Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the essential composition of infant and follow-on formula. This opinion reviews the opinion provided by the Scientific Committee on Food in 2003 on the essential requirements of infant and follow-on formulae in light of more recent evidence and by considering the Panel's opinion of October 2013 on nutrient requirements and dietary intakes of infants and young children in the European Union. The minimum content of a nutrient in formula proposed in this opinion is derived from the intake levels the Panel had considered adequate for the majority of infants in the first six months of life in its previous opinion and an average amount of formula consumed during this period. From a nutritional point of view, the minimum contents of nutrients in infant and follow-on formula proposed by the Panel cover the nutritional needs of virtually all healthy infants born at term and there is no need to exceed these amounts in formulae, as nutrients which are not used or stored have to be excreted and this may put a burden on the infant's metabolism. Therefore, the Panel emphasises that maximum amounts should be interpreted not as target values but rather as upper limits of a range which should not be exceeded.