Depending on your health, you will need to get clearance from a cardiologist, a nutritionist, a psychologist, your surgeon, your anesthesiologist, blood tests, upper gi, colonoscopy, sleep study, complete poluminary function, heart ultra sound, endoscope, and more if needed. Let them check you out as much as they want. The more they find wrong now, the less chance you will have of having your surgery held up or not being performed at all. Think of this as a 'one-time' head-2-toe check-up! You'll be grateful for it later on when all you have to consentrate on is getting skinny, skinny, skinny! Good luck!