literally all life on this planet eats each other and gets eaten by each other. carnivores, omnivores, and herbivores alike will eventually process matter that originally existed in the form of some life that is outside their diet.
if you eat a fruit fallen from a tree near a grave yard, you probably ate something that used to be a human
ate beef? you also are what used to be grass
pork? you really dont wanna know with pigs eat
and when you die, you will get eaten by earth worms, which will get eaten by birds, which will get eaten by cats, who get eaten by wolves, who, get killed by bears, hunted by man, and so on and so on infinitely throughout all of time
in fact eating one thing mean you technically ate what used to be billions of creatures backwards through time.
so ethically speaking you cant win