I keep telling myself food is not a problem for me, that I'm overweight because I have a back injury but in reality my portion sizes at dinner are too big, I do try to eat a healthy breakfast & lunch but a chocolate bar or crisps will somehow find a way into my hands, I think maybe a good way to prepare yourself is to decide to cut out a certain food every week or every couple of days if ur near to having op, write them down and tick off what you are going to stop that day/week
I'm not sure if it helps but try to keep busy aswell so you don't go reaching for food or thinking about it, put a photo of yourself on the fridge and tell yourself you don't want the food, have a drink of water or juice to fill you up instead, I hope my advice helps even a little, 2014 is our year, food does not control us
Good luck xx