A Closer Look at the FDA's Definition of Dietary Fiber

This text has been updated on 8/29/16

There are lots of revisions to food labels in the next few years. One of the major changes to nutrition labels is the definition of dietary fiber in the final rule published by the Food and Drug Administration (FDA) in May 2016.

How has the new FDA rule changed dietary fiber?

Dietary fiber is a mandatory nutrient on nutrition labels. 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 now a definition for the nutrient, dietary fiber appears. 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”.

What does this mean?

There is no analytical test that can differentiate between which fibers have or have not been determined by the FDA to have physiological benefits. So any product with added fiber 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 fibers 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 above, the FDA has, so far, approved 7 types of isolated or synthetic non-digestible carbohydrates as meeting the new definition of dietary fiber. It is important to remember that this list will be growing as the FDA approves other types of fiber. Companies are able to petition the FDA to have other synthetic or isolated fibers approved, but they must demonstrate that these substances have beneficial physiological effects.

How will this affect the label?

Dietary fiber is 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 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 will not be included in the dietary fiber amount. In addition, the %DV for fiber will have to be recalculated using the new amount that meets the definition of dietary fiber and the new 28g DRV for dietary fiber. These two changes will have an impact on label claims currently being made about dietary fiber. A product that was considered to be a “good source” of dietary fiber (10-19% of DRV per reference amount customarily consumed or RACC) might not meet that claim anymore.


If I have a product with three ingredients that are sources of non-digestible carbohydrates, how would the dietary fiber declaration on my label change?

Each of the three ingredients is contributing 2g of non-digestible carbohydrates per serving. The first ingredient is inulin, the second ingredient is wheat fiber, and the third ingredient is cocoa. The graphic below explains how a nutrition panel and claims would be affected. 

(Assume that the serving size on the panels is the same as the RACC amount.)

What causes the change?

Only 1 of the 3 sources of non-digestible carbohydrates meets the FDA’s new definition of dietary fiber. Inulin is not yet considered an isolated or synthetic fiber with physiological benefits, so the 2g of fiber coming from inulin cannot be added to the dietary fiber count. The fiber in wheat is naturally occurring, but when it is separated from the other parts of the kernel it becomes an isolated fiber. This source of non-digestible carbohydrates has not been approved as fiber by the FDA. The 2g of fiber coming from the cocoa is the only amount of dietary fiber that 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 since all 3 types of non-digestible carbohydrates are still part of the total carbohydrate amount. This product cannot make a dietary fiber claim since the %DV is now 7% and a minimum of 10% is needed.

What records must be kept?

The new rule requires keeping certain records 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 being added. Again, this is because analytical methods cannot distinguish between the ones that meet the definition and those that do not. For the given example, you would need to provide records showing: the food has 2g of dietary fiber from the cocoa, it meets the definition of dietary fiber, has 4g of non-digestible carbohydrates from inulin, and wheat fiber that do not meet the definition.

With all the new FDA changes, there is no better time to reserve your seat at our Foundations: Labeling of FDA Regulated Foods or Specializations: Advanced Labeling of FDA Regulated Foods seminars to learn about the latest regulatory changes. These courses are sure to sell out as the industry prepares for the most sweeping regulatory labeling changes in the last two decades. Can't make the seminar? Our new $99 webinar will help you make the transition to FDA's new nutrition facts label.

Email or call us at 800-633-5137 with your labeling questions.

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