"Unfortunately that has consequences: they get in the habit of giving the bottle or giving food to manage children's behavior," he said. "It sets up a dynamic of the kids getting food for reasons that have much less to do with hunger or appetite than behavior issues." That, in turn, can lead to children having an unhealthy relationship with food, putting them at risk of the overeating that can drive obesity.
When parents come to him with children who continue to drink from a bottle beyond the age of 12 months, he asks, "'Can the child drink appropriately from a cup? If they can, there's no more need for the bottle. Certainly by age 2, it's time to stop, assuming the child has appropriate cup-drinking skills."
Prolonged use of a bottle can decay teeth, he said, particularly if parents are filling that bottle with juice or something "fruit-flavored and often sugary." The bottle also can become a meal substitute, "so that the kids are not eating. It can displace a balanced diet."
Ayoob said he has no problem with a child consuming two glasses of milk a day, because it's "a primary source of protein and a whole bunch of other nutrients." But after that, he said, "Let's get kids used to drinking water. Let's not feed anything excessively."
Bogen said that another way to keep kids from overconsuming calories as they're being weaned from bottles is to only allow them to drink from a bottle during meal time "while the toddler is sitting at the table/high chair" and to make sure they don't walk around with a bottle or sippy cup in hand. Bogen also said a sippy cup should not be "filled with juice or milk to have all day." Ideally, she said, toddlers "should be offered water between meals."
The study was funded by the U.S. Department of Agriculture's Food Assistance and Nutrition Research Program.