Outside of a few Sharon Marvel had up on her homepage (don’t know if it’s still around or not), I can't really think of any that do have posted examples of their pre-FBBing selves. Of course, that's hardly surprising. Generally speaking, people (especially women) don't like to be reminded of their former state of existence (fat/thin) once they've "improved" their physiques.
I've seen some of them, but unfortunately, I can't find them very easily.