My wife had a stomach reduction procedure a year ago. Before that she had to follow a strict psicological therapy for a year to be approved for the procedure, this is not required but that's how her doctor works.
She had several options, and the advice from her doctor was to choose any of the couple of reducing stomach interventions. All the other options which include putting some kind of contraption into the stomach fail in a big percentage of the patients. This happens because patients learn to control the comtraptions, air balloons, etc. and end tricking them to eat more.