Cerebrospinal Fluid Biomarkers in Bariatric Surgery

"This surgery is often called gastric bypass. It is a weight-loss surgery that involves creating a small stomach pouch and bypassing part of the small intestine.~If you decide with your doctor to have gastric bypass, you can be enrolled on this arm of the study. A surgery date should be pending before the investigators screen you for the study. The study does not cover the cost of the Roux-en-Y gastric bypass."

"Sleeve gastrectomy, is a weight-loss surgery that involves removing about 80% of the stomach.~If you decide with your doctor to have sleeve gastrectomy, you can be enrolled on this arm of the study. A surgery date should be pending before the investigators screen you for the study. The study does not cover the cost of the sleeve gastrectomy."

Weight loss with calorie restricted liquid diet. Participants will be placed on a 800 kcal/day diet for meal replacement (Optifast) provided by the investigator for 12 weeks. Participants will be monitored weekly by the study dietician and medical staff.