From the day I learned about the fact you can live healthily without eating meat, I started doubting my alimentary habits. Still, I had a lot of cognitive dissonance and "smart answers" which kept me in this kind of meaty diet. Hey, I really liked meat. I'd still like the taste, I'm sure. I was particularly into beef escalopes and chicken à la crème.
But after a short discussion with a vegan, I realized I was wrong and changed my ways. In 2014, I became vegetarian.
Then I learned more about the meat industry, and learned you just need to take some pills of B12 vitamins at a pretty casual rhythm, and to care a little about iron and proteins by eating the right vegetables, in order to go vegan. And I said goodbye to cheese. I loved cheese too, fondues and raclette. I'm French, so you can guess how much cheese went in my diet.
So now I'm vegan. I don't see particular benefits to it besides ethical consistency, which is a nice thing by itself.
Ingwar is right. We humans do not need to eat meat, so we shouldn't eat meat because meat is produced through the suffering and death of countless animals and the ecological impact of the useless meat industry is simply disastrous, unacceptable in these contemporary days of global warming.