In this article
- Plums fiber content in fresh, dried and juiced form
- Why drying makes the numbers balloon
- Serving sizes people actually eat
- How plums compare with other fruit
- What happened when adults ate prunes daily
- Sorbitol, the helper that rides along with the fiber
- Sugar, potassium and vitamin K alongside the fiber
- One day of plums, added up two ways
- A quick checklist for more fiber from plums
- One swap to make this week
- Plums and fiber: what people ask
- Sources
Drying a plum takes its fiber from 1.4 grams to 7.1 grams per 100 grams, a fivefold jump. Calories climb at the same pace, so per calorie a fresh plum and a prune are almost exactly tied.
That one quirk shapes everything else about plums fiber content. Two medium fresh plums give you about 2 grams, a quarter cup of prunes gives 3.1 grams, and a cup of prune juice lands at 2.6 grams with far more sugar attached.
Plums fiber content in fresh, dried and juiced form
All three numbers below come from USDA FoodData Central lab records, which list nutrients per 100 grams. Comparing by weight shows how much water each form carries.
| Per 100 grams | Calories | Fiber | Total sugars | Potassium |
|---|---|---|---|---|
| Fresh plums, raw | 46 | 1.4 g | 9.9 g | 157 mg |
| Prunes (dried plums), uncooked | 240 | 7.1 g | 38.1 g | 732 mg |
| Prune juice, canned | 71 | 1.0 g | 16.4 g | 276 mg |
The prune row looks like a different food. It has about five times the fiber, close to four times the sugar and more than four and a half times the potassium of the fresh fruit.
Prune juice sits in a strange middle spot. It holds less fiber per 100 grams than the fresh fruit while carrying more sugar and more calories.
Why drying makes the numbers balloon
A prune is a dried plum. Losing most of its water packs the fiber, sugar and minerals into a smaller, lighter piece of fruit.
Run the numbers per 100 calories and the gap disappears. Fresh plums deliver 3.0 grams of fiber per 100 calories, and prunes deliver 3.0 grams as well (7.1 grams divided across 240 calories works out to 2.96).
Prune juice drops to 1.4 grams per 100 calories, less than half. Cleveland Clinic gastroenterologist Samita Garg, MD, notes that some fiber is lost during the juicing process, which matches what the USDA figures show.
So the form you pick changes how much fiber fits into a handful, not how much fiber you get for each calorie you spend. That distinction matters when you’re choosing between a lunchbox snack and a pantry staple.
Serving sizes people actually eat
Kitchen scales rarely come out for a snack, so these are the portions that show up on labels and in federal nutrition tables:
| Serving | Calories | Fiber | % Daily Value |
|---|---|---|---|
| 2 medium fresh plums (151 g) | 70 | 2 g | 7% |
| 1/4 cup prunes | 105 | 3.1 g | 11% |
| 80 g prunes (the lower trial dose) | 192 | 5.7 g | 20% |
| 1 cup prune juice (256 g) | 182 | 2.6 g | 9% |
The fresh plum row comes from the FDA’s raw fruit label values, which round to whole grams. The quarter cup of prunes comes from the Dietary Guidelines for Americans food source tables, and the last two rows are USDA per 100 gram values scaled to the serving.
The Daily Value for fiber is 28 grams, according to the FDA. An 80 gram portion of prunes is the one serving here that reaches 20% DV, the level the FDA treats as a high source.
Curious how those grams fit into your own day? Our fiber calculator turns your age and calorie needs into a daily fiber goal you can plan around.
How plums compare with other fruit
Fresh plums sit in the middle of the fruit pack. The FDA’s label values for common raw fruits let you line them up per serving and per 100 calories:
| Fruit (FDA serving) | Calories | Fiber | Fiber per 100 calories |
|---|---|---|---|
| Pear (1 medium, 166 g) | 100 | 6 g | 6.0 g |
| Kiwifruit (2 medium, 148 g) | 90 | 4 g | 4.4 g |
| Strawberries (8 medium, 147 g) | 50 | 2 g | 4.0 g |
| Apple (1 large, 242 g) | 130 | 5 g | 3.8 g |
| Orange (1 medium, 154 g) | 80 | 3 g | 3.8 g |
| Peach (1 medium, 147 g) | 60 | 2 g | 3.3 g |
| Plums (2 medium, 151 g) | 70 | 2 g | 2.9 g |
| Banana (1 medium, 126 g) | 110 | 3 g | 2.7 g |
| Grapes (3/4 cup, 126 g) | 90 | 1 g | 1.1 g |
| Sweet cherries (1 cup, 140 g) | 100 | 1 g | 1.0 g |
Plums beat bananas, grapes and cherries per calorie, and tie peaches and nectarines on grams per serving. A single pear, though, gives you three times the fiber of two plums.
Prunes next to other dried fruit
Among dried fruits, prunes trail a little. The Dietary Guidelines list a quarter cup of dried figs at 3.7 grams for 93 calories and a quarter cup of prunes at 3.1 grams for 105 calories.
The true fiber heavyweights are elsewhere in the produce aisle. One cup of guava gives 8.9 grams and one cup of raspberries gives 8.0 grams, over four times what two fresh plums supply.
What happened when adults ate prunes daily
A UK research team ran one of the cleanest tests of prunes and digestion. They split 120 healthy adults who ate little fiber and had 3 to 6 bowel movements a week into three groups for four weeks.
- Group one ate 80 grams of prunes a day with 300 mL of water.
- Group two ate 120 grams of prunes a day with the same water.
- The control group drank only the 300 mL of water.
Stool weight rose by 22.2 grams a day in the 80 gram group and 32.8 grams a day in the 120 gram group, while the control group barely moved (minus 0.8 grams). Bowel movements in the 80 gram group reached 6.8 a week, against 5.4 for controls.
Whole gut transit time didn’t change, and stool consistency scores didn’t differ between groups. Flatulence did climb in the prune groups, an honest trade-off the authors reported.
The study team estimated prunes at about 6 grams of fiber per 100 grams, so the smaller dose supplied close to 5 grams a day. That modest amount still made a measurable difference in people starting from a low fiber diet.
Sorbitol, the helper that rides along with the fiber
Fiber gets most of the credit, but prunes also carry sorbitol, a sugar alcohol found naturally in the fruit. Cleveland Clinic explains that sorbitol helps relieve constipation by drawing water into the colon.
This is why prunes punch above their fiber count. Cleveland Clinic’s Dr. Garg says five dried prunes are roughly equal to a half cup of prune juice, and she prefers the whole fruit because of its higher fiber.
The same doctor also warns that overdoing prunes or prune juice shows up fast, with gas, bloating or diarrhea. Her advice is to begin with just a few prunes or a small drink and see how your body responds.
If your digestion runs on the slow side most weeks, our gut health guides lay out how to build a routine around foods like prunes without the surprises.
Sugar, potassium and vitamin K alongside the fiber
Fiber is only one line on a plum’s nutrition panel. The rest changes a lot depending on the form you choose.
- Sugar: two fresh plums carry 16 grams, all naturally occurring, while 100 grams of prunes carry 38.1 grams and a cup of prune juice about 42 grams.
- Potassium: two fresh plums provide 230 mg, and 100 grams of prunes provide 732 mg, about 16% of the 4,700 mg Daily Value.
- Vitamin K: 100 grams of prunes supply 59.5 micrograms, about half the 120 microgram Daily Value.
Cleveland Clinic lists potassium and vitamin K among the nutrients prunes contribute.
One day of plums, added up two ways
Picture a late summer weekday when plums are cheap and piled high at the market. You eat two fresh plums with breakfast and two more as an afternoon snack.
That’s 4 grams of fiber for 140 calories, about 14% of your Daily Value. It’s a useful contribution, though not a fiber plan on its own.
Now swap the afternoon pair for a quarter cup of prunes stirred into plain yogurt. The day’s plum total rises to 5.1 grams for 175 calories, and the prunes bring sorbitol as a bonus.
Replace the yogurt prunes with a glass of prune juice and the total falls to 4.6 grams for 252 calories. You spent 77 more calories than the prune version and got half a gram less fiber.
Looking for more ways to cook with prunes and fresh plums, from oatmeal toppings to roasted plum desserts? Our recipe eBooks are stocked with easy high fiber ideas for every season.
A quick checklist for more fiber from plums
- Count two fresh plums as about 2 grams, not a full serving of fiber.
- Use prunes when you want more fiber in less space, since a small handful beats a pile of fresh fruit by weight.
- Pair plums with a higher fiber partner, such as a pear or a spoonful of raspberries, to clear 5 grams at one snack.
- Pick whole prunes over prune juice for fiber, keeping juice for times you want the sorbitol effect in a drink.
- Start with a few prunes a day and work up, since gas is the side effect the prune trial reported.
- Drink water alongside, as the prune trial paired every dose with 300 mL.
One swap to make this week
Trade one packaged snack for about 80 grams of prunes, weighed once on a kitchen scale so you learn what the portion looks like. That single serving brings you to 20% of your daily fiber goal, the dose that raised stool weight in the UK trial.
Keep it at that amount for a week before going higher, and drink a glass of water with it. If the week goes smoothly, you’ve found a fruit habit that does more work than its fresh form could on the same snack plate.
Plums and fiber: what people ask
How much fiber is in one plum?
About 1 gram. The FDA lists 2 medium plums (151 grams) at 2 grams of fiber and 70 calories, so one plum gives roughly half of that.
Do prunes have more fiber than plums?
Yes, by weight. Prunes have 7.1 grams of fiber per 100 grams against 1.4 grams in fresh plums, although per 100 calories both land near 3 grams.
Does prune juice have any fiber?
A little. One cup of canned prune juice has about 2.6 grams of fiber and 182 calories, so whole prunes give you more fiber for fewer calories.
How many prunes should you eat a day for fiber?
A trial in healthy adults used 80 to 120 grams of prunes a day, which supplied about 5 to 7 grams of fiber. Starting with a few prunes and building up helps limit gas.
Are plums good for digestion?
Yes, modestly. Fresh plums add about 1 gram of fiber each, while prunes add more fiber plus sorbitol, which Cleveland Clinic says draws water into the colon.
Can prunes cause gas?
Yes. Flatulence rose in the prune groups of a four week trial, and Cleveland Clinic notes that eating too many prunes can bring gas, bloating or diarrhea.
Which fruit has more fiber than plums?
Many do. A medium pear gives 6 grams, a large apple 5 grams and a cup of raspberries 8 grams, against 2 grams for two fresh plums.
Sources
- U.S. Department of Agriculture, Agricultural Research Service. “Plums, raw (169949); Plums, dried (prunes), uncooked (168162); Prune juice, canned (167753).” FoodData Central, SR Legacy. 2019. fdc.nal.usda.gov
- U.S. Food and Drug Administration. “Raw Fruits Poster (Text Version / Accessible Version).” 2023. www.fda.gov
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. “Food Sources of Dietary Fiber.” Dietary Guidelines for Americans, 2020 to 2025. www.dietaryguidelines.gov
- U.S. Food and Drug Administration. “Daily Value on the Nutrition and Supplement Facts Labels.” 2024. www.fda.gov
- Lever E, Scott SM, Louis P, Emery PW, Whelan K. “The effect of prunes on stool output, gut transit time and gastrointestinal microbiota: A randomised controlled trial.” Clinical Nutrition. 2019. aura.abdn.ac.uk
- Cleveland Clinic. “Does Prune Juice Help Relieve Constipation?” Health Essentials. 2023. health.clevelandclinic.org
