What reminds us more of a yummy, fun filled food day in the Summer than watermelon? 1 cup of diced watermelon contains approximately calories. It's loaded with vitamin C and vitamin A. Pink watermelon is also a source of the potent carotenoid antioxidant, lycopene. It is high in sugar, 10g per cup, so it's not what you'd eat on a low carb diet, but it's also loaded with water (about 92% worth) so it's good to keep hydrated on a hot summer day. Enjoy!