You can be vegan or vegetarian, its a personal choice, but you have to be the best vegan or vegetarian you can, grow your own crops or make sure they are locally sourced.
I don't think many vegans can do this. They are couch vegans not actual ones.
Also we all use animal products either we like it or not. Killing a meat every now and then for steak doesn't minimize anyone's impact. being vegetarian just makes one more ethically hypocritical.