@Thinkstock: dulezidar
The Only Forbidden Food was...
Garlic. British Chef Carolyn Robb who cooked for King Charles III, Princess Diana, Princes William and Harry from 1989 to 2000, was not allowed to serve them anything with garlic. Not because they didn't like it but because of their constant public appearances, events and meetings, which made for lots of talking to people up close (aka not ideal when you have garlic breath). Chef Mcgrady also said the Queen hated the smell and taste of garlic, so that probably had a lot to do with it.