Hi there, please let me know his height. BMI (Body mass index) is the index that will help in deciding the procedure for him. There are multiple procedures that com under the umbrella of Bariatric surgery. It should always be individualised person to person. Sleeve Gastrectomy and Gastric Bypass are the two common procedures. Bariatric surgery is indicated if a person has BMI>37.5 without any morbidity OR BMI>32.5 if there is any morbidity resultant from obesity besides weight (Diabetes, Blood pressure, Sleep Apnoea/Snoring, Arthritis). After 1- 1 1/2yrs of Bariatric surgery approx 80% of his excess weight disappear alongwith improvement in all the morbidities. But as I said, procedure is to be individualised, so you should meet one trained Bariatric surgeon for the same.