Dietary fiber, also called roughage, includes the parts of plant-based foods that the body cannot digest or absorb. It can be broadly categorized into soluble fiber and insoluble fiber. Soluble fiber dissolves in water to form a gel-like material in the digestive system. Oats, peas, beans, apples, citrus fruits, carrots, barley, and psyllium are good sources of soluble fiber. It helps lower blood cholesterol and regulates the blood sugar levels. Insoluble fiber is a type of fiber that does not dissolve in water and promotes the movement of stool through the digestive system. It is found in whole-wheat flour, wheat bran, nuts, beans, and in vegetables such as cauliflower, green beans, and potatoes. Insoluble fiber adds bulk to the stool and prevents constipation. The book aims to shed light on the nutritional function of dietary fibers in promoting human health. Its extensive content provides the readers with a thorough understanding of the subject.