Watermelon is about 92 percent water and provides vitamin C and the antioxidant lycopene.
Nutrition
Two cups of diced watermelon (300 g) provide about 92 calories, 1.2 g of fiber, 23 mg of vitamin C, 865 IU of vitamin A and about 13 mg of lycopene (USDA).
Hydration
Watermelon is about 92 percent water.
Benefits
- Lycopene is an antioxidant, linked in studies to heart health.
- Citrulline may improve blood flow and reduce muscle soreness.
- Vitamin C and potassium.
Cautions
It has a high glycemic index (72) but low glycemic load. People with FODMAP sensitivity may get gas.
Tip
Choose a heavy melon with a yellow field spot.
Safety
Wash rinds before cutting.
Storage
Cut melon: refrigerate up to 3 to 5 days.
Nutrition data
Two cups (about 300 grams) of diced watermelon have about 90 calories, 22 grams of carbohydrate, 18 grams of sugar, 1 gram of fiber and 2 grams of protein. It provides 25% of the daily value of vitamin C, 10% of vitamin A and 8% of potassium, along with magnesium and vitamin B6. Watermelon is about 92% water by weight.
Hydration
Water content makes it a helpful contributor to hydration in hot weather, with each cup supplying about 140 milliliters of water plus electrolytes like potassium. Watermelon juice has been studied as a sports recovery drink.
Benefits
- Lycopene: watermelon has about 4.5 to 6.5 milligrams per 100 grams, more than fresh tomatoes by weight. Lycopene is an antioxidant studied for heart and prostate health.
- Citrulline: an amino acid that converts to arginine and then nitric oxide, which relaxes blood vessels. Small trials show watermelon extract lowered blood pressure in adults with prehypertension and may reduce muscle soreness after exercise.
- Low calorie, high volume food that aids fullness and weight management.
- Vitamin C and A support immunity, skin and vision.
- Cucurbitacin E and other compounds are being researched in labs.
Cautions
- Sugar: a moderate glycemic index of 72, but a low glycemic load of about 5 per serving because it is mostly water. Portion control matters for people with diabetes.
- FODMAPs: watermelon is high in fructose and may cause gas or diarrhea in people with IBS.
- Large amounts of potassium may be a concern for people with kidney disease.
- Allergic reaction is rare, and can occur in people with ragweed allergy, causing oral allergy syndrome.
Tip
Choose a melon that is firm and symmetrical, heavy for its size, with a creamy yellow field spot where it rested on the ground. A hollow sound when tapped suggests ripeness.
Safety
Wash the rind before cutting to keep bacteria from the surface off the flesh. Refrigerate cut melon within 2 hours, and eat within 3 to 5 days. Discard if slimy or sour smelling.
Storage
Whole melons keep at room temperature for 7 to 10 days and in the fridge up to 2 weeks. Cut chunks can be frozen for smoothies, though the texture softens.
Water, sugar and lycopene content
Watermelon is about 91 percent water. A cup of diced watermelon (152 grams) has about 46 calories, 9.4 grams of sugar, 0.6 grams of fiber, 11.6 mg of vitamin C and 170 mg of potassium. It is one of the richest fresh sources of lycopene, with about 4.5 mg per cup, an antioxidant also found in tomatoes. Watermelon contains citrulline, an amino acid that the body converts to arginine, and small studies found it may modestly lower blood pressure in adults with prehypertension. The glycemic index is high at about 72 but the glycemic load is low at about 4 per serving because the carbohydrate content is small. Cut watermelon should be refrigerated and eaten within 3 to 5 days, according to food safety guidance, because bacteria can grow on the cut surface.
Based on data from the USDA FoodData Central and the National Watermelon Promotion Board
