A fiber is a natural or artificial substance that is significantly longer than it is wide, often in the form of thin threads or filaments used to make materials like cloth, rope, or composites
. Fibers can be derived from plants, animals, minerals, or synthesized artificially. For example, natural fibers include cotton, wool, silk, and asbestos, while synthetic fibers include materials like carbon fiber and rayon
. In nutrition, fiber refers specifically to a type of carbohydrate found in plant foods that the human body cannot digest or absorb
. Dietary fiber is the indigestible part of plant-based foods such as fruits, vegetables, whole grains, legumes, nuts, and seeds. It passes through the digestive system mostly intact, aiding digestion and promoting health by supporting bowel regularity, weight management, and reducing risks of diseases like diabetes, heart disease, and some cancers
. There are two main types of dietary fiber:
- Soluble fiber: dissolves in water, can be fermented by gut bacteria, and helps regulate blood sugar and cholesterol levels.
- Insoluble fiber: does not dissolve in water, adds bulk to stool, and helps prevent constipation
In summary, a fiber can mean:
- A threadlike structure used in manufacturing and materials (natural or synthetic)
- A carbohydrate component of plant foods that aids human digestion and health by being indigestible
