 This study aimed to investigate the effect of enteral feedings macronutrient composition on inflammatory mediators, oxidative stress and outcomes in Intensive Care Unit ICU patients with acute respiratory failure. In this double-blind randomized control trial, 42 patients of both sexes and diagnosed with acute respiratory failure in ICU that receive enteral feeding, will be randomly assigned to three groups of 14 each. First Intervention group; high-protein low-carbohydrate diet with high olive oil, the second intervention group; high-protein low-carbohydrate diet with high sunflower oil and control; high-protein kitchen formula. Intravenous levels of uric acid, high sensitive C-Reactive Protein hs-CRP, Interleukin 6 IL-6 and Total Antioxidant Capacity TAC measured at days 0 and 10. As well as, organ failure, duration of ventilation, length of ICU stay and mortality rates will be evaluated. 