Bariatric surgery (weight loss surgery) is currently the most effective treatment for people suffering from morbid obesity. Although the majority of patients benefit from such an operation, there is still a small but considerable portion of patients who are unable to benefit optimally in terms of weight loss and quality of life. The amount of weight loss after gastric bypass surgery will to a large extent depend on the degree to which the patient succeeds in adopting healthy dietary behaviour. Floor Aarts examines the social and emotional aspects of bariatric surgery and obesity. Particular attention is given to the role of patients’ attachment representations.