The finding comes from a study by Rutgers University researchers of 96 low-income black and Hispanic mothers who formula-fed their babies. The mothers recorded information about their babies' feedings, and researchers visited the mothers when the babies were 3, 6 and 12 months old to observe feedings and to weigh the babies.

The study looked at a number of possible variables linked to infant weight gain and found that the number of feedings a day at 6 months approached significance in predicting weight gain from 6 to 12 months. It also found that mothers who were less sensitive to signals that their babies were full had infants who gained more weight.

"More frequent feedings, particularly with formula, are an easy culprit on which to assign blame," the researchers wrote. But a mother's "unwillingness to slow the pace of feeding or terminate the feeding when the infant shows satiation cues may be overriding the infant's ability to self-regulate its intake," they said.

However, they acknowledged that changing a mother's feeding habits could be extremely challenging.

"Feeding an infant is a primal behavior, and to suggest to a new mother that she is feeding her infant too often, too much or, worse yet, is not very good at reading her infant's signals would require an extremely skilled nurse or social worker," they said. "Giving counsel after watching a mother feed her infant might be seen as threatening or, at the very least, meddling, and just pointing it out could be construed as an accusation of 'poor mothering.'"

The study is in the May/June issue of the Journal of Nutrition Education and Behavior.

More information

The U.S. Food and Drug Administration has more about feeding infants.