Infants over 6 months of age can be introduced to other foods, and formula remains the main source of nutrition for infants and children. The recommended amount of milk is 800ml/day up to one year of age. How to feed preterm infants? 1）Birth weight <1800g, choose preterm formula or fortified breast milk. 2）Birth weight >1800g, growth parameters reach the 25th percentile of the equivalent gestational age, can be converted to standard formula. 3）Corrected age 4-6 months, growth parameters reach the 25th percentile of the equivalent gestational age, can be converted to standard formula or exclusive breast milk. Therapeutic formula: 1) Milk allergy: human milk is the best hypoallergenic food, extend breastfeeding to 12-18 months. 2) Formula needs to be free amino acid formula or deeply hydrolyzed protein formula. Partially hydrolyzed protein formula, soy formula, and goat milk should not be used to treat cow’s milk allergy. 3) Lactose intolerance: infants with congenital lactose intolerance should be on long-term lactose-free formula. Infants with diarrhea >3d causing secondary lactose intolerance can be used until 2-4 weeks after healing. How much water is appropriate for infants to feed? An infant’s intake of water is generally adequate as indicated by 6-7 urinations per day. Infants can obtain adequate amounts of water from breast milk and other foods. To reduce gastrointestinal burden and contamination, avoid giving excessive additional water or juice to infants. Young children with food close to that of adults can drink water appropriately, especially in summer. Water or juice should not be consumed one hour before a meal.