The main function of fiber in the diet is to aid in digestion and maintain regular bowel movements. There are two types of fiber: soluble and insoluble. Soluble fiber helps lower cholesterol and regulate blood sugar, while insoluble fiber adds bulk to the stool and promotes digestive health. Additionally, fiber contributes to a feeling of fullness, which can assist in weight management by preventing overeating. Incorporating fiber-rich foods into the diet, such as fruits, vegetables, and whole grains, is important for overall digestive health and helps reduce the risk of chronic diseases.