Kiwifruit for Constipation: 2 Green Kiwis a Day Added About 1.5 Bowel Movements a Week

If you are going to try kiwifruit for constipation, three questions decide whether it is worth the effort: how many, for how long, and whether it is safe for you. In the largest trial so far, 184 people ate two green kiwifruit a day for four weeks, and the ones with constipation had about 1.5 more complete bowel movements per week than at baseline. This guide turns that trial, and a second smaller one, into a plan you can follow and measure.

How many kiwifruit, and for how long

The number comes straight from the trials, so it is worth being exact about what each one tested.

A “complete spontaneous bowel movement” is one that happens without a laxative and leaves you feeling empty. It is the measure both trials used, and it is a better target than “how often I go,” because a rushed, incomplete trip does not count.

Four weeks is the length both trials ran for each treatment. If you are trying kiwifruit on your own, it is reasonable to give it about that long before deciding it does or does not suit you.

Green or gold

The larger 2023 trial used green kiwifruit, two a day. The 2019 trial used a gold variety (a cultivar called Zesy002), three a day. They are different fruits at different doses, so the results are not interchangeable. A 2022 scoping review of 12 clinical trials with 661 participants found good evidence that green kiwifruit may reduce abdominal discomfort and pain, and some evidence for indigestion. It examined gold and green, but its abstract does not declare a winner.

The practical reading: if you can find ripe green kiwifruit, start with two a day, since that is the dose from the biggest study. If you prefer gold, the smaller trial used three, so you would need to eat more of it to match what was tested.

How to eat them: ripeness, skin, water

The trial abstracts do not spell out preparation details, so the points below are common-sense kitchen advice rather than trial findings. Treat them as defaults you can adjust.

• Ripeness: a kiwifruit that gives slightly under a gentle squeeze is ripe. Hard ones are sour and harder to eat in quantity, which matters when the plan is two or three a day. Leave them on the counter for a few days to soften.
• Skin: the skin of green kiwifruit is edible and adds fiber, but it is fuzzy and many people dislike it. Rinse well and rub off the fuzz if you want to try it. Eating the flesh alone is fine, and the skin was not what the trials tested.
• Water: fiber works better with fluid. Have a glass of water with your kiwifruit and keep drinking normally through the day.
• Timing: the abstracts do not say what time of day participants ate them. Pick a slot you can repeat, such as breakfast or an afternoon snack, because consistency is easier to track.
• Ramping up: if your usual fiber intake is low, extra gas for a few days is common. Starting with one a day for the first week and moving to two is a gentle way in. This is a practical suggestion, not a tested protocol.

What to expect, and how to track it

The honest expectation is a shift, not a transformation. In the 2023 trial the average gain over baseline was around 1.5 extra complete bowel movements a week for people with constipation. In the 2019 trial, people went from about 3 to about 6 a week. Averages hide individual spread, so some people will do better and some will notice little.

A simple way to find out whether it works for you is to count. Use a notes app or a paper calendar and mark each bowel movement that felt complete and happened without a laxative.

Comfort matters as well as frequency. In the 2023 trial, gut-comfort scores measured on a validated scale improved in constipated participants. The 2022 review pooled five trials that used that scale and found an average drop of 0.85 points in abdominal pain scores and 0.33 in indigestion scores with habitual kiwifruit intake. If your bloating eases even when your count barely moves, that is still a real result.

Why it may work

Researchers point to several features. A 2021 review of kiwifruit chemistry notes that the fruit contains dietary fiber, vitamins, polyphenols and a protease, which is a protein-digesting enzyme. The review lists “promote gut health” among its biological activities. The trials, though, measured outcomes, not mechanisms, so the “why” remains a reasonable hypothesis rather than a settled explanation.

That same review is also careful in the other direction: it states that clinically significant effects of kiwifruit on preventing or treating major chronic diseases are not yet evident. Constipation relief is the best-supported use. A 2024 meta-analysis of six trials found kiwifruit lowered LDL cholesterol by about 9 mg/dL but found no significant changes in weight, blood sugar or inflammation markers. So this is a fruit with a decent track record for one thing, not a cure-all.

If kiwifruit alone is not enough

Constipation has many causes, and a single fruit will not fix all of them. If your count barely moves, consider these next steps, in this order:

1. Check your overall fiber intake. Many people eat far less than recommended. Our guide to how much fiber is too much lays out the targets and a sensible way to ramp up.
2. Compare with a fiber supplement. Psyllium was the comparator in both trials. For how the fruit and the powder stacked up in a head-to-head design, read our breakdown of the kiwifruit versus fiber supplement trial.
3. See someone. If it has lasted weeks despite diet changes, a clinician can check for causes that food will not solve, including medicines you take.

If bloating and cramps are your main complaint rather than infrequency, see our look at what the trials show about peppermint oil for IBS.

Who should skip or ask first

• Kiwi or latex-fruit allergy. Kiwifruit is a known allergen, and a 2021 review lists allergens among the chemical hazards of the fruit. Itching or tingling in the mouth or throat is a reason to stop. Swelling, wheezing or trouble breathing is an emergency.
• If you have been told to limit potassium or sugar, for example with kidney disease or diabetes, ask your clinician how much fruit fits your plan before adding two or three a day.
• Red-flag symptoms. Blood in the stool, black stools, severe or worsening abdominal pain, unexplained weight loss, vomiting, or a sudden change that lasts more than a couple of weeks all need a medical evaluation, not a fruit experiment.
• Children and pregnancy. The trials described here enrolled adults. Ask a pediatrician or your prenatal clinician about constipation in those situations.
• Bowel narrowing or recent abdominal surgery. Ask before raising fiber from any source.

A note on the research: Zespri, a kiwifruit marketing company, funded or took part in both trials, and some authors are its employees or have received grants from it. The trials are still randomized and peer reviewed, but independent replication would strengthen the case. The 2019 trial was small (32 people) and single-blind.

Questions people ask

This article is for education only and is not medical advice. Talk to a qualified clinician before changing your diet if you have a medical condition or take medication.