If you stop breastfeeding your baby before the 12-month mark, formula should become the drink of choice. Juice, though seemingly healthy, is high in sugars and doesn't contain the iron that formula does. A baby should not have more than four ounces of juice a day, if any. If you wean after baby's first birthday, baby can go straight to whole cow's milk. Children should not drink low-fat or skim until they're at least two. Remember, toddlers need a higher percentage of their diet to be made up of fat.