You know, I've watched a fair amount of nature shows, and as far as the "killing animals for our own purposes is wrong!" argument goes, that is so much bullshit that even scientology looks reasonable and well-thought out by comparison. As far as I can tell, nature is ENTIRELY about killing other living things for your own purposes (survival, mostly). Carnivores kill herbivores and other carnivores (territory and dominance struggles, among other things) every day. Herbivores consume plant life in huge amounts until their numbers are culled by the carnivores. And parasitic organisms eat plants and animals alike from the inside out, then spread like wildfire to eat more plants and animals.
Oh sure, you can argue that humans are intelligent enough to suppress their natural instincts and choose not to kill and eat animals, but my question is: why? Despite our automobiles and computers and houses and so on, last I checked we were still part of nature, and we just happen to be omnivorous, which means in turn that a lot of us are going to want to eat meat. As for it being morally wrong: who decided that? You? Fuck you. Hell, the only reason not to kill and eat another person (assuming you have no emotional attachments to them) is that it is against both our social and legal system of laws, and breaking either tends to have very tangible negative results. Well, that and there are far easier ways to get food (you don't usually have to kill someone and cover up all evidence of the murder in order to, say, buy a steak and some fries). And yes, this means I would resort to cannibalism if I had to choose between eating another human being or starving to death. Even if it does mean I'd gain the Aggravate Monster intrinsic.