I was require to also do the six months of dieting but my doctor and staff explained to me that it is also important to do the pre op diet because of after the surgery. It took me 2 months to give up coca cola. Then I had to change my eating habits trying to eat and not drink at the same time. They told me that people who try this before surgery are more prepared after surgery. If you are a self pay the 6 months does not apply but there are bad habits to break.