Going vegetarian for ethical reasons is one of the best ways to really stick with it. Health is a wonderful side effect of being veg.

You aren't vegetarian if you eat meat at all--even in small quantities. You could cut down substantially for your health and the animals but then accept that you are still a meat-eater.

Eat faux (soy) meat in front of your daddy, then when you get out on your own confess to being vegetarian. It wouldn't hurt for him to cut down the meat intake, given the genetic obstacles you mention and health statistics.