Resistant Starch - As Functional Fiber

As Functional Fiber

Resistant starch is considered both a dietary fiber as well as a functional fiber, depending on whether it is naturally in foods or added. The U.S. Institute of Medicine has defined total fiber as equal to functional fiber plus dietary fiber, and U.S. food labeling doesn't distinguish between them.

In 1971, Painter and Burkitt suggested that a significant gap exists between the amount of dietary fiber urbanized people consume and the optimal amount of fiber for health and wellness, but some skepticism remains. In 1982, Englyst et al. gelatinized starch then post-processed it with both alpha-amylase and pullulanase in order to analyze it, found that some starch remained, and called it resistant starch. In 1986, Berry formed functional RS3 dietary fibers by a process of heating and cooling a variety of starch sources, one of which was amylopectin pre-processed with the enzyme pullulanase. That source had the second highest alpha-amylase resistant starch level, while amylomaize or high-amylose starch had the highest. In 2007, the Federal Register published a 2001 U.S. Institute of Medicine (IOM) Panel on the Definition of Dietary Fiber's response to a request from the U.S. Food and Drug Administration. The IOM Panel proposed two definitions: functional fiber as "isolated, nondigestible carbohydrates that have beneficial physiological effects in humans", and dietary fiber as "nondigestible carbohydrates and lignin that are intrinsic and intact in plants." They also proposed that the prior classifications of soluble versus insoluble be phased out and replaced with viscous versus fermentable with respect to each specific fiber.

The National Academy of Sciences of the Institute of Medicine within the United States has recommended a daily fiber intake of 38 grams for adult men and 25 grams for adult women. Many countries around the world recommend 25-30 grams for their populations.