The American Academy of Pediatrics recommends that parents not feed fat-modified foods to children 1-2 years of age (Pediatric Nutrition Handbook, fourth edition, AAP, 1998), including 2%, 1% or fat-free milk. Children this age need foods with a high caloric density for growth.
After age of 2 years, the 1995 Dietary Guidelines recommend that children gradually adopt a diet that by about five years of age, contains no more than 30 percent of calories from fat. So between the years of 2 and 5 it is up to the child's parent and pediatrician what type of milk is best for that particular child, depending upon how well the child is eating and growing and which type of milk they prefer, rather than risk having them drink less or none at all.
According to the latest recommendations from the National Academy of Sciences, children ages 1-3 need 500 mg of calcium daily, or the equivalent of 3 small servings of milk (6 ounces of milk or yogurt or 1 ounce of cheese.) children 4-8 need 800 mg of calcium, or the equivalent of 3 servings of milk (8 ounces of milk or yogurt or 1 ½ ounces of cheese.)