The present invention is directed to a computer-based weight loss system for supporting bariatric treatment of obesity that is accessible to both the patient and the medical practitioner. The system has a central server maintaining a library of information related to the treatment of obesity and a patient interface and a medical practitioner interface linked to the central server for uploading and downloading of information. The patient interface also provides access to information selected from the group consisting of bariatric care pathway, behavioral modification planning, fitness, preoperative diet, postoperative diet, monitoring of a gastric band, monitoring of a patient's weight, monitoring caloric intake and nutritional information. The uploaded information is processed by the central server and then made available to the medical practitioner and the patient.