If you're an hourglass, your butt/thighs should be even with your bustline, my guess is you'll even up there first, till you're about 40-34-40/41 before you start losing in another area.
I was an hourglass until my hips disappeared. And then slowly the bust caught up to the hips. I'm currently 38-29-36 and I haven't lost any off my waist for two months