When children become critically ill and need invasive mechanical ventilation, making sure that they get the right amount of nutritional support is crucial, not only for the physiologic needs of delivering appropriate amounts of calories and protein, but also for the needs of the family, where feeding constitutes such an important part of childcare. Deliver too much enteral nutrition, and you may run the risk of complications, including aspiration or vomiting or gut diseases, such as necrotizing enterocolitis. Deliver too little enteral nutrition, and there may be inadequate calories contributing to delayed recovery.