Not a vegan myself, but I'm an atheist.
I've heard a lot of criticism about veganism by atheists in the past, and never really understood that. Apparently, a lot of veganism theory depends on pseudoscience?
I don't know, but you seem to be a pretty levelheaded person. I've got a vegetarian girlfriend, you people just seem to eat plants instead of animal products, not really something that one can truly disprove of, right?
Glad to see another atheist here :)
Peace!