It's not a regulated profession, and the qualifications of a personal trainer differ depending on the type of the certification(s) and education level. There are certain types of weight training certs that require a physical demonstration of the lifts, e.g. USAW and Crossfit.  And there's some that don't and only require rote memorization, like ACE, NASM, and NSCA (I have a NSCA CPT myself).  And then there's the mack daddy of all certs, the NSCA CSCS, which requires a bachelor degree. Regardless of whether he's fat or not, having a cert doesn't mean shit if the trainer doesn't know what the hell he's doing.  He could be giving his clients terrible instruction on the lifts or put them on a wrong type of regimen which can potentially send them to the hospital.  I've seen irresponsible trainers train the novice clients so rigorously to the point that they developed rhabdomylosis or some other injuries. That said, seeing personal trainers that are both fat and irresponsible is doubly disturbing and abominable.  It's a sight that should insult the sensibilities of fit, responsible personal trainers who genuinely care about their clients well-being and progress.    Anyway, I rambled too much.