The greater weight gain velocity in the infants fed an increased enteral energy intake may be partially explained by the fact that infants with BPD require more energy to support the increased work load involved in breathing and maintaining metabolic rate [5, 9]. We increased energy intake as it has been found that infants with BPD need more calories than age-matched healthy controls [11]. However, it must be noted that, although mean actual energy intake ranged from 126 to 131 kcal/kg/day, BPD-related feeding difficulties prevented higher energy intakes that may have promoted growth in the most severely affected infants. As suggested by others [11], in order to meet further caloric demands, we used fat rather than carbohydrates because this allows energy supplementation using small volumes and produces low amounts of carbon dioxide. Furthermore, fat was increased rather than protein intake in order to avoid protein oxidation and promote tissue accretion