Breastmilk and formula are the only liquids they need.
It's a question that a lot of new parents ask themselves, especially when they might be receiving outdated advice from well-meaning but incorrectly informed friends and family: Do babies really need to drink water?
The answer is no. According to the World Health Organization (WHO) , babies under 6 months old do not need water.
"Breast milk is more than 80% water, especially the first milk that comes with each feed. Therefore, whenever the mother feels her baby is thirsty she can breastfeed him or her," WHO states on its website.
Formula-fed babies, too, don't need water. They can get all the hydration and nutrition they need from formula. As pediatrician Catherine Pound told Today's Parent, giving a baby under 6 months water in a bottle "interferes with feeding and can lead to poor weight gain."
Registered dietitian Katie Zeratsky of the Mayo Clinic agrees with Pound. Zeratsky told Buzzfeed: "We don't want babies to fill up on water because it would make them miss out on key nutrients like protein, vitamins, minerals, carbohydrates and fat intake. Human milk and formula are meant to be the mainstay of their nutritional intake because it is such an important time for a baby's growth. Babies are growing so rapidly that their energy needs compared to ours, pound for pound, are much higher."
According to the American Academy of Pediatrics, parents should only feed babies breastmilk or formula in their bottles (no water, no juice, no infant cereal) unless they are directly advised to serve another liquid by a physician.
Even on hot days, parents don't need to feed babies water. Bottle fed babies may require more frequent formula feeds during hot weather in order to stay hydrated and breastfeeding babies may want to nurse more than usual if it's hot out, but water should not be offered until they are older.
If you have any questions about your baby's hydration and nutrition, don't hesitate to ask your pediatrician or health care provider.