Watermelon is one of the healthiest summer treats you can enjoy — it’s hydrating, low in calories, and packed with vitamins A and C, antioxidants, and electrolytes. But even this refreshing fruit can cause problems if you overdo it.
One of the biggest issues is its high water and fiber content. Eating too much at once can overwhelm your digestive system, leading to bloating, stomach cramps, and diarrhea. Watermelon is about 92% water, so consuming large amounts can also flush electrolytes like potassium and sodium from your body, potentially causing imbalances if you’re sensitive.
Watermelon is also high in natural sugar, specifically fructose. While it’s healthier than added sugar, eating too much can spike blood sugar levels, especially for people with insulin resistance or diabetes. For those prone to irritable bowel syndrome (IBS), excess fructose can trigger gas and digestive discomfort.
Another surprising side effect of overindulging? Water retention. Because watermelon contains a significant amount of potassium, overeating may affect kidney function in people with preexisting kidney problems, making it harder to regulate fluid and mineral balance.
So, how much is too much? Nutritionists suggest keeping portions to about two cups per sitting. That’s enough to get all the hydration and nutrients without stressing your digestive system or blood sugar levels.
The bottom line: Watermelon is a summer superfood when eaten in moderation, but polishing off half a melon in one sitting can leave you running to the bathroom, feeling bloated, or messing with your electrolyte balance. Enjoy it as part of a balanced diet — pair it with protein or healthy fat to slow sugar absorption and keep your blood sugar steady. Your body (and your stomach) will thank you.
