Since the early 1970s, industrial countries have witnessed a resurgence in breastfeeding among newborns and infants to 6 months of age.[1] This upswing in breastfeeding has been accompanied by a deferment in the average age of introduction of other foods (such as cow's milk), resulting in increased use of both breastfeeding and infant formula between the ages of 3–12 months.[2][5]