Check out the number of top athletes who are vegetarian or vegan. Go to a typical Spartan race in your state and you'll find a ton of top performers who don't eat meat. If you are in the US, there are enough healthy alternatives even outside the two coasts.

Also, this choice doesn't have to be binary. One could eat less meat - either smaller quantities or fewer meals with meat each week. The end goal is simple - reduce the number of animals who have to be raised and killed for meat each year. If one agrees on that (and one might not), then even reducing your intake by 10% helps a lot.