Sadistic I Am wrote:Oh no. Not at all. But i admit that i have absolutely no justifiable reason to eat meat. But I'm doing it anyway.
It's like a Christian admitting that he has no justifiable reason to believe in Jesus and 'God', but he does anyway (despite all science, historical evidence, logical argument, etc. to the contrary).
Getting somebody to admit that he is behaving completely irrationally is about all you can do. After that, all you can do is wait.
As they say, you can lead a horse to water, but you can't make him drink.
I would suggest, if "Sadistic I Am" is in any way disgusted by the irrational behavior of Christians, he may in the least feel uncomfortable mirroring it. If his loathing for Christianity, and thus discomfort in behaving similarly, ever grows larger than his enjoyment of animal products, he may stop eating them not out of any kind of compassion, but instead out of spite.
It would at least be novel.