OSuzanna,
I think most of us go from the weight we were when we made the decision to be banded or from before we started the pre-op diet.
I was 285 when I made the decision, 280 before starting pre-op, 268 when I was banded, now 240. Total loss 45 lbs.
I think if you start the day before pre-op, you will get a fair number of what you've lost since the banding process began.