Grapes, one of the oldest cultivated fruits, are unique because they grow on vines. This bite-size fruit is popular with everyone, especially kids (but be sure to peel and slice them lengthwise for young children to avoid choking). Moreover, they're portable and neat, making them easy low-calorie substitutes for high-fat, calorie-filled snacks and desserts. Bursting with juice, they are a refreshing snack.