Watermelon is a nutrient-rich food that’s mostly made of water. Eating it can support hydration and healthy digestion. It’s also a good source of fiber, which helps move food through your digestive tract (the tube that moves food through the body) and keeps good bacteria in your gut balanced.
Eating watermelon can help encourage easier and more regular bowel movements. The fruit is about 93% water by weight, supporting healthy hydration in your digestive tract and throughout your body. Proper hydration can help soften stools (poop) and make them easier to pass.
Research suggests that 95% of Americans aren’t meeting their daily fiber needs. Watermelon is also a good source of fiber. One wedge (about one-sixteenth) of a watermelon provides 1.14 grams (g) of fiber. Even a small amount of fiber can add bulk to your stool and help it pass through your intestines. Including watermelon in a well-balanced diet may help prevent constipation and improve overall gut health.
Some people may experience side effects on their bowel movements when eating too much watermelon. Consuming a lot at once may cause an upset stomach or diarrhea, especially in people with sensitive gastrointestinal (GI) systems. This is because watermelon has fructose, a type of sugar that isn’t easily digested.
Other Digestive Effects
Watermelon can affect digestion in good and bad ways, depending on your digestive system and medical history.
Some people experience GI symptoms after eating watermelon because it’s high in fructose, which is hard to digest. When fructose isn’t digested in the small intestine, it passes through to the colon (large intestine), where bacteria break it down. This process can create gas buildup, leading to bloating, stomach pain, and diarrhea.
Those with a history of irritable bowel syndrome (IBS) can be especially sensitive to fructose. Eating watermelon may worsen and make it more challenging to manage flare-ups.
Even those without a history of GI conditions can experience discomfort if they eat too much watermelon. Eating small portions and monitoring your tolerance level may be beneficial to avoid these unwanted symptoms.
While watermelon is generally safe for the average healthy adult, some people may need to limit or avoid it in their diet. Those who may need to be cautious with their watermelon intake may include people with:
- IBS: Watermelon may cause digestive distress in people with a history of IBS.
- Inflammatory bowel disease (IBD): The fiber in watermelon can make flare-ups from gastrointestinal conditions such as ulcerative colitis or Crohn’s disease worse.
- A fructose intolerance: Watermelon contains fructose, a sugar found in fruit that can cause GI discomfort, bloating, or loose stool in those who may not digest it easily.
- A fluid-restricted diet: Watermelon is 93% water by weight, which may add to the amount of fluid in your body. This can negatively affect people who may need to avoid having additional fluids.
- Sensitive stomachs: Some individuals may experience gas and other GI challenges after eating too much watermelon.
- Diabetes: Watermelon has a moderate amount of sugar, and eating too much may raise blood sugar levels.
- Kidney disease: Someone with a history of chronic kidney disease or end-stage renal disease may need to be cautious when consuming watermelon. Research suggests that watermelon can increase potassium levels, and the kidneys may not be able to filter out the excess electrolytes.
- Allergy or sensitivity: People who are allergic or have a sensitivity to watermelon should avoid consuming it.
Gastrointestinal responses to foods will vary person to person. If you aren’t sure if watermelon is right for you, talk with your doctor or registered dietitian. A registered dietitian is a healthcare professional who has special training in diet and nutrition.
Because nutrition isn’t one-size-fits-all, there is no standard serving size for watermelon. Eating two cups of watermelon every day is generally safe and well-tolerated for the average healthy adult. Two cups of watermelon provide just under 2 grams of fiber and about 22 grams of carbs.
Watermelon can be a healthy addition to a well-balanced diet for most people. Talk with a registered dietitian to make sure it’s safe to add to your diet. They can help you decide if watermelon is an appropriate snack, and if so, how much to eat in one sitting.
