• We studied the influence of nutritional support on weight loss and time to regain birth weight (BW) (<1500 g) in infants requiring prolonged assisted ventilation. A total of 134 infants admitted between 1980 and 1982 were reviewed. Birth weight, gestational age, lowest recorded daily weight and percentage of loss, days to recover BW, energy intake, and nutrient source during the BW-recovery period were determined. A decrease in weight loss (13% to 10%) and in mean (±SD) recovery time (20.9 ±7.3 days to 13.8 ±6.4 days) in very-low-birth-weight, critically ill infants was noted. The use of parenteral feeding routes increased, as well as tolerance of initial enteral feedings following parenteral support. We attribute the decreased convalescence period for BW recovery to improved nutrition secondary to the increased use and earlier initiation of parenteral nutrition.