Of course, like anything, if you over-indulge, it will probably be bad for you. But there are some 90 year old men who ate bacon just about every day of their life and smoked two packs a day. And if you ask them, they're pretty glad they enjoyed life by eating meat and doing what they wanted. It takes more resources to support meat-eaters than vegetarians. This may be true, but in the bigger picture, all they are talking about is prolonging the inevitable.
Resources are always finite.
They state that our resources will last 20 times longer if people stopped eating meat. Either way, and they will admit this, they will run out. And, as stated earlier, this utopian dispersement of natural resources they are always talking about is not realistic. People will always be poor and starving, while others will be fat and happy. I'm not saying we shouldn't try to preserve our natural resources.