How much fat is in watermelon?

According to health and nutrition writer Bridget Coila for SFGate, a cup of watermelon contains less than a gram of fat. One cup of watermelon also contains 11 grams of carbohydrates and only 46 calories.

Coila also explains that watermelon has a very low glycemic load of four, a reading that suggests that watermelon does not raise blood sugar levels or influence weight gain. Watermelon contains a substance known as citrulline, which breaks down during metabolism into the essential amino acid arginine. Some research indicates that increasing arginine levels in the blood may reduce the rate that the body stores fat.