Anne Brenøe (University of Zurich)

Using data from the only large-scale randomized controlled trial promoting prolonged exclusive breastfeeding, we show the intervention significantly and persistently increased weight-for-age, but did not have robust effects on other child health measures. To explain this result, we provide novel evidence of changes in infant feeding patterns. The estimated increase in calories treated infants consumed fully explain the weight gain in early infancy. This suggests breastfeeding has beneficial effects on infant health in contexts where breast milk is a replacement for low-calorie liquids, but effects may not be generalizable to settings where higher-quality alternatives are more common.