In this project the investigators want to develop an effective Very Low Calorie Diet (VLCD) treatment prior to bariatric surgery, which is optimized in relation to the size and speed of the weight loss as well as in terms of satisfaction both for the patients as for the health care professionals. Thus the investigators will randomize 500 patients to either VLCD or standard care prior to bariatric surgery. The investigators aim to optimize preoperative and the operative course for patients, who are offered bariatric surgery.
To investigate use of Very Low Calorie Diet preoperatively to bariatric surgery can optimize weight loss prior to surgery and increase the patients' satisfaction.