"When a child is full and pushes away, stop," BYU sociology professor Renata Forste said in a statement. "Don't encourage them to finish the whole bottle."
The analysis of data from more than 8,000 families found other feeding habits that can contribute to children becoming obese by 24 months:
• Putting babies to bed with a bottle. It seems to promote a need to eat before sleep, instead of allowing a child to self-regulate, and increased the risk of childhood obesity by 36 percent.
• Encouraging a baby to keep eating after he or she pushes away.
• Feeding a child solid foods before 4 months, a habit that drove up the risk of obesity by 40 percent, according to the study.
"The health community is looking to the origins of the obesity epidemic, and more and more, scholars are looking toward early childhood," said BYU sociology professor Ben Gibbs, the lead author on the study. "I don't think this is some nascent, unimportant time period. It's very critical."
There is also a socioeconomic angle. Lower-income families with less education seem to formula-feed more often and they are also hardest hit by childhood obesity, said Sally Findley, a public health professor at Columbia University.
"Bottle feeding somehow changes the feeding dynamic," she said in a BYU news release, "and those who bottle feed, alone or mixed with some breast-feeding, are more likely to add cereal or sweeteners to their infant's bottle at an early age, even before feeding cereal with a spoon."