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This is what a straight per-100 g sort of the USDA table returns, and it is the list most "highest fiber foods" articles are quietly derived from.

Rank	Food	Fiber per 100 g
1	Corn bran, crude	79.0 g
2	Seed gums (locust bean, guar)	77.3 g
3	Cloud ear fungus, dried	70.1 g
4	Curry powder	53.2 g
5	Cinnamon, ground	53.1 g
6	Savory, ground	45.7 g
7	Wheat bran, crude	42.8 g
8	Rosemary, dried	42.6 g
9	Oregano, dried	42.5 g
10	Coriander seed	41.9 g

Six of those ten are dried spices and one is a thickening gum. Nobody eats 100 g of oregano — a heavy pinch is about half a gram, which is a fifth of a gram of fiber. The numbers are correct and the list is useless.

Ranked by a portion a person would plausibly eat in one sitting. The per-100 g column is the USDA measured value; the per-serving column is that value applied to the standard portion weight given beside it.

Rank	Food	Serving	Fiber per 100 g	Fiber per serving
1	Navy beans, cooked	1 cup (182 g)	10.5 g	19.1 g
2	Split peas, cooked	1 cup (196 g)	8.3 g	16.3 g
3	Lentils, cooked	1 cup (198 g)	7.9 g	15.6 g
4	Pinto beans, cooked	1 cup (171 g)	9.0 g	15.4 g
5	Black beans, cooked	1 cup (172 g)	8.7 g	15.0 g
6	Chickpeas, cooked	1 cup (164 g)	7.6 g	12.5 g
7	Kidney beans, cooked	1 cup (177 g)	6.4 g	11.3 g
8	Chia seeds, dried	2 tbsp (28 g)	34.4 g	9.6 g
9	Green peas, cooked	1 cup (160 g)	5.5 g	8.8 g
10	Bulgur, cooked	1 cup (182 g)	4.5 g	8.2 g

Nine of the ten are legumes. That is the finding, not an artefact of the sorting: legumes are the only common food that is simultaneously high in fiber and eaten by the cupful. A seed with three times the fiber density loses because it is eaten by the spoonful, and a vegetable eaten by the cupful loses because most vegetables are mostly water.

This is the same conclusion the site reaches from the cost side — see Top Ten Most Commonly Eaten Legumes in the World, legume recipes, lentils, and Cheapest Protein and Dry Protein.

Useful if the goal is variety rather than a maximum, or if beans are already covered.

Food	Serving	Fiber per 100 g	Fiber per serving
Raspberries, raw	1 cup (123 g)	6.5 g	8.0 g
Blackberries, raw	1 cup (144 g)	5.3 g	7.6 g
Artichoke, cooked	1 medium (120 g)	5.7 g	6.8 g
Wheat bran, crude	¼ cup (15 g)	42.8 g	6.4 g
Pearl barley, cooked	1 cup (157 g)	3.8 g	6.0 g
Flaxseed	2 tbsp (21 g)	27.3 g	5.7 g
Pear, raw with skin	1 medium (178 g)	3.1 g	5.5 g
Quinoa, cooked	1 cup (185 g)	2.8 g	5.2 g
Broccoli, cooked	1 cup (156 g)	3.3 g	5.1 g
Avocado, raw	½ medium (68 g)	6.8 g	4.6 g
Brussels sprouts, cooked	1 cup (156 g)	2.6 g	4.1 g
Oats, dry	½ cup (40 g)	10.1 g	4.0 g
Sweet potato, baked in skin	1 medium (114 g)	3.3 g	3.8 g
Dried figs	¼ cup (37 g)	9.8 g	3.6 g
Popcorn, air-popped	3 cups (24 g)	14.5 g	3.5 g
Almonds	1 oz (28 g)	12.5 g	3.5 g
Prunes, uncooked	¼ cup (44 g)	7.1 g	3.1 g

• 28 g per day is the FDA Daily Value used on the Nutrition Facts label, based on a 2,000 calorie diet. A "good source" claim requires 10% of that per serving; "high in fiber" requires 20%.
• The underlying Institute of Medicine recommendation is 14 g per 1,000 calories, which works out at roughly 25 g a day for an adult woman and 38 g for an adult man aged 19–50.
• One cup of cooked beans is between 40% and 68% of the Daily Value. That is the entire practical takeaway: a legume a day closes almost the whole gap without changing anything else.

Increase intake gradually and with water. Going from 12 g to 30 g overnight reliably produces bloating and cramping, because the gut bacteria that ferment soluble fiber need a couple of weeks to shift population.

Both matter and most foods carry both, but they do different jobs:

• Soluble — dissolves into a gel. Slows glucose absorption and binds bile acids, which is the mechanism behind the modest cholesterol effect. Oats and oat bran, barley, psyllium, legumes, apples, citrus.
• Insoluble — does not dissolve. Adds bulk and speeds transit. Wheat bran, whole grains, nuts, and the skins and stalks of vegetables.

Chia is the clearest example of why the distinction is visible in the kitchen: its soluble fraction is what turns two tablespoons and a cup of water into a gel. Beans carry a useful amount of both.

• All per-100 g values are USDA measured figures for the food as it is eaten — cooked and drained where the food is cooked, dry where it is not. Dry beans measure roughly 15–25 g per 100 g, but they absorb their own weight in water, so quoting the dry figure against a cooked portion overstates fiber by about half. Several published lists make exactly this error.
• Per-serving figures are computed from the per-100 g value and the standard portion weight shown, then rounded. They are not separately measured.
• "Fiber, total dietary" is what is measured here. It is not the same as net carbs or any proprietary fiber score.
• The site's fiber page is about textile fibre — plant and animal fibres for clothing — not dietary fiber, despite sitting in this folder. The nutrient page is dietary fiber.

dietary fiber · Carbohydrates · Proteins · healthy eating · Nutrition Tables · nutrition and supplements · eating restriction · cheap food staples · legume recipes · lentils · oatmeal · Rye Recipes · Top Ten Most Commonly Eaten Legumes in the World

• USDA National Nutrient Database for Standard Reference Legacy (2018), Total Dietary Fiber (g), abridged list ordered by nutrient content — nal.usda.gov
• FDA, Daily Value on the Nutrition and Supplement Facts Labels — fda.gov
• USDA and HHS, Dietary Guidelines for Americans 2020–2025, food sources of fiber — dietaryguidelines.gov