What is dietary fiber and why do you need fiber



What is dietary fiber and why do you need fiber

Although most people are aware of the role fiber plays in helping to maintain good health, questions remain as to the best types of fiber, how much is needed, and how it works. Here are some of the answers:

What is fiber and where is it found?

Simply defined, fiber is the structural part of plants – the framework that supports and holds a plant together. Sometimes called roughage or bulk, fiber is a strandlike material that cannot be digested by the human stomach because it is resistant to digestive enzymes. It can, however, be partly digested by some bacteria in the lower intestines. Although the term “fiber” suggests a solid or string-like substance, much of our dietary fiber is more in the nature of a gelatin or mucilage.

Fiber is found only in plant foods such as fruits and vegetables, beans, and grains. Plants contain different kinds and amounts of fiber, depending on the species, the variety, the growing conditions, the age of the plant when harvested, and the degree to which it has been processed. Fiber is made up of the nondigestible carbohydrates and carbohydratelike components cellulose, hemicellulose, pectin, and lignin.

The amount of fiber found in foods is of ten expressed as “crude fiber,” a scientific measurement of the organic material left after chemical digestion of food in the laboratory. Because this process digests much more than the natural chemical digestion that occurs in the body, most experts prefer the measure expressed as “total dietary fiber,” which is usually two to three times higher than crude fiber.