Obesity has been described as the health crisis of the 21st century. It is a chronic lifelong medical condition, whose pattern often starts in childhood, and is demographically worsening in every developed country. The cost of treating the many medical conditions associated with obesity threatens to overwhelm healthcare resources. Medical treatments produce at most no more than 10% weight loss in the severely obese, with high failure rates. In this article, we review the available evidence regarding long-term reduction in weight, reduced mortality and improvement in most, if not all, obesity-related comorbidities. There is a need for daily multivitamins and extra minerals, especially with gastric bypass, and nutritional deficiencies of vitamins D and B12, Ca, Fe and folate need monitoring and prevention. Currently there is no medical therapy on the near horizon that will match the effect of surgery, which, if done safely, remains the only effective therapy. Bariatric surgery is cost effective, and health providers should embrace the development and rapid expansion of services.