From personal experience of when I went vegan for a year and rode a bike everywhere, people really don't want to hear it. I went out of my way not to talk about it unless people specifically asked me about it, and even then, they didn't want to hear it. Regardless of what you say when questioned, they either think you're sanctimonious and/or they will start associating their guilt and negative feelings with you. The end result is that you start getting frozen out. If you no longer eat meat, you stop getting invited to the BBQ, or the meal at the steakhouse, and when you stop getting invitations to these events, you stop getting invites to others because you're getting pushed further and further to the periphery. People are tribal and they don't want to feel bad about things they enjoy. It is far more likely that you will get kicked out of the tribe rather than the tribe changing it's behaviour to match yours.