living on only protein will cause rabbit starvation.
however, ketosis was not in the playbook of christopher, and seems like you as well.
oversimplification from lead-damaged low iq, or willful misdirection, i guess it doesn't matter.
the carnies are living on fat.
if the carnies were destroying themselves (through extreme catabolism) as you said then they wouldn't last more than a few months and they would be rail thin. reality shows this not to be the case.
are you able to look at reality? no? i didn't think so.