King Charles advocated for the benefits of eating well amid cancer treatment at a Buckingham Palace garden party

Stamford told the Daily Telegraph newspaper: "He was asking me about the treatment I have starting in June and spoke to me about food and diet. He also asked me if I had undergone radiation treatment, which I had earlier this year."

The publication reports the king was heard to say: "It's sometimes about the diet and what you eat. It can help."

Charles was joined by wife Queen Camilla at the event, which was held in recognition of those working in education and skills.

Guests mingled in the blazing sunshine while enjoying performances from Royal Ballet school students, the British Army Band Catterick and the Band of The Royal Air Force Regiment.

Camilla, 77, expressed her concern for guests being out in the heat.

She told one partygoer: "I hope you aren't too warm. I do hope you have had the chance to put your feet up and have a drink."

The King was "in his element" talking about crafts as he spoke to Patricia Alban, who set up Sammy's Foundation in memory of her son, a keen carpenter and upholsterer who suffered from Prader-Willi Syndrome and autism died in 2020 aged just 13.

Patricia - whose foundation helps young people suffering from neurological conditions learn high-end craftsmanship - said: "I told Sammy, 'One day I will meet the king and tell him about you.'

"And here I am. I can't believe it. He would have been so proud. I feel quite emotional. I feel like he is there. It's been a dream of mine.

"His Majesty was in his element talking about crafts, it is something he is passionate about. And he was suggesting people and organisations I could talk to."