Suitable candidates for gastric bypass surgery are generally individuals who: Have a body mass index (BMI) of 35 or higher, indicative of extreme obesity. Have a BMI of 30 to 34,9, along with a serious weight-related health issue like diabetes, high blood pressure, or severe sleep apnea. Candidates should also be ready to commit to lifestyle changes for a healthier life post-surgery. This surgery isn’t suitable for individuals with severe liver disease, blood clotting disorders, severe heart disease, or untreated mental illnesses.