ABSTRACT
Dietary fiber is an umbrella term for a heterogeneous mixture of plant food components that are indigestible in the small intestine. The dietary fiber hypothesis implies that a high intake of fiber-containing foods is directly related to, or is associated with, a low incidence of many disorders and diseases common with a Western lifestyle. Dietary fiber is available in the human diet through a wide variety of food sources, such as both raw and processed cereals, vegetables, legumes, and fruits. Experts in paleolithic nutrition have theorized that primitive diets contained high levels of dietary fiber. The modern era of dietary fiber research began in the 1950s, and interest in it has steadily gained momentum. The most concentrated sources of dietary fiber are whole grains and cereal brans. Refining processes decrease the fiber content in grains. The most common form of dietary fiber is insoluble fiber.
