We have known for years that breast-feeding is associated with less infant weight gain and lower risk of childhood obesity than formula feeding. This new study suggests that it may actually be the act of bottle feeding- regardless of whether the bottle is filled with formula or breast milk- that is associated with increased weight gain during the first year of life.  Compared with infants who were exclusively breast-fed (from the breast only), those who were bottled fed formula gained about 71 grams more per month while those who were given breast milk gained 89 grams more per month.

This association makes sense since breast-fed infants decide when a feeding is over, whereas bottled fed infants are often encouraged to finish a bottle. It seems that there is the most pressure to have infants finish precious breast milk. I can relate to this last theory, I remember the frustration of throwing away pumped milk that I worked so hard to make and keep an ample supply after I went back to work.  I think most of us will agree that breastfeeding, from the breast, is best. Clearly, this is not always possible. Women may not make enough milk, infants are adopted and many women go back to work. This study should not instill any more pressure or guilt than us moms already place on ourselves. What I take from this is that we be more mindful about honoring our babies natural hunger cues and stop a bottle feeding when they seem like they have had enough- even if that means throwing out valuable pumped breast milk or pricey formula.