Bariatric surgery is a category of weight-reduction surgical procedures recommended for individuals for whom repeated attempts to lose weight have been unsuccessful, or for those whose obesity poses a direct risk of death. It involves altering the gastrointestinal system to either reduce the volume of food that can be consumed or limit the body's ability to absorb digested food. Studies indicate it is more effective than non-surgical treatments in the short term (two years post-procedure), though long-term studies are still needed.