Id be interested to hear from Christian’s though why they link vegetarianism with Christianity- how does this link into man’s dominion over all other creatures.
OK full disclosure, although I'm a Christian I am still getting to grips with theology! So the reason behind vegetarianism seems to be because that's how God set things up in the Garden of Eden (Genesis 1:29-30)
Then God said, “I give you every seed-bearing plant on the face of the whole earth and every tree that has fruit with seed in it. They will be yours for food. And to all the beasts of the earth and all the birds in the sky and all the creatures that move along the ground—everything that has the breath of life in it—I give every green plant for food.” And it was so.
So before the Fall, yes we were vegetarian (and as far as I can make out, will be again in Heaven after the return of Jesus).
Man has 'dominion' over creatures means he is in control of what happens to them, it doesn't mean we get to eat them necessarily, although we do.
It's interesting that in Matthew 14:19 we see the miracle of the loaves and fishes where Jesus feeds 5000 people from 2 fish and a 5 loaves. So clearly not veggies there. Perhaps that's why Christians were pescatarian. I have to look into that, but apparently pescatarianism was widespread in the early church.
As for me, I don't eat red meat anyway. Would I give up eating chicken and fish? No. Because my health is already poor enough, giving those up would make things worse.