Current information and concepts regarding unique features and practical aspects of metabolism and the nutritional management of critically ill, very low birthweight neonates are reviewed in this article. The use of ''gut priming'' (early hypocaloric minimal enteral feeding) and parenteral nutrition and their application to the treatment of specific disease states is discussed. The concepts of critical oxygen delivery and multiorgan failure and their impact on nutritional management in adult; show striking similarities to metabolic observations of progressively deteriorating, sick neonates.