Combined with over compensating for not being wanted any other way...yes. This is the right answer.   These "fatties" finally have someone pay a little bit of attention to them and they don't know how to handle it.  They sure don't want to lose it, so they , in turn do ANYTHING to keep that attention coming back.  Multiply that by a few other factors, like parents that either try and control their every move or ignore them altogether...well  that's a recipe for a stripper/prostitute/skank...all the same thing, with slight variances in job expectations.