Disclosed is a method of increasing lean body mass and reducing fat body mass in infants, said method comprising administration to an infant, term or preterm, a nutritional formula comprising a source of DHA and ARA. It has been found that the administration of DHA and ARA, or a source thereof, in infants can increase lean body mass and reduce fat body mass, when compared to an unsupplemented control formula, without impacting the total overall growth of the infant. This method is especially useful in preterm infants.
