Grandma called it roughage , today we call it fiber . Fiber has become a household word and high fiber foods are being promoted in many grocery stores. However, interest in fiber is not a recent development. Fiber will not cure or prevent all diseases, but it should be a part of a healthy diet.
Most fibers are carbohydrates.
Our bodies cannot digest them. Thus the fiber portion of the food does not contribute calories to the diet. There are different types of fiber in your diet - cellulose, hemicellulose, pectin, gums and lignin. Different plants have different types of fiber. The fiber in oats for example, is different from the fiber in celery.