Dietary fiber is a complex group of substances that can be categorized according to their source, solubility, fermentability (how effectively bacteria metabolize them), and physiological effects.
Different forms of dietary fiber include:
- Non-starch polysaccharides (hemicellulose): Found in cereal grains; present in both soluble and insoluble forms
- Pectin: water-soluble polysaccharide; Highest amounts found in fruit and to a lesser degree in vegetables, legumes, and nuts
- B-glucans: non-starch polysaccharide, generally soluble; Highest amounts found in barley and oats
- Cellulose: major component of plant cell walls; found in grains, fruits, and to a lesser degree in vegetables and nuts
- Lignin: Found in foods with a woody component aka celery and the outer layer of cereal grains (The outer layer is the bran, which is the part that is removed during processing, but remains intact in whole grains)
I think most people could agree that we should be getting more plants into our diets, but does anyone really know why? Yes, eating more whole plant foods, like fruit, vegetables, legumes, and whole grains can help reduce our risk of chronic disease—thank you phytochemicals! But what really is the deal with plants? Why is it so important that we eat them on a regular basis? One word. FIBER.