To be considered for weight-loss surgery, you must satisfy the following criteria: Have a BMI of 40 or above, or a BMI between 35 and 40 combined with an obesity-related disorder such as heart disease, diabetes, high blood pressure, or severe sleep apnea. The surgeon may also ask you to try other treatments first. These could include changing your diet by eating less food and more nutritious items or using a gastric balloon to reduce how much you eat.