processed meats are horrible on the body. this means bacon, fried chicken, sausage, cold cuts, and meat smothered in gravy or other condiments.
if you eat lean meats in moderation like fish, turkey, a little chicken, and a little grassfed beef it is perfectly healthy as a part of a balanced diet. you need fruits and veggies to be balanced though. as much as musky is right you need b12, you also need other vitamins and minerals that are only found in fruits, veggies, and grains. so both sides of the argument are wrong if we are going to go by that basis
I'm pro balanced diet of whole foods, 1-2 hours of exercise per day, and getting 8 hours of sleep a night, with a lot of water .. avoid caffeine/stims, alcohol, rec drugs, and of course tobacco. do that and you will live very healthy