How much fiber do you need per day? (and how to get there)
Fiber is one of the nutrients most adults are short on, and in 2025 and 2026 it became a trend of its own, often called "fibermaxxing". Here is what the official targets are, how far off most people are, and which everyday foods close the gap.
The targets
- United States: the Dietary Guidelines for Americans (2020–2025) base fiber on about 14 g for every 1,000 calories you eat. For adults that works out to roughly 22 to 34 g a day: higher for younger adults and for men, lower for older adults and for women.
- United Kingdom: the recommendation for adults is 30 g a day (Scientific Advisory Committee on Nutrition, 2015).
Both are general-population targets for healthy adults. If you eat more calories than average, for example because you train hard, the per-1,000-calorie rule gives you a higher number.
How far off most people are
A 2026 analysis of a decade of the UK National Diet and Nutrition Survey (British Journal of Nutrition) found that adult fiber intake rose but still falls short of the 30 g recommendation. US guidance describes a similar shortfall: most American adults do not meet the fiber recommendation.
Foods that do the most work
Fiber per common serving, from USDA FoodData Central:
| Food | Serving | Fiber | Calories |
|---|---|---|---|
| Split peas, cooked | 1 cup (196 g) | 16.3 g | 231 |
| Lentils, cooked | 1 cup (198 g) | 15.6 g | 230 |
| Pinto beans, cooked | 1 cup (171 g) | 15.4 g | 245 |
| Black beans, cooked | 1 cup (172 g) | 15.0 g | 227 |
| Chickpeas, cooked | 1 cup (164 g) | 12.5 g | 269 |
| Avocado | 1 cup cubes (150 g) | 10.1 g | 240 |
| Chia seeds | 2 tbsp (28.35 g) | 9.8 g | 138 |
| Bulgur, cooked | 1 cup (182 g) | 8.2 g | 151 |
| Raspberries | 1 cup (123 g) | 8.0 g | 64 |
| Blackberries | 1 cup (144 g) | 7.6 g | 62 |
| Artichoke, cooked | 1 medium (120 g) | 6.8 g | 64 |
| Sweet potato, baked | 1 cup (200 g) | 6.6 g | 180 |
| Barley, pearled, cooked | 1 cup (157 g) | 6.0 g | 193 |
| Pear | 1 small (148 g) | 4.6 g | 84 |
| Whole-wheat pasta, cooked | 1 cup (117 g) | 4.6 g | 174 |
| Oats, dry | 1/2 cup (40.5 g) | 4.1 g | 153 |
| Popcorn, air-popped | 3 cups (24 g) | 3.5 g | 93 |
| Brown rice, cooked | 1 cup (202 g) | 3.2 g | 248 |
| White rice, cooked | 1 cup (158 g) | 0.6 g | 205 |
Values are USDA FoodData Central entries for the foods as named, scaled to the serving shown. Brands and cooking change them.
A day that reaches about 30 g
One way to get there without anything unusual:
- Breakfast: 1/2 cup of oats with 1 cup of raspberries: about 12 g
- Lunch: a bowl with 1 cup of black beans: about 15 g
- Snack: a small pear: about 5 g
That's about 32 g before counting vegetables at dinner.
Go up slowly
If you eat around 15 g now, don't jump to 35 g tomorrow. A sudden increase commonly causes bloating, gas and cramping. Add a few grams every few days over two to three weeks, and drink enough water as you do. Variety helps too: different plant foods carry different kinds of fiber.
Track it without weighing everything
Speed Macros shows fiber for every meal you log: type it the way you'd say it ("bowl of oats with raspberries"), and the entry shows its fiber next to calories and protein. The micronutrient tracker adds fiber up across the day against a target based on your calories, and counts how many different plant foods you ate in the past week. If you want foods that bring protein too, see high-protein, high-fiber foods.
This guide is general information for healthy adults, not medical advice. If you have a digestive condition such as IBS or IBD, or have been told to limit fiber, follow your clinician's advice instead.
Sources: Dietary Guidelines for Americans, 2020–2025 (fiber at 14 g per 1,000 calories) · Scientific Advisory Committee on Nutrition, "Carbohydrates and Health", 2015 (30 g a day for adults) · Papagiannaki M, et al. "Changes in food patterns over a 10-year period in the UK adult population; findings from the National Diet and Nutrition Survey." British Journal of Nutrition, 2026. doi:10.1017/S000711452610782X · USDA FoodData Central (SR Legacy entries 172429, 172421, 175200, 173735, 173757, 171705, 170554, 170287, 167755, 173946, 168386, 168483, 170285, 169118, 168910, 173904, 167959, 169704, 168878)