Complete fasting until resumed bowel function after upper abdominal surgery is not beneficial. Enteral feeding has been claimed to be the preferred way of delivering nutritional support postoperatively. Increasing evidence suggests that letting patients eat ("voluntary oral feeding" or "oral intake at will") from the day after the operation is safe. No prospective randomised trial has been undertaken to compare these two regimens. In this study, we will randomise 444 patients, subject to major upper abdominal surgery, into receiving either continuous enteral feeding by needle catheter jejunostomy until resumed bowel function, or to oral intake at will from postoperative day 1. The main endpoints are the incidence rate of major complications and death, as well as a Quality of Life assessment.