A sort of challenge that is leveled often at vegans is
"If you were alone on a deserted island with a pig, would you eat the pig or starve to death?"
I found a pretty good answer
"Hmm. If you were not alone, living on a planet with 7 billion people, had access to unlimited fresh fruits, vegetables, nuts, beans, and other healthy foods, and knew animals suffer and die horrible deaths so you could eat them when you don't need to eat them to survive, would you continue to eat them? The difference between our questions is that your scenario will never happen and mine is the choice you face right now. Which do you believe is worth answering?