"I don't like the taste of meat." That's fair. Why on Earth would you force yourself to eat something you don't like the taste of? There's no need to be a masochist.
"I find the whole concept of slaughtering animals disgusting." This is also fair. For some reason, the idea of a cow being disembowelled as it hangs from a hook by its back hooves doesn't bother me at all, bu the idea of a veal calf sitting in a small pen surrounded by its own diarrhea makes me gag. Possibly the only way to turn me into a vegetarian would be to convince me that an integral part of raising all edible livestock is forcing it to sit in its own shit. (I say possibly because I could never see myself giving up barbecued pork ribs.)
"I feel healthier when I don't eat meat." Rock on! I'm all for feeling healthy. I'm glad that cutting meat out of your diet works for you. I like it too much to cut it out of mine, although I have decreased the amount of red meat that I eat.
When people start quoting statistics at me about the number of people who could be fed if we didn't eat livestock or how raising livestock is stripping the Earth of its natural resources, they automatically earn points towards the "sanctimonious prat" tag. This happens because everyone who has done this to me has at some point or another baldly stated that the fact that I eat meat makes me a bad person. I have no time for people who think that way.
Link stolen from Tom, who is most certainly not a sanctimonious prat.