After years of skipping lunch, King Charles III is now eating a "superfood."
The Mail on Sunday reported that the monarch, who is battling an undisclosed form of cancer, now consumes half an avocado with "some reluctance" to keep his strength up. According to the outlet, the 75-year-old is known to rarely stop for a midday meal unless a royal engagement or official event requires it.
The outlet noted that the king broke his habit of skipping lunch on orders from his wife, Queen Camilla, as well as his palace aides and doctors.
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They also shared that Charles prefers to eat avocados on their own, as opposed to smashed on a piece of toast.
"The king’s doctors, like Charles himself, are big believers in holistic medicine, and adding avocado to the monarch’s daily diet is right up their alley," Christopher Andersen, author of "The King," told Fox News Digital.
"Charles has never eaten lunch," Andersen shared. "’I want to go to sleep immediately afterward,’ he once explained, ‘so I skip it.’ But he more than makes up for it with enormous breakfasts, teatimes and dinners."
According to the outlet, Charles was known to prefer "a brisk walk" to having lunch. He previously told the BBC that he abstains from meat and fish two days a week. He also excludes dairy on one of those days.
Andersen, who interviewed several palace insiders for his book, noted that the meals the king does eat "have always been served to meet his exacting standards."
And there is zero room for errors, he claimed.
"According to a longtime servant, Charles’ breakfast tray always had to contain a cup and saucer to the right with a silver spoon pointing outward at an angle of five o’clock," Andersen explained. "Butter must come in three balls – not pats of butter, but they must be balls of butter, and they must be three in number. They must also be properly chilled, or they are sent back."
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Andersen pointed out that presentation is crucial when it comes to any meals the king consumes.
"The royal toast is always on a silver rack, never on a plate," Andersen claimed. "Assorted jam, jellies, marmalades and honey are served on a separate silver tray. The king also insists on round ice cubes in his drinks because he thinks squared cubes are too noisy. Breakfast also includes cereal and cut fruit – all small portions. Charles ‘hated large portions,’ the servant revealed, and goes ‘absolutely crazy’ whenever he is served in the U.S., where large portions are the norm."
Charles does have a guilty pleasure, said Andersen. The author claimed he loves indulging in a "highly caloric fruitcake from Wales."
"Butter must come in three balls – not pats of butter, but they must be balls of butter, and they must be three in number. They must also be properly chilled, or they are sent back."
And while the king may forgo a midday meal, dinner is always "a big affair."
"It often consists of game he has shot at one of the royal estates," said Andersen. "Regardless of the main course, dinner always includes a green salad with a soft-boiled egg. The egg must be cooked to meet the king’s standards of softness. And it’s never met on the first try. On occasion, a half-dozen eggs are sacrificed in the process."
"Dinner guests at Clarence House, Windsor, Balmoral, Sandringham and Highgrove have been surprised that His Majesty often eats a meal that is entirely different from theirs, prepared especially for him," said Andersen. "The king refuses to use a saltshaker. A small silver bowl of salt with a silver spoon is always provided to him, wherever he happens to be dining.
"‘My people take such good care of me,’ he once said when the bowl was brought to him at a Windsor dinner. ‘They always bring my salt.’"
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"By the same token, woe be unto the butler who does not make His Majesty’s dry martini precisely to the sovereign’s liking. As far as alcohol is concerned… before his cancer diagnosis, of course, he would normally consume three or more drinks – a martini before dinner, perhaps, followed by wine and an after-dinner drink. This is nothing compared to the six or seven drinks the Queen Mother would regularly consume in any 24 hours. It worked for her – Charles’ granny lived to be 101!"
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"It is understood that, as he undergoes cancer treatment, he has cut back on his alcohol intake dramatically, but is still allowed the occasional drink," Andersen continued. "King Charles has always been a bundle of quirks and idiosyncrasies. Adding a daily dose of avocado to the mix for health reasons seems like one of the saner things he’s done when it comes to eating habits."
Charles is preparing to visit Australia and Samoa in October, Buckingham Palace announced in July. The monarch has been slowly returning to public duties after taking a break following his cancer diagnosis in early February.
The decision to undertake such a long journey will be seen as a sign of Charles’ recovery, even though the program in Australia will be "limited."
Tom Parker Bowles, the king’s stepson, recently gave a brief update about the monarch’s health to British Vogue. The food writer told the outlet that the king is receiving "the best treatment," but admitted that cancer is "really a bastard."
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"The king’s having the best treatment," said the 49-year-old. "He’s a great man and a tough man, and you’ve just got to get on with it. Of course, anyone who has someone they love with cancer is going to worry."
The Associated Press contributed to this report.