definitely no corn, beans or peppers before Columbus

Barley was a sign of degradation and poverty, but the dietary regimens of gladiators were often quite expensive. Pescatarianism was highly regarded by the Romans for both health and cultural reasons.

Not all gladiator scenery slaves. It was a profession like a boxer.

Interesting how when 'barely men' revolted they managed to slaughter 'organized armies of real men' 10x their number.

Makes one curious of slaves and gladiators were allowed garum. It seems ubiquitous but how much was spent on those about to die?

It depends on the owner and the slave in question but otherwise sure, there were obviously plenty of slaves who never got the fame or wins to get their little treats.