Juice and Water
But limit juice as it can result in gas or diarrhea. How to limit intake: give with food to slow down rate of absorption, dilute 1:1 with water. Give water with meals, as giving milk/formula/juice can curb appetite for solid foods.
1-6 y/o: 4-6 oz per day
7-18 y/o: 8-12 oz per day or 2 servings per day
AAP Caring for baby and child: Birth to age 5, revised edition.
Study upholds danger of drinking too much sweetened beverage
Assessment of the daily dietary intake of 20 children 6-13 years of age showed that children who drink a large quantity of sweetened drinks consumed less milk than other children and, therefore, ingested less daily protein, calcium, magnesium, phosphorus, and vitamin A. In addition, children who drank more than 12 oz per day of sweetened beverage consumed more daily calories - they ate the same amount of solid food as other children - and gained more weight.
(Mrjdenovic G, et al. J Pediatr 2003; 142:604)