You would be a lot better off starting now as it wont be such a shock to you when you do your pre op diet.
I followed Weight Watchers while I was waiting for my 1st date.
I saw the dietition and choose the Slimfast diet but instead of having 5 bottles per day I had 2, one for breakfast and one for lunch, then a good healthy dinner.
If you are really serious about losing weight then you will have to cut back at some time, so why not make it easier for youselves and start now.
I started ww in Sept 2009, then my version of slimfast at beginning of Mar 2010, I started the 5per day slimfast on 15 Mar and had my op on 27th
I was a little over 33st before I started and was 29st when I went on the table. I am now 26 1/2 st and still going down. It is not easy but well worth it
I hope this is use full to you