 Bariatric surgery is a hormonal surgery in these procedures, for which the alteration in gut hormones develops as a result of the procedure's restriction and malabsorption.Long-term studies show the procedures cause significant long-term loss of weight, recovery from diabetes, improvement in cardiovascular risk factors, and a mortality reduction from 40% to 23%.The U.S. National Institutes of Health recommends bariatric surgery for obese people with a body mass index (BMI) of at least 40, and for people with BMI of at least 35 and serious coexisting medical conditions such as diabetes.