Surgery is generally considered when your body mass index (BMI) is 40 or higher. Surgery may also be an option when your BMI is 35 or higher and you have a life-threatening or disabling problem that is related to your weight, such as type 2 diabetes that is difficult to control with diet, exercise, and medicine.It is important to think of this surgery as a tool to help you lose weight.urgery may also be an option when your BMI is 35 or higher and you have a life-threatening or disabling problem that is related to your weight, such as type 2 diabetes that is difficult to control with diet, exercise, and medicine. It is important to think of this surgery as a tool to help you lose weight.