Fiber: The Nutrient Most People Are Missing
It fills you up, feeds your gut and lowers cholesterol, and most Americans get only about half of what they need. Here's how to fix that without a stomachache.
The short version
- Aim for about 25 grams a day for women and 38 grams for men, or a little less after age 50. Most people get around 15.
- Fiber helps you feel full and is linked to lower heart disease, diabetes and colorectal cancer risk.
- Beans, lentils, whole grains, vegetables, fruit, nuts and seeds are the best sources.
- Increase it slowly and drink more water, or you'll feel it.
Why it matters
Fiber is the part of plant food your body can't fully digest. It does a lot on its way through:
- Keeps you full. It adds bulk and slows digestion.
- Steadies blood sugar. Particularly soluble fiber.
- Lowers LDL cholesterol. Soluble fiber binds to it in your gut.
- Keeps you regular. Insoluble fiber helps move things along.
- Feeds gut bacteria. They ferment it into compounds that seem to benefit your health.
Two kinds
- Soluble: Dissolves into a gel. Oats, beans, lentils, apples, citrus, barley, psyllium.
- Insoluble: Adds bulk. Whole wheat, nuts, cauliflower, green beans, potato skins.
Most plant foods contain both, so you don't need to keep them straight.
Top sources
| Food | Fiber |
|---|---|
| Lentils, 1 cup cooked | About 15 g |
| Black beans, 1 cup cooked | About 15 g |
| Chickpeas, 1 cup cooked | About 12 g |
| Raspberries, 1 cup | About 8 g |
| Pear, 1 medium | About 5 to 6 g |
| Oatmeal, 1 cup cooked | About 4 g |
| Whole-wheat pasta, 1 cup cooked | About 5 to 6 g |
| Broccoli, 1 cup cooked | About 5 g |
| Chia seeds, 1 tablespoon | About 4 g |
| Almonds, 1 oz | About 3.5 g |
| Baked potato with skin | About 4 g |
| White bread, 1 slice | Under 1 g |
An easy 30-gram day
- Breakfast: Oatmeal with raspberries and chia seeds (about 13 g)
- Lunch: Lentil soup with a side salad (about 10 g)
- Snack: A pear (about 5 g)
- Dinner: Whole-wheat pasta with lots of vegetables (about 6 g or more)
How to increase it without pain
Going from 15 grams to 35 grams overnight will cause gas, bloating and cramps. Instead:
- Add about 5 grams a day each week.
- Drink more water alongside it.
- Rinse canned beans, which reduces some of the gas-causing compounds.
- Be patient. Your gut bacteria adjust over a few weeks.
Supplements
Whole foods are best, as they come with other nutrients. But a supplement can fill the gap, and psyllium has the best evidence for cholesterol and regularity. Take it with plenty of water, and leave a gap of a couple of hours from medications, since it can affect how well they're absorbed.
Sources
This guide is general information, not medical advice. Please check with a clinician before making big changes, especially if you have a health condition, take medication, or are pregnant. Read the full disclaimer.
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