It sounds like you really need to build all new habits in that first year if you hope to cement the benefits from surgery.
http://www.cbc.ca/news/photos/weight-loss-surgery-benefits-may-diminish-after-5-years-1.3180143
http://www.cbc.ca/news/photos/weight-loss-surgery-benefits-may-diminish-after-5-years-1.3180143