I am vegan and recently I had quite strange lucid dream with this subject.
For those who are not familiar with lucid dreaming I will explain it shortly.
Lucid dream is kind of dream where you are fully aware of the fact that you are dreaming and so you can act consciously.
In fact your body lies in bed, sleeping but your mind is inside dream world, consciously interacting with dream environment.
Normally people when dreaming thinks that what they experiencing is reality. In lucid dream they know that it is only a dream.
More on https://en.wikipedia.org/wiki/Lucid_dream
So in my lucid dream I was in kitchen with my wife and kids (they are not vegans) and my wife was serving yoghurt to kids.
I said to myself that because it is only a dream I can take one as well. I took it, it was very tasty

But after maybe fifth spoon I realized that even though that yoghurt exists only in my head, I am failing to be what I want to be.
I am failing to be vegan. So I stopped eating it and continued in my lucid dream.
Now I am still wondering whether I had overreacted or not.
Of course technically I am still vegan and I will be even if I will eat meat, milk and eggs in every lucid dream in future.
On the other hand It seems to me that when eating yoghurt in lucid dream, I was somehow accepting whole concept
of dairy industry and so it is not something that I want to do in the future.
What do you guys think? Would you eat non-vegan food in your lucid dream?