From here you will be able to know the number of calories they need daily. “For a child ages 4 to 8 years old who gets about 30 minutes per day of moderate exercise, it is recommended to consume 1 to 1.5 cups of fruit, 1.5 cups of vegetables, 2.5 to 5 ounces of 'grain equivalents, 4 ounces of protein equivalents, and 2.5 cups of dairy per day' (MyPlate). It can be difficult for children to meet these daily recommendations, but by replacing certain foods with something better, they can be on the right track in any case..