摘要:(1) Background: The tolerance of preterm newborns for the high nutritional intakes given by parenteral nutrition (PN) is still debated because of the risk of metabolic complications. Despite enteral nutrition (EN) being the preferred route of nutrition, an exclusive enteral feeding is not always possible, as in preterm newborns, the gut is immature and less tolerant of EN. We aimed to study the impact of a minimal enteral feeding (MEF) on the possible early metabolic complications of PN in a cohort of preterms with gestational age at birth GA ≤ 29 + 6/7 weeks of postmenstrual age. (2) Methods: We divided the study sample in two cohorts: 1) Late-Feeding (cohort 1), newborns who received MEF starting from the 8th day of age, and (2) Early-Feeding (cohort 2), newborns who received MEF, consisting of the administration of at least 4–5 mL/kg/day by the enteral route, in the first 7 days of age. The primary outcome of the study was the rate of at least one metabolic complication, including hyperglycemia, hypertriglyceridemia, or metabolic acidosis. (3) Results: We enrolled 80 newborns (Late-Feeding cohort 51 vs. Early-Feeding cohort 29). The rate of all metabolic complications was statistically higher in the Late-Feeding cohort compared to the Early-Feeding cohort. Binary logistic regression analysis showed that late administration of MEF negatively influenced the rate of all metabolic complications. (4) Conclusions: Early minimal administration of EN is associated with less frequent PN-related metabolic side effects and a higher rate of survival in critically ill newborns.