiber declared on the label. The 2g of non-digestible carbohydrates from the wheat fiber and the 2g of non-digestible carbohydrates from the inulin are approved as dietary fiber so they can be included in the declaration on the panel. You may have noticed that the amount of total carbohydrates does not change with the new label. This is because all 3 types of non-digestible carbohydrates are still considered carbohydrates.
The new regulations mandate that certain records must be kept for at least 2 years after introduction of the food or delivery for introduction of the food into interstate commerce. Upon request, these records must be provided to the FDA. These records can be kept in a variety of ways including databases, recipes, formulations, or batch records. When dietary fiber, soluble dietary fiber, or insoluble dietary fiber is mixed with non-digestible carbohydrates that do not meet the definition of dietary fiber, the manufacturer must make and keep written records of the amount of non-digestible carbohydrates that do not meet the definition are being added. Again, this is because analytical methods cannot distinguish between the non-digestible carbohydrates that meet the definition and those that do not. For the above example, you would need to provide records showing that the food has 2g of non-digestible carbohydrates from the wheat fiber and 2g of non-digestible carbohydrates from the inulin that both meet the definition of dietary fiber and has 2g of non-digestible carbohydrates from xylooligosaccharides that do not meet the definition.
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