Patients admitted to the intensive care unit (ICU) with acute respiratory distress syndrome (ARDS) suffer from profound weight loss while hospitalized and have nutritional related residual effects up to a year post-discharge. Malnutrition is associated with both poor outcomes, however, if optimizing nutritional care can reverse this and improve outcomes in this population is not known. The nutritional care provided to ARDS patients typically consists of enteral nutrition (EN) while mechanically ventilated followed by a general diet when weaned from the ventilator. EN is a medical intervention that has risks and cost yet no studies have demonstrated its efficacy in this population. Further, no studies have evaluated any aspect of nutritional care provided once EN is discontinued. We propose a prospective randomized clinical trail to evaluate the impact of intensive medical nutrition therapy (IMNT) in malnourished respiratory failure patients admitted to the ICU on short and long-term outcomes. Participant's (N = 200) will be randomized to receive either standard care (SC e.g. ad lib feeding of standard food) or IMNT provided as EN started within the first 48 hours of ICU admission and continued until 75% of estimated energy needs are achieved via a individualized, intensive diet therapy tailored to maximize oral intake until hospital discharge. Primary outcomes evaluated while hospitalized include infections, days on mechanical ventilation, in the ICU and hospital and changes in various immune parameters. At discharge, 3- and 6-months post discharge participants will be assessed for changes in fat free mass (measured by dual energy x-ray absorptiometry), weight, muscular weakness (measured as hand grip strength), fatigue (measured as distanced traveled in 6-minute walk assessed at discharge and changes in various immune parameters. The proposed PRCT is designed to assess if malnutrition independently causes morbidity, and if IMNT can reverse malnutrition, improve immune function and other clinical outcomes. It employs a comprehensive nutrition program from ICU admission to hospital discharge, links the changes observed mechanistically to immune function and has the potential to expand our understanding of methods that improve both short-term (within the ICU and while hospitalized) and long-term post-ICU morbidities. It will provide the vital translational information necessary for clinicians to deliver EBM for the nutritional care of these patients from bench-to-bedside practice. As ICU survival rates improve and resources become scarcer studies addressing these issues are highly relevant. PUBLIC HEALTH RELEVANCE: Patients admitted to the intensive care unit (ICU) with respiratory failure suffer from profound weight loss while hospitalized and have nutritional related residual effects up to a year post-discharge. The proposed clinical trial will examine the impact of an intensive medical nutrition therapy intervention designed to curtail these nutritional declines on various clinical as well as immunological outcomes while hospitalized and 3- and 6- months after hospital discharge. As ICU survival rates improve and resources become scarcer studies which provide information to guide practices that can ameliorate the short and long term consequences of the ICU stay are badly needed and highly relevant.