In fact, dietary fiber is the focus of two FDA-approved health claims that appear on foods labels touting the benefits of high fiber foods for the prevention of heart disease and certain types of cancer. Since the early 1950's, when the term "fiber" first began to be used in scientific journals, there has been considerable controversy among food scientists, nutritionists, and medical experts about
the exact definition of dietary fiber. In fact, even the United States Food and Drug Administration, the federal agency responsible for overseeing food labeling, has no formal, written definition of dietary fiber. For food labeling purposes and the determination of health claims, the FDA has adopted the analytical methods that the Association of Official Analytical Chemists uses for defining dietary fiber. Although most experts agree that a key defining characteristic of dietary fiber is that it's derived from the edible parts of plants that are not broken down by human digestive enzymes, many people believe that this definition is too ambiguous and that a more clear, internationally-accepted definition is needed to ensure that the total fiber counts on food labels are consistent and accurate. In recent years there has been a movement among various organizations to include the physiological benefits of dietary fiber in a new definition. For example, the American Association of Cereal Chemists proposed a new definition of dietary fiber that includes the statement "Dietary fibers promote beneficial physiological effects including laxation and/or blood cholesterol attenuation and/or blood glucose attenuation." In addition, the Institute of Medicine at the National Academy of Sciences (the organization responsible for issuing Recommended Dietary Allowances) has proposed a new definition that differentiates between dietary fiber and added fiber. According to this definition, dietary fiber consists of nondigestible carbohydrates and lignin that are intrinsic and intact in plants. Added fiber, which refers to fiber that is added to foods during food processing, consists of isolated nondigestible carbohydrates that have proven beneficial physiological effects in humans. For food labeling purposes, the Institute of Medicine defines Total Fiber as the sum of Dietary Fiber and Added Fiber. Despite the controversy surrounding the exact definition of dietary fiber, experts agree on one important thing - dietary fiber is an important weapon in the fight against heart disease, colon cancer, diabetes, and obesity. Categories of Dietary Fiber
Cellulose, found in bran, legumes, peas, root vegetables, cabbage family, outer covering of seeds, and apples
Hemicellulose, found in bran and whole grains
Polyfructoses (Inulin and Oligofructans)
Galactooligosaccharides
Gums, found oatmeal, barley, and legumes. Mucilages
Pectins, found in apples, strawberries, and citrus fruits
Lignin, found in root vegetables, wheat, fruits with edible seeds (such as strawberries)
Resistant Starches, found in ripe bananas, potatoes
