What exactly is the youngest they can preform bariatric (weight loss) surgery on?

Teenagers: Bariatric surgery is being offered to teenagers and ahs been performed succesfully with good results. However i recomend you find a bariatric surgeon who is willing and comfortable working with this population, and only consider it in a patient who is willing to comply with all the dietary reccomendations as well.

Depends: The most accepted answer is when the child has stopped growing. You want the growth plates to be fully mature before undergoing bariatric surgery.