Despite improvements in neonatal care, many preterm babies suffer growth failure during their hospitalization. This appears to persist through early childhood, and possibly into adolescence. The use of enriched formulas improves the early growth of preterm infants, although most if not all of the benefit seems to be lost by 18 months. This growth benefit seems to be restricted to male infants. The improved growth does not improve developmental outcome. Although there are no direct comparisons of 22 kcal/oz post-discharge formulas and 24 kcal/oz preterm formulas, they are probably equally effective. Exactly which component (or components) of enriched formulas is responsible for this growth advantage is not known. Preliminary studies suggest that it may not be protein. Whether this growth benefit leads to decreased morbidity from cardiovascular disease in later life has not been studied. Further research is urgently needed to assess what nutritional factors can improve catch up growth in high-risk infants and whether this improved growth leads to decreased long-term morbidity.