Fiber is a type of carbohydrate that cannot be digested by humans. There are two main types - soluble and insoluble fiber. Soluble fiber acts like a sponge in the digestive system while insoluble fiber acts like a brush. Fiber is important for maintaining healthy glucose and cholesterol levels and regular bowel movements. The recommended daily fiber intake is 25-30 grams per day for females and 38 grams for males. Good sources of fiber include fruits, vegetables, legumes, whole grains, nuts and seeds. Getting enough fiber is linked to reducing the risk of diseases like cancer, heart disease and diabetes.