Best Foods for Constipation: 12 Foods That Actually Help
2026-09-04 · By the Diet for Constipation data editorial team · 1,671 words
The best foods for constipation share one recipe: plenty of fiber, enough water to keep that fiber comfortable, and — in a few standout cases — a natural sugar alcohol that pulls water into the gut. Prunes, kiwifruit, raspberries, pears, oats, barley, lentils, black beans, green peas, air-popped popcorn, whole-wheat bread, and broccoli are the twelve foods that clear every bar in our rating system. All twelve carry a green rating, every number below comes from USDA source data, and none of it requires anything exotic from the supplement aisle.
A note on method first, because it shapes every pick: we rate foods, not nutrients in isolation. A food earns green when its fiber density holds up at a portion a person would actually eat, when its water content works with the fiber rather than against it, and when nothing in its processing profile raises a flag. That last bar is why a fiber number alone can mislead — a low-moisture snack with 3 g of fiber is not a constipation strategy. Here are the twelve, grouped by how they earn their place.
The four fruits that do the most work
1. Prunes — 7.1 g of fiber per 100 g, plus sorbitol
Prunes are the reference point for a reason. Dried plums combine 7.1 g of fiber per 100 g with 14.7 g of sorbitol, a sugar alcohol that draws water into the colon the way a gentle osmotic would — a one-two punch no other common fruit matches. A pitted cup weighs 174 g, more than 12 g of fiber, but you do not need that much: four to five prunes with a glass of water is the classic starting portion. Randomized trial data backs the reputation, which we unpack in our full prune verdict.
2. Kiwifruit — 3.0 g per 100 g, with trial results behind it
Green kiwifruit looks modest at 3.0 g of fiber per 100 g until you notice the portion: a sliced cup weighs 180 g, which lands near 5.4 g — and kiwifruit brings 83 g of water per 100 g along for the ride. Two green kiwis a day is the dose used in clinical studies; we lay out the trial record next to prunes and psyllium in our deep dive.
3. Raspberries — 6.5 g per 100 g, the quiet overachiever
One cup of raspberries (123 g) delivers roughly 8 g of fiber for about 65 calories — among the best fiber-per-calorie trades in the produce aisle. The seeds are not a defect; they are part of the fiber. And the frozen bag keeps the number, which matters in the winter months when fresh berries get expensive.
4. Pears — 3.1 g per 100 g, skin on
A cup of pear slices (140 g) carries about 4.3 g of fiber, and a meaningful share of it lives in the skin, so peeling works against you. Pears also contain sorbitol in modest amounts — less than prunes, but it adds up inside a piece of fruit you can eat in minutes.
Grains and legumes: the bulk-builders
5. Oats — 10.6 g per 100 g dry
Dry rolled oats carry 10.6 g of fiber per 100 g, and the 40 g that makes a normal breakfast bowl contributes about 4 g before you add a thing. Oats also bring soluble fiber that dissolves into a soft gel — the same mechanism that makes psyllium husk work, delivered in breakfast form.
6. Barley, hulled — 17.3 g per 100 g dry
The highest-fiber grain in our green zone. A quarter-cup of dry hulled barley (about 46 g) adds roughly 8 g of fiber to a soup or pilaf. Pearl barley is the easier find in most stores and still respectable; the hulled version is the number you see here.
7. Lentils — 10.7 g per 100 g dry
Dry lentils run 10.7 g of fiber per 100 g, and a cooked cup lands near 15 g — roughly half of most adults' daily target in one side dish. They are also the cheapest item on this list, which matters when the goal is an everyday habit rather than a one-week experiment.
8. Black beans — 15.5 g per 100 g dry
The densest legume in our ratings at 15.5 g per 100 g dry. One standard piece of advice applies: build up across a couple of weeks and pour water alongside, because a sudden legume ramp-up trades one kind of discomfort for another.
9. Whole-wheat bread — 6.0 g per 100 g
A commercial slice (32 g) contributes about 1.9 g — modest on its own, but it replaces a white slice at 0.8 g, and the swap repeats at every meal of the week. Compounded over a week of sandwiches, that difference starts to matter.
10. Air-popped popcorn — 14.5 g per 100 g
The surprise on the list. Three cups of air-popped popcorn (24 g) run about 3.5 g of fiber for under 100 calories. The number collapses when the same popcorn is drowned in butter and caramel, so the preparation is part of the rating, not a footnote.
The supporting cast
11. Green peas — 5.7 g per 100 g
A cup of fresh peas (145 g) carries about 8.3 g of fiber; the frozen version lands near 6 g and costs a fraction of the price. Frozen peas are the rare vegetable where the freezer aisle is nutritionally indifferent — the numbers barely move between the two.
12. Broccoli — 2.6 g per 100 g
Not the densest pick, but a chopped cup (91 g) adds 2.4 g of fiber alongside 89 g of water per 100 g and a plate's worth of vitamin C. Dinner is where consistency is won, and broccoli anchors a plate the way snacks cannot.
Three yellow-rated foods that still earn a place
Chia seeds (34.4 g of fiber per 100 g), flaxseed (27.3 g), and almonds (12.5 g) all rate yellow in our system. The fiber numbers are spectacular — but the calories are dense, and the classic mistake is overdoing a very good thing. A teaspoon of chia stirred into the oats, a small handful of almonds, a tablespoon of ground flaxseed: that is the working dose. The spoon, not the bag.
What a day on this list looks like
Breakfast: a 40 g bowl of oats with a sliced kiwifruit and a teaspoon of chia — about 9 g of fiber before the coffee is poured. Lunch: a lentil-and-vegetable soup with a whole-wheat roll — another 10 g or more. Snack: three cups of air-popped popcorn or a cup of raspberries — 3.5 to 8 g. Dinner: a barley pilaf with broccoli — call it 6 to 8 g. That is a 28-to-35 g day built entirely from ordinary food, roughly double what the average American adult actually manages.
The twelve, at a glance
| Food | Fiber / 100 g | Reference portion | Fiber in that portion |
|---|---|---|---|
| Prunes, dried | 7.1 g | 1 cup pitted (174 g) | 12.4 g |
| Kiwifruit, green | 3.0 g | 1 cup sliced (180 g) | 5.4 g |
| Raspberries | 6.5 g | 1 cup (123 g) | 8.0 g |
| Pears, raw | 3.1 g | 1 cup slices (140 g) | 4.3 g |
| Oats, dry | 10.6 g | 1 cup (156 g) | 16.5 g |
| Barley, hulled, dry | 17.3 g | 1 cup (184 g) | 31.8 g |
| Lentils, dry | 10.7 g | 1 cup (192 g) | 20.5 g |
| Black beans, dry | 15.5 g | 1 cup (194 g) | 30.1 g |
| Green peas | 5.7 g | 1 cup (145 g) | 8.3 g |
| Whole-wheat bread | 6.0 g | 1 slice (32 g) | 1.9 g |
| Popcorn, air-popped | 14.5 g | 1 cup popped (8 g) | 1.2 g |
| Broccoli, raw | 2.6 g | 1 cup chopped (91 g) | 2.4 g |
Portions are the reference servings in our rated database; grains and legumes are dry weights, which cook up to larger, softer servings.
FAQ
Which food works fastest for constipation?
Prunes are the usual answer, and not only for the fiber: their sorbitol content draws water into the gut, so many people notice a difference within a day of the four-to-five prune starting portion. Kiwifruit is the other fast actor with trial support — two green kiwis a day was the studied dose. Both work best alongside a glass of water.
Is oatmeal good for constipation?
Yes. Dry oats carry 10.6 g of fiber per 100 g, so a normal 40 g breakfast bowl contributes about 4 g before toppings. Its soluble fiber forms a soft gel that eases stool passage — the same mechanism behind psyllium. The topping choice decides the rest: kiwifruit or raspberries push the bowl further; sugar does not.
How much fiber should I aim for in a day?
Public-health targets sit at about 25 g a day for adult women and 38 g for men, while the typical American intake hovers around half of that. If your current number is low, climb gradually over two to three weeks and drink water with the extra fiber — a sudden jump usually causes gas and cramping before it causes regularity.
Do I need prunes specifically, or is any dried fruit fine?
Other dried fruits carry real fiber, but prunes are the only one with the sorbitol bonus on top, and they are the dried fruit with randomized trial data behind them. Dates and dried figs are reasonable backups; raisins land further behind. The full comparison of fiber and sorbitol is in our prune verdict.
Sources
- USDA FoodData Central — fiber, water, and portion weights for all twelve foods (entries as rated in our rule library)
- Kiwifruit and prune trial evidence: see our prune verdict and kiwifruit vs. prunes vs. psyllium deep dive for study identifiers
- Fiber intake targets: Institute of Medicine, Dietary Reference Intakes (25 g/day adult women, 38 g/day adult men)
This article is informational only, based on published research and USDA data. It is maintained by our data editorial team — not medical professionals. Nothing here is medical advice.