- Overfeeding of critically ill patients is associated with a higher incidence of infections and an increased length of ventilation. However, trophic nutrition or permissive underfeeding appears to have no negative effect on the patient and may even provide a survival benefit.- Initiation of enteral nutrition within 24-48 hours after Intensive Care Unit (ICU) admission may reduce the number of complications and increase the chance of survival.- Total parenteral nutrition is associated with a higher risk of infections than enteral nutrition. This seems to be related to the higher calorie intake with parenteral nutrition rather than the route of administration.- In previously well-nourished patients, in whom enteral nutrition is only partially successful, it is safe to wait for up to 8 days before initiating supplemental parenteral nutrition.- In critically ill children, it is also safe to start supplemental parenteral nutrition at a late (on the 8th day after admission) rather than an early stage (within 24 hours of admission). Late supplemental parenteral nutrition may even result in fewer infectious complications and shorter hospitalisation.