considerably worse for your health

Not quite the case. The way we in the western world consume meat is not particularly healthy. But a vegan diet is not healthier per se. You can have a pretty healthy diet that includes meat (although definitely with less meat than the average person in the western world consumes) and you can have a pretty healthy vegan diet. The difficulty with vegan diets is that humans are biologically omnivores, and while it is possible to lead a healthy vegan diet, one does have to be much more careful about their diet so that one doesn't miss any important nutrients. There's a reason the human palate is trained to like meat.

to the environment

This is more an argument to reduce meat consumption than to eliminate it, something I am entirely for. Whatever food we consume, it will just about always have an impact on the environment. The question is how we can reduce that impact to a point where it is sustainable.