Is Watermelon Good for You?

This juicy summer fruit packs plenty of health benefits

sliced triangles of watermelon on a cutting board with a whole watermelon next to it Photo: Huizeng Hu/Getty Images

Some love plump peaches. Others wait all year for cherry season. And you can’t deny the appeal of fresh berries. But for many people, watermelon is the fruit that epitomizes summer. It’s a staple at picnics and backyard barbecues, and Americans eat more than 14 pounds of it per person per year. The fact that it’s sweet, refreshing, and inexpensive compared with other summer fruits (the national average price is 60 cents a pound, according to the latest data from the Department of Agriculture) is probably what makes it popular. But watermelon is good for you, perhaps more than you realize.

Watermelon Health Benefits

“As with all fruits and vegetables, watermelon is very nutritious, and it’s quite delicious,” says Lisa Sasson, MS, RD, clinical professor of nutrition at New York University. “As its name implies, it’s mostly water [92 percent] and is a great way to hydrate yourself in the warmer weather.” You can even use it as a post-workout snack to replenish fluids lost during exercise, she says.

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At just 40 calories, a cup of watermelon will give you about 13 percent of the daily value of vitamin C and small amounts of calcium, iron, magnesium, potassium, and vitamin A.

However, the nutrient watermelon is most known for isn’t a vitamin or a mineral, Sasson says, but a phytonutrient called lycopene—a powerful antioxidant that gives the fruit’s flesh its characteristic reddish-pink hue. Antioxidants help fight free radicals, which can cause cell damage. “Like all phytonutrients, lycopene appears to protect against some cancers, such as prostate cancer and breast cancer,” Sasson says. “It may also help protect against heart disease.”

In fact, watermelon is unique in that it’s one of the few foods that are packed with this pigment. Tomatoes, pink and red grapefruit, and guava are among the other lycopene-rich foods. According to the USDA, watermelon has an average of about 40 percent more lycopene than raw tomatoes (although cooked tomato products are the best source). The redder and sweeter the flesh, the more nutritious the melon, the USDA says. 

Beyond lycopene, USDA researchers have identified 1,500 phytonutrients in watermelon, many of which have anti-inflammatory properties. It is also uniquely rich in a compound called L-citrulline, which can help relax blood vessels, thereby improving blood flow and helping to control blood pressure.

You Can Eat Watermelon Rind and Seeds

Watermelon seeds and rind are typically discarded, but they’re edible and highly nutritious. Using them cuts down on food waste and is good for the environment.

Like other seeds, watermelon seeds are rich in healthy fats and protein, plus they’re a decent source of iron, magnesium, and zinc. You may have a hard time finding a seeded watermelon, though, because 90 percent of what’s grown in the U.S. these days is seedless.

The seeds’ flavor is reminiscent of sunflower seeds, but a little less nutty. Watermelon rind tastes a little like cucumber (watermelon and cucumber are from the same botanical family) and is crunchy like jicama. It’s even higher in citrulline than the flesh, plus it provides about 14 grams of fiber per ounce.

How to Pick a Watermelon

Watermelons ripen only slightly after harvest, so you want to make sure the one you buy at the store or farm stand is ready to eat. You could use the thump test—knock on the melon and listen for a dull, hollow, muffled sound. But a better, and more reliable, approach is to look for a watermelon that’s heavy for its size, has a smooth surface, a slightly dull rind, filled in and rounded ends, and a yellow or creamy yellow underside.

Whole melons will keep seven to 10 days unrefrigerated. That timing accounts for harvesting and shipping to the grocery store; a locally-grown melon may last longer. Cut melon should be refrigerated and eaten in three to four days.

Watermelon Safety

From a food safety perspective, buying a whole melon is better than buying a container of precut watermelon. It may be a time-saver, but precut melon (not just watermelon, but other melons as well) have been linked to several foodborne illness outbreaks. In commercial facilities, many fruits and vegetables are processed in one place, creating opportunities for cross-contamination.

When you buy a whole watermelon, wash it before slicing into it, because the outside can be contaminated with harmful bacteria, such as salmonella, Sasson says. If bacteria is present, the knife can carry it from the rind to the flesh as you slice. Always be sure to use a clean knife so that you don’t inadvertently transfer bacteria from other foods to the melon.

What You Can Do With Watermelon

Eat watermelon fresh off the rind, mix it into a cold tomato-watermelon gazpacho, or crush it into juice. You can freeze watermelon chunks or crushed watermelon to make ice cubes to use in drinks or smoothies, or partly freeze it to make a cool, refreshing, slushy treat.

You can also spice it up with salt, pepper, lime, or chili as a snack or to add to a salad. Try combining watermelon with peaches, mint, a little feta cheese, and farro for a summery whole-grain dish. Or, leaving the rind on, grill wedges (about 2 minutes per side) to caramelize the fruit’s sugars, and serve plain or with a sauce made from honey, garlic, and chili oil or chili crisp.

Toast watermelon seeds and add to salads or in place of pumpkin or sunflower seeds in recipes. The rind can be used in a variety of ways (cut the green parts off before cooking). Recipes from the Watermelon Board suggest grating it and using it in place of cabbage in a coleslaw, roasting it and topping with Parmesan, or slicing and including it in a stir-fry to add some crunch.