fiber food sources

Whole-wheat flour, wheat bran, nuts, beans, and vegetables, such as cauliflower, green beans and potatoes, are useful sources of insoluble fiber. The amount of soluble and insoluble fiber varies in different plant foods. To receive the greatest health benefit, eat a wide variety of high-fiber foods.

Another article on Healthline lists some other high-fiber foods such as berries, cruciferous vegetables, oats, chia seeds and dark chocolate.