How many calories in fruit. We are often asked how many calories are in fruit. Of course the amount of calories between different fruit varies, but when compared to vegetables in general, fruit contains more calories because of the fructose (fruit sugar) that they contain.Fruit is a good source of energy and a high fiber food.e are often asked how many calories are in fruit. Of course the amount of calories between different fruit varies, but when compared to vegetables in general, fruit contains more calories because of the fructose (fruit sugar) that they contain.