Watermelon's water content is up to 93% or more, and its sugar content is about 5%. What makes watermelon taste sweet is "fructose", which accounts for more than 50% of the total sugar content, and the glycemic index (GI) of fructose is very low.

Watermelon as a meal. Watermelon is more than 94 percent water, but the sugar content itself is also very high. Normal sweetness watermelon contains 5% sugar, so watermelon is very high in calories, and watermelon has 250 kcal/kg. That is to say if you eat a very large watermelon every day, about 8 to 10 pounds, that is the intake of 1000 kcal to 1250 kcal calories, while a normal bowl of rice calories is about 200 kcal. That is to say that eating a watermelon is equivalent to eating five or six bowls of rice. So eating watermelon as a meal is not to be.