There is a myth that a physical gastric band is a trouble-free magical solution for obesity. This is not the view of the medical profession and it is important to explain this to clients to get them in the right frame of mind for the work you will do together,

Evidence of the dangers
A study followed up on 82 patients, 12 years after their gastric band surgery. It found:
Half the people in the study no longer had their gastric band. Some had it removed because it was causing problems, some because they no longer wanted it, and others because it didn’t work well enough.
Four in 10 people had serious complications, including damage to the stomach where the band rubbed against the stomach tissue. This happened on average four years after the operation.
Six in 10 people needed a follow-up operation of some type, such as to reposition the band or because the port had slipped out of place.

(Reference: Belgian study reported on the BMJ website