To be eligible for bariatric surgery, you must be between the ages of 16 and 70 (with a few exceptions) and morbidly obese (weigh at least 100 pounds above your ideal body weight and have a BMI of 40).
Gastric bypass, sleeve gastrectomy, and the adjustable gastric band were the three types of surgery (also known as a gastric band). The study found that gastric bypass surgery boasted the most weight loss, both in the short and long term.
Some patients must lose 10 percent of their weight before having weight loss surgery. For other patients, losing just 15 to 20 pounds just before surgery is enough to reduce the risk of complications.