Yes, we need. Known several ex-vegetarians that had to eat meat again cause they were getting sick. Vegetarianism isn't for everyone.

If you mean cheating the universe and biology is by not having jobs or things that demand fisical strenght. Most of them have a cedentary lifestyle wich it doesnt demand alot of creatine or proteine to upkeep the muscles.

Ok well let me ask you this then, if all of humanity stopped eating animals, what do you suppose would happen? All the animals would just live happily ever after? No. Over population, increased diseases, etc. I suppose you're right, some of us could go completely vegetarian and live off of only vegetables if we get enough sources of protein from other vegetarian substances. But that's not going to make animals any happier. The animals we eat were bred to be slaughtered. Some of them may have been raised cruelly, which is truly unfortunate, but most of them live decent lives until the point they are served on a plate. And also, can I ask a second question? Your comment seems to promote the idea of vegetarians as a kinder lifestyle. But what gives the plants less right to live than animals? Plants are living creatures too.

Some can live perfectly fine without it, others don't. Just like some vegans had to go back to being vegetarian due to heath reasons, while others thrive. The people who are so gung ho about everyone becoming vegetarian should maybe look for answers about that and what to do with the animals in question instead of trying to shame and/or bully others to their views.

Why? It's spelled supplements.