Fiber + Highest Fiber Foods

The insulin sensitivity fiber foods with the best trial evidence are oats, barley, psyllium, beans and lentils, plus cooked and cooled starches rich in resistant starch. Mostly insoluble fiber has a weaker trial record, though cereal fiber looks protective in long term studies.

The top gel forming fiber foods are psyllium husk, oats and barley for their beta-glucan, and pectin rich fruit like citrus, apricots and berries, with beans and some vegetables close behind. Not every soluble fiber gels, though: inulin and wheat dextrin dissolve without thickening.

The best bulking fiber foods are wheat bran, whole grain cereals and vegetables, whose less fermentable fiber adds about 2 grams of stool weight per gram eaten. Fruit fiber adds less than half as much, because gut bacteria break more of it down.

The best gut bacteria foods are fiber rich plants, especially onions, garlic, leeks, bananas, beans, oats and whole grains, which supply prebiotic fiber your microbes ferment. Fermented foods like yogurt, kefir and kimchi help in a different way, by adding live microbes and raising diversity.

The best slow digesting fiber foods are beans, lentils, chickpeas and barley, which score 24 to 32 on the glycemic index, followed by apples, oranges and rolled oats. Total fiber matters less than you’d think: whole wheat bread digests almost as fast as white.

The best balanced fiber foods give you a solid dose of both soluble and insoluble fiber in one serving: black beans, Brussels sprouts, sweet potatoes, broccoli, apricots, oranges and mango lead the list. Some famous high fiber foods, like kidney beans and raspberries, lean heavily toward one type.

The richest inulin fiber foods are chicory root, salsify, globe artichokes, Jerusalem artichokes and onions, with garlic, leeks, bananas and wheat adding smaller amounts. Chicory root is also where most of the inulin added to packaged foods and supplements comes from.

The best resistant starch foods for everyday eating are beans and lentils, green bananas, and potatoes, rice or pasta cooked and then cooled. Kidney beans tested at about 3.2 grams of resistant starch per 100 grams as eaten, more than most breads and cereals.

The top insoluble fiber foods are wheat bran and bran cereals, whole grains, beans, nuts, berries and vegetables like cauliflower and green beans. A half cup of high fiber bran cereal carries about 14 grams of fiber, half the Daily Value in one bowl.

Corn bran, the outer coat of the corn kernel, has the most fiber of any food skin USDA lists, at 79 grams per 100 grams. Among food skins high fiber picks you can actually eat in normal portions, wheat bran, rice bran and baked potato skin lead the way, while citrus zest and thin fruit peels add smaller amounts.