Don't get me started on nut allergies, last few flights banned as one person had an allergy. They should ask these questions when booking a flight so then nut allergy people can all fly together and not inconvenience everyone else.
Entirely parents responsibility, take example A from recent holiday:
Fat woman with two fat kids, she had a t-shirt on saying "Choose Life" , Mrs Hut said she surely choose food end of.
Two fat kids, at breakfast boy had seven sausages on his plate plus bacon, eggs etc, girl had 5 pancakes...