A surgical or laparoscopic method of treating obesity of a patient using a device adapted to stretch a portion of the stomach wall of said patient. The method comprising the steps of: cutting a hole in the abdominal wall of said patient, dissecting an area around the stomach, placing said device in contact with the stomach, and fixating, direct or indirect, through invagination of the stomach wall, said device to the stomach wall such that said device can stretch a portion of said stomach wall.