For sarcasm or unintrested people, not nice folks truly wanting to know more. Most of the time this will stop an uncomfortable exchange. Some of these I've heard from others, so I can't take credit for all of them.
"You eat rabbit food?"
"You eat vulture food?"
"Where do you get your protein"
"Where does a cow get its protein?"
"Is that all you are going to eat?"
"Are you going to eat all that?"
"Are you going to eat all that (tons of lettuce, fruit)?"
"You are just going to eat that (sandwich, hot dog, etc)"
"Where do you get your (nutrients)?"
"Everything I eat - where do you get yours?"
"What you are eating is nasty"
"And the inside of a cow isn't?"
"Shouldn't you be eating for two, you're pregnant!"
"I'm not carrying a 150 lb. human in here"
Would love to hear others...