I can't help thinking a vegan diet is lacking in certain nutrients, in particular protein, some doctors seem to suggest that and possibly not suitable for a child. I agree with those who say vegan January is all too hair shirt. My son became vegan briefly and said he felt much healthier, he was heavily influenced by a friend when they were sharing a flat, mainly because that friend was at the height of his "born again vegan, meat is murder" phase, he would approach strangers in pubs/restaurants and hector them if he saw them eating steaks and burgers, took over the fridge in their flat and would only sanction his approved non dairy products going into it. Just insufferable he was, I gather he has toned some of that down in spite of remaining a vegan.
When we occasionally go to Pizza Express my favoured pizza, is one of their vegetarian ones that has vegan cheese on it, which I always ask the waiter to substitute with ordinary cheese, their reply is always "oh everyone who orders this one doesn't want the vegan cheese"
My husband's older children were both vegetarian when we got together and it was probably around that time I started to experiment with vegetarian cooking and we often have a meat free meal during the week. I quite understand why people don't want to eat meat. My vegetarian step daughter doesn't like any of those meat substitute foods.