Vegetarianism has been around since ancient India and Greece. I have several friends who are vegetarians and say they love it.
Are there health benefits to it? 
Some think abstaining from animals does lead to health benefits but most vegetarians do it out of respect for life.
What do they call people who do it based on mental issues? Like meat makes you queasy.
Psychology of eating meat
The psychology of eating meat is a complex area of study illustrating the confluence of morality, emotions, cognition, and personality characteristics. Research into the psychological and cultural factors of meat eating suggests correlations with masculinity; support for hierarchical values; and reduced openness to experience. Because meat eating is widely practiced but is sometimes associated with ambivalence, it has been used as a case study in moral psychology to illustrate theories of cognitive dissonance and moral disengagement. Research into the consumer psychology of meat is relevant both
who do not, and it has been applied by animal rights advocates as well as by ethical vegetarians and vegans.
Ethical vegetarians say that the reasons for not hurting or killing animals are similar to the reasons for not hurting or killing humans. They argue that killing an animal, like killing a human, can only be justified in extreme circumstances; consuming a living creature just for its taste, for convenience, or out of habit is not justifiable. Some ethicists have added that humans, unlike other animals, are morally