Gastric Sleeve surgery, also known as Roux-en-Y gastric bypass, is a surgical procedure designed to help individuals achieve a significant weight loss. Gastric bypass surgery is typically recommended for individuals with a body mass index (BMI) of 40 or higher  or those with a BMI of 35-39 with obesity - related health conditions. Along with substantial weight loss, gastric bypass surgery can result in improvement or resolution  of obesity related health issues such as diabetes, high blood pressure, and sleep apnea. Patients typically lose 55-70% of body weight within 12-18 months.