I think this thing comes down to whether or not you believe in God.
If you do, then killing and eating animal is not an issue because he made animals for us for that purpose. If you are an atheist, then I think you're more incline to have an issue with killing animals because you would view all living things on a level plane.
If you do, then killing and eating animal is not an issue because he made animals for us for that purpose. If you are an atheist, then I think you're more incline to have an issue with killing animals because you would view all living things on a level plane.