State banquets already come with their long list of royal rules and requirements, but you might be surprised to hear that King Charles maintains some of his own personal demands behind closed doors, too.
Far from pomp and circumstance, one thing reigns supreme with the monarch's balanced diet - there must be no waste, according to Queen Camilla's son, Tom Parker Bowles. "There is no waste, everything is recycled, everything is used from the table," he said in an interview with The Mirror.
"If anything is leftover from the dinner, that will be made into something else or appear the next day. Nothing's allowed to be thrown out."
This has manifested itself in unexpected ways, such as Charles converting his Aston Martin sports car, which was a 21st birthday gift from his late mother, Queen Elizabeth, to run on a combination of surplus English white wine and whey from cheese as a form of fuel.
The sustainability commitment even seeps into their afternoon tea habits, per The Telegraph. King Charles and his wife, Queen Camilla, reportedly insist on being served the same slices of the same cake throughout the week until it is finished.
Since the monarch has a penchant for fruit cake, which is preserved thanks to its high concentration of fruit to flour ratio, it lends itself to longevity.
Sustainability 'hero'
© UK Press via Getty ImagesKing Charles has long championed sustainability, having founded the Coronation Food Project in 2023 with an aim to combat food insecurity in the U.K. According to the 2025 impact report, it had rescued 4,932 tonnes of food, which was the equivalent of 11 million meals.
"It's not the king just paying lip service, he practices what he preaches," Tom added, referring to the project. "He really is a food hero. To talk to him about the strange varieties of plums or pears or anything else is endlessly fascinating."
© Getty ImagesIt has long been his mission to raise awareness of the issue. Back in 2010, the then Prince Charles pointed out the "immense" waste accounts to around "10 billion quid's worth a year."
He added to The Telegraph: "That is immoral again. When people shout and scream that you can’t feed the world on sustainable approaches to farming, it’s absolute nonsense – an organic approach can increase yields enormously."
Personally addressing his own carbon footprint, he previously confessed he had made changes to his diet. In the interview with the BBC in 2021, the royal said: "I haven't eaten meat and fish on two days a week and I don't eat dairy products on one day a week. If more did that, you would reduce a lot of the pressure."
