Welcome to the Forum. I haven't much idea but Googling Switzerland Food Import Regulations brings this page:
This from Swiss Customs Administration
and this bit in particular:
Foodstuff ready to eat and non-alcoholic beverages for the day of travelling.
Whether the sixty of them can convince the customs officials that 50 Mars Bars, 62 Crunchies, 78 packets of crisps (cheese and onion please) or whatever else the youngsters these days eat is 'food for the day of travelling' is anybody's guess. If they have children of their own who take part in sport, they'll probably accept it without batting an eye-lid.
Good luck to them all.