Kramer MS. - 43125 N - Evid Based Med 2012 ; in press.

Exclusive bottle feeding of either formula or breast milk is associated with greater infant weight gain than exclusive breastfeeding, but findings may not reflect a causal effect of bottle feeding

The paper by Li et al addresses a topic that has been much studied and debated over the last several decades: the relationship between type of infant feeding and growth in the first year of life. This study adds a new twist, however: the consideration of bottle feeding, even among infants who receive breast milk via the bottle, rather than formula. Although formula and other nonhuman milk can be provided only by bottle, breast milk can be provided either via the breast or the bottle. Many breastfeeding mothers, particularly those who choose to or are obligated to return to work during breastfeeding, will pump their milk to provide.