More than a third of patients who had bariatric surgery got back to a BMI of 30 or less after one year. Some patients respond better than others, and some operations are more effective than others.
Having a BMI of less than 40 made it more likely for the person to reach their goal weight. Obviously, they had less to lose. Only one out of ten patients who had a BMI of 50 or over got down to a BMI of 30, which corresponds to the limit between being considered overweight and being considered obese.
Sleeve gastrectomy, gastric bypass or duodenal switch operations were the most effective. Adjustable gastric bands were less effective.
BMJ 9 Dec 2017 from JAMA Surg 2017