No, but I order off vegetarian menus quite a lot.
Being a vegetarian can be very bad for you as you can't get all your required nutrients just from plants.
Remember kids, there's a reason we are omnivores.
As a matter of fact you can. I happen to know a couple of vegetarians and they're among the healthiest people I know. This is probably because they've all carefully planned their diets so that they get all the nutrients they need. The big thing is fruit dependent diets tend to be low on protein and you have to eat a bunch of food fortified with B12.
But I would argue that the health benefit is primarily because they planned their diet, not necessarily from being a vegetarian. My view has been that being a vegetarian means you've eliminated meat from your diet through careful planning and monitoring of your nutrition. Someone who just woke up one day and decided they were going to only eat vegetables for the rest of their life is just handicapped and probably going to die early. They might technically be a vegetarian but they totally missed the whole point of it.