What insurance do you have?
I just started the process and worried about this myself. I applied back in '04 when I was 19 and was denied when I was at a weight of 425lb. After that I tried to lose what I could by myself and lost 200lbs in about 18 months but have regained pretty much all of it since then. Have tried losing again but it's just a yo-yo with my weight.
Have my first consultation this Friday so we'll see how it goes.