Insoluble fiber or “roughage” is necessary for digestive health and promoting regular bowel movements. Most fiber-rich foods offer a combination of insoluble and soluble fiber, with an emphasis on the insoluble. Insoluble fiber food sources are exclusively plant products. Foods particularly high in insoluble fiber include bran cereals and certain whole grains, legumes, fruits and vegetables.
Bran Cereals
Ready-to-eat bran breakfast cereals are high in insoluble fiber. Of the following cereals, all but 1g of the dietary fiber content listed for each comes from insoluble fiber. A 1/2-cup serving of General Mills Fiber One cereal provides 14g dietary fiber. The same serving size of Kellogg’s Original All-Bran (buds) offers 10g dietary fiber. They have a higher-fiber version which offers 3 more grams for the same serving size. A 1-cup serving of Benefit Nutrition Simply Fiber ready-to-eat cereal offers 14g dietary fiber and a 1/2-cup serving of Quaker Kretschmer Toasted Wheat Bran provides 14g dietary fiber. A 100-gram serving of Wheatabix wheat biscuits provides 9g insoluble fiber.
Whole Grains and Flours
Insoluble fiber content for the following grains and flours is listed for a 3.5-ounce serving. Wheat bran (raw, crude) is the food product highest in insoluble fiber content, providing a whopping 36g. Oat bran is rich in insoluble fiber as well, providing 16.7g. Rye products, such as rye bran, flakes, malt and flour all provide 11.4g while rye crisp bread offers nearly 13g. Whole grain wheat flour (100 percent whole wheat) provides 9g and white soy meal offers 8g. Popcorn, one of the most popular and tasty whole grain foods, offers 7.2g insoluble fiber.
Legumes
A 3.5-ounce serving of beans, white or brown, offers 13.5g insoluble fiber. Starchy beans are also a good food source of soluble fiber. Peanuts, also a legume, salted or unsalted, provide nearly 8g insoluble fiber. A 1/2-cup serving of lentils, green or brown, provides 7g insoluble fiber.
Dried Fruits
Exotic dried fruits, such as papaya, mangos, or peaches all provide approximately 7g per 3-oz. serving.
Nuts and Seeds
A 3.5-ounce serving of whole almonds provides 7g insoluble fiber. Sesame seeds (with hull), sunflower seeds, prunes without pits and raisins round out the best food sources of insoluble fiber, each providing roughly 6.4g per 3.5-ounce serving.
About this Author
Michele Turcotte is a registered, licensed dietitian, and a certified personal trainer with the National Academy of Sports Medicine. She has more than 12 years of experience in clinical and corporate settings, and has extensive experience in one-on-one diet counseling and meal planning. She has written freelance food and nutrition articles for Trouve Publishing Inc. since 2004.
