 We are proposing to evaluate the benefit of preoperative nutritional support with Impact Advanced Recovery in the most vulnerable group of elective gastrointestinal surgery patients who may experience a complication, esophagus and pancreas resections, and hypothesize that oral supplementation with 3 servings 0.75 L Impact Advanced Recovery will reduce postoperative stay by 10-20 and reduce the incidence of major complications by 25. 