Watermelon Nutrition Facts and Health Benefits

by OneGoodFoodBlog
Watermelon Nutrition Facts and Health Benefits

Watermelon, one of summer’s most iconic fruits, is low in calories and rich in water. It’s also an excellent source of vitamins A and C and lycopene while being less acidic than citrus fruits and tomatoes—other well-known providers of lycopene and vitamin C.

Watermelon Nutrition Facts

One cup of diced watermelon (152g) provides 46 calories, 0.9g of protein, 11.5g of carbohydrates, and 0.2g of fat. Watermelon is an excellent source of lycopene and vitamins A and C. The following nutrition information is provided by the USDA.

  • Calories: 46
  • Fat: 0.2g
  • Sodium: 1.5mg
  • Carbohydrates: 11.5g
  • Fiber: 0.6g
  • Sugars: 9.4g
  • Protein: 0.9g
  • Vitamin C: 12.3mg
  • Vitamin A: 42.6mcg
  • Lycopene: 6890mcg


The carbohydrates in watermelon are mostly sugars, with only a little fiber. Half of the sugar is fructose, one quarter is glucose, and less than one quarter is sucrose, with other sugars making up minor fractions.1 If you are counting carbohydrates, it’s best to measure watermelon carefully.

  • 1 cup diced watermelon (152g): 0.6 grams fiber, 9.4 grams sugars, 11.5 grams total carbohydrates, 10.9 grams net carbohydrates
  • 1 medium-sized wedge of watermelon (286g): 1.1 grams fiber, 17.7 grams sugars, 21.6 grams total carbohydrates, 21 grams net carbohydrates

Watermelon has a glycemic index (GI) of 76.2 This means it could give you a faster rise in blood sugar than foods with a lower GI. However, when considering glycemic load (which takes into account how much you eat per serving), a half cup of chopped watermelon is 4, which is considered low.


You will get almost no fat in watermelon, making it similar to other melons such as cantaloupe or honeydew. The fat that is present is mainly polyunsaturated (0.076 grams), with smaller amounts of monounsaturated (0.056 grams) and saturated (0.024 grams) fatty acids.

For dietary tracking purposes, you can consider watermelon a non-fat food. The seeds (yes, they are edible) are a source of omega-3 fatty acids.


Watermelon has only a little protein, with just under 1 gram per cup. Interestingly, some companies produce watermelon seed protein by sprouting and shelling the seeds.

You won’t be able to get that level of protein from fresh seeds, however, because the shell of the seed prevents digesting the protein inside.

Vitamins and Minerals

A fully ripe red watermelon contains higher levels of nutrients than less ripe watermelon. A single serving of watermelon is a good source of vitamin C and vitamin A, providing a significant percentage of your daily requirement for each.

Vitamin C aids in wound healing and may have anti-aging and immune-boosting properties, whereas vitamin A is important for eye health. A one-cup serving of watermelon also provides about 7% of your daily needs of copper and pantothenic acid, 5% of biotin, and 4% of vitamins B1 and B6.


One cup of diced or balled watermelon contains around 46 calories. If you prefer to eat it wedged instead, a wedge that is around one-sixteenth of the melon (286 grams) contains almost double that amount or approximately 86 calories.


Watermelon is low in calories and contains almost no fat. While providing many valuable nutrients—such as vitamins A and C—it is somewhat high in sugar, so people who are monitoring their sugar intake may be best served by eating this fruit in moderation.

Health Benefits

Beyond being a sweet summer treat, watermelon can boost your health in several ways.

Fights Dehydration

Aptly named, watermelon is almost 92% water, making it a very hydrating food choice. If you or your children struggle to drink enough water—especially on hot summer days—try a few servings of watermelon. You’ll get extra micronutrients along with your hydration.

Reduces Blood Pressure

Watermelon has antioxidant power because it is an excellent source of lycopene, a carotenoid phytonutrient that research has shown may help reduce or prevent high blood pressure. Tomatoes are well known as a source of lycopene, but a fully ripe watermelon has even more lycopene than a tomato.

Reduces Risk of Infections and Cancer

Other antioxidants in watermelon include flavonoids, carotenoids, and triterpenoids. Antioxidants such as these assist in cell repair and may help lower your risk of infections and some cancers.

Contributes to Weight Loss

In a small study of overweight adults, those who consumed watermelon instead of low-fat cookies felt more full. They also showed reductions in body weight, body mass index, waist-to-hip ratio, and blood pressure.

Helps Ease Muscle Fatigue

The amino acid citrulline is present in significant amounts in watermelon. You can find capsules of concentrated citrulline sold as a nutritional supplement for sports performance. The benefits of citrulline are not conclusive, although some studies show that citrulline supplements might reduce the feeling of fatigue during exercise.


Watermelon food allergies are rare. However, if you have hay fever or are allergic to ragweed pollen or grasses, you may have a food-pollen allergy syndrome which may lead to a cross-reaction to the proteins in watermelon that are similar to the pollen.

This reaction might feel a tingling or itch in your mouth after eating watermelon. In rare cases, this can be more serious and trigger throat swelling or anaphylaxis.

Adverse Effects

Watermelon poses few risks, with research deeming this fruit “nontoxic without known side effects.” However, because it does contain sugar, people with diabetes may need to be cautious when eating watermelon to avoid blood sugar spikes.


Watermelon comes in dozens of varieties and cultivars. These can be grouped by size (“icebox” or smaller varieties vs. larger “picnic” types), the color of their flesh (pink, yellow, or orange), and whether they contain seeds or are seedless.

Watermelon has a thick rind that can be solid green, green-striped, or mottled with white. Melons can be round or oval in shape and typically weigh between 6 pounds and 29 pounds. The crisp flesh is mostly pinkish-red, although golden-fleshed varieties are becoming more popular.

Native to tropical Africa, watermelons are grown commercially in the U.S. in areas such as Texas, Florida, Georgia, and California, where the weather is warm and conducive to a long growing season.

When It’s Best

Watermelon is in season in summer in the U.S. A ripe watermelon is one that feels heavy for its size. The outside should be firm and free of nicks or dents. The ground spot—where the melon was resting on the ground—should be a creamy yellow color as opposed to white.

Storage and Food Safety

Fresh, uncut watermelon can be stored at room temperature. Heat will cause the flesh to dry out, so if it’s hot outside, watermelon should be kept in a cool place like a cellar or the refrigerator.

Uncut watermelon can be stored in the refrigerator for two to three weeks. Once you cut it, you can keep it in the fridge for up to five days if it is in a closed container or sealed plastic bag. You can also freeze watermelon that’s been cut up into chunks.

How to Prepare

Go beyond typical slices and add watermelon to smoothies, salsa, and salads (both fruit salads and veggie-heavy ones, too). Its subtle sweetness also pairs well with cheese, nuts, and other protein sources.

You can also grill or freeze watermelon for a tasty dessert. Place cold or frozen watermelon chunks into water or seltzer for a tasty, low-calorie beverage.

The whole watermelon is edible. You can eat the seeds as well as the rind, the latter of which is sometimes turned into watermelon rind flour or served after being stir-fried, stewed, or pickled. (The white seeds in a seedless watermelon are actually empty seed coats that did not fully mature.)

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