Fiber is the part of plant foods your body cannot fully digest, and it does a lot of quiet work: feeding gut bacteria, slowing digestion, supporting fullness and helping regulate blood sugar and cholesterol. Here is where to find the most of it, ranked by USDA FoodData Central values per 100 g.
The answer first
By weight, chia seeds are the clear champion at 34.4 g of fiber per 100 g — nothing else common comes close. After that, the best everyday sources are almonds, dry oats and cooked legumes (black beans, lentils, chickpeas). Vegetables and fruits are more modest per 100 g but are so low in calories that you can eat them in volume.
Highest-fiber foods per 100 g
| Food | Fiber (g/100 g) | Calories (per 100 g) | Notes |
|---|---|---|---|
| Chia seeds | 34.4 | 486 | Use by the tablespoon |
| Almonds | 12.5 | 579 | Calorie-dense |
| Rolled oats (dry) | 10.6 | 389 | Per dry weight |
| Black beans (cooked) | 8.7 | 132 | Excellent value |
| Peanuts | 8.5 | 567 | Technically a legume |
| Lentils (cooked) | 7.9 | 116 | High protein too |
| Chickpeas (cooked) | 7.6 | 164 | Versatile |
| Avocado | 6.7 | 160 | Plus healthy fats |
| Walnuts | 6.7 | 654 | Very calorie-dense |
| Whole wheat bread | 6.0 | 254 | vs 2.3 g for white |
| Kale | 3.6 | 49 | Low calorie |
| Carrot | 2.8 | 41 | Easy to eat raw |
| Broccoli | 2.6 | 34 | Low calorie |
| Banana | 2.6 | 89 | Convenient |
| Quinoa (cooked) | 2.8 | 120 | Complete protein |
Seeds and nuts: dense but calorie-heavy
Chia seeds stand alone — over a third of their weight is fiber. But at 486 kcal per 100 g you eat them by the tablespoon (around 5 g), so a realistic serving gives roughly 5 g of fiber for about 70 kcal, which is still excellent. Almonds and walnuts are fiber-rich but very calorie-dense, so portion control matters. See almonds and chia seeds for full breakdowns.
Legumes: the best everyday value
If you want fiber, protein and a low calorie cost together, cooked legumes are hard to beat. Black beans deliver 8.7 g of fiber for just 132 kcal per 100 g, lentils 7.9 g for 116 kcal, and chickpeas 7.6 g for 164 kcal. They also bring iron and potassium. For a head-to-head, see lentils vs black beans. These foods are the backbone of high-fiber, plant-forward eating.
Whole grains beat refined grains
The fiber gap between whole and refined grains is large. Whole wheat bread has 6.0 g of fiber per 100 g versus just 2.3 g for white bread — see the comparison. Dry oats are exceptional at 10.6 g. Choosing the whole-grain version of a staple is one of the easiest ways to lift daily fiber without changing your habits.
Vegetables and fruit: low density, high volume
Most vegetables sit between 2 and 4 g of fiber per 100 g — broccoli 2.6 g, carrot 2.8 g, kale 3.6 g — which looks modest until you remember how few calories they carry. You can eat 300 g of broccoli for about 100 kcal and pick up nearly 8 g of fiber along the way. Fruit is similar: bananas, apples and oranges all hover around 2.4–2.6 g per 100 g, with the bonus of vitamins and being easy to carry.
Practical ways to add fiber
- Swap refined grains for whole-grain versions (bread, pasta, rice).
- Add a tablespoon of chia seeds to yogurt or oats.
- Build meals around beans, lentils or chickpeas a few times a week.
- Eat fruit and vegetables with their skins where edible.
- Increase fiber gradually and drink enough water to avoid discomfort.
A note on accuracy
Fiber values are USDA FoodData Central reference figures per 100 g of edible portion. Methods for measuring fiber differ slightly between datasets, and brand, variety and processing change the numbers. This article is general information, not medical or dietary advice — consult a qualified professional for personal fiber targets. See how to read nutrition data and our methodology.