Fiber in Food

In 2002, the Food and Nutrition Board of the National Academies of Sciences published a new [Page 457]set of definitions for dietary fiber. Dietary fiber describes the nondigestible carbohydrates and lignin that are intrinsic and intact in plants, while functional fiber consists of the isolated nondigestible carbohydrates that have beneficial physiological effects in humans. Total fiber is the sum of dietary fiber and functional fiber. Nondigestible means “not digested and absorbed in the human small intestine.” Fibers can be fermented in the large intestine or can pass through the digestive tract unfermented. There is no biochemical assay that reflects dietary fiber or functional fiber nutritional status. Blood fiber levels cannot be measured because fiber is not absorbed. No data are available to determine an Estimated ...