What are the risks of excess alcohol before weight loss surgery?

Excess alcohol intake in somebody who is contemplating weight loss surgery really needs to be looked at because alcohol is a source of empty calories and for some patients who may otherwise have of healthy diets, they may have put on weight because of the quantity of alcohol that's being consumed. So it is important to address this before any weight loss surgery because if one continues drinking high amounts of alcohol after surgery, this will actually reduce the benefits of the surgery in terms of weight loss.