: In a double blind clinical trial, 80 critically ill adult patients were randomized to hyperproteic hypocaloric or to isocaloric enteral nutrition; all patients completed follow-up of at least 4 days. Prescribed caloric intake was: Hyperproteic hypocaloric enteral nutrition (15 kcal/kg with 1.7 g/kg of protein) or isocaloric enteral nutrition (25 kcal/kg with 20% of the calories as protein). The main outcome was the differences in delta SOFA at 48 h. Secondary outcomes were intensive care unit (ICU) length of stay, days on ventilator, hyperglycemic events, and insulin requirements.