I have long been a vegetarian and in some Jewish contexts I have been asked how this is possible. Well, at my community it is certainly very hard because food basically equals lots of meat for most of the people. So as a vegetarian I sit there and eat the side dishes or nibble some bread with Humus.
But the real question these people want to ask is, what does the Torah say? Does G-d allow us to be vegetarians? Does G-d maybe even want us to be vegetarians? I cannot give an exhaustive treatment to the question, so I list only some points that I think are important:
- Mankind was originally created to be vegetarian: "And God said: ‘Behold, I have given you every herb yielding seed, which is upon the face of all the earth, and every tree, in which is the fruit of a tree yielding seed–to you it shall be for food;" (Genesis 1:29).
- Some people (e.g., Rav Kook) say the permission to eat meat given after the flood was a temporary concession (A Vegetarian View of the Torah).
- Meat consumption needs more thought and is restricted by design as kashrut makes it more difficult to eat meat, pretty much all complicated rules have to do with meat (kosher species, slaughtering, milk-meat combinations), kashrut is very simple if you don’t eat meat.
- Meat does not have a special bracha, it has the "catch-all" sheHaKol. Unlike wine or bread it is not a necessity that needs to be singled out.
- Jewish law advocates compassion and good treatment of animals (Which Torah laws involve compassion for animals?), you may not cause harm to an animal unnecessarily (tza’ar ba’alei chayim). This is in sharp contrast to the horrible treatment of animals in commercial meat production (How are farmed animals treated today?).
While this may not amount to a commandment to be vegetarian, I think it does give enough grounds to allow being a vegetarian.