Watermelon is a refreshing and low calorie summer snack that only has about 45 calories per cup. By chilling the chopped watermelon in the fridge it can cool you off on a hot summer day. It's an easy snack for kids as well, just hand them a slice and they will go to town. You can also buy seedless watermelon so you don't have to pick through all the hard seeds as you are eating. Another use for watermelon is juice, by crushing it and then straining, you can make homemade watermelon juice. A watermelon is roughly 92% water so it can help to keep you hydrated as well.