I think this man would deserve a comment using verbal self-defense techniques, as he was being abusive, but hiding it behind so-called 'humour'. Suzette Haden Elgin, in her books, says that the way to respond to this kind of question is to not answer the ACTUAL question at all, but to recognise the ASSUMPTION behind it, and question that.
So, here, it might be,
'And when did you start to think that you had the right to demand that other people conform to what YOU think is OK as regards food intake?'
Or,
'When did you start to think you could demand that I tell you anything at alll about my preferences?'
Asking a question back to them, instead of just answering their question, also shows that you're not going to comply so easily.
Janet