Weight Reduction Surgery. This 3D medical animation demonstrates techniques used in bariatric surgery (weight reduction surgery) for obesity, including stomach staple. Bariatric surgery is performed if weight loss efforts through lifestyle changes and medications have been unsuccessful and your body mass index, or BMI, is above 40 or above 35 and you have life-threatenign condition, such as heart disease of diabetes. There are two types of bariatric surgeries; restrictive and malabsorptive. Gastric bypass or Roux-en-Y is both a restrictive and malabsortive procedure, while banding techniques are restrictive procedures and biopacreatic diversion procedure is a malabsorptive procedure.