He's a tireless champion of organic farming and healthy eating.
So it was perhaps no surprise when Prince Charles launched an attack on the fast-food industry.
But when he went as far as suggesting that McDonald's should be banned, it seemed that the prince had bitten off far more than he could chew.
He immediately laid himself open to charges of hypocrisy after it was pointed out that the company's signature Big Mac contains fewer calories, fats and salt than some products in his own organic Duchy Originals food range.
How they compare...
His Cornish pasty contains 264 calories per 100g compared to the burger's 229 calories, and 5.5g of saturated fat as opposed to the Big Mac's 4.14g.
The prince's comments regarding McDonald's, the world's biggest fastfood chain, came during an event to promote better public health on the penultimate day of his tour of the Gulf.
Charles met nutritionist Nadine Tayara at a new centre to combat diabetes in Abu Dhabi set up by Imperial College London.
Miss Tayara was showing him how local schoolchildren were being encouraged to put fresh fruit and salads in their lunch-boxes each day instead of eating fast food, when he remarked: "Have you got anywhere with McDonald's? Have you tried getting it banned? That is the key."
His off-the-cuff remark immediately put him on collision course with the company, which has not shied away from issuing lawsuits against critics in recent years.
A McDonald's spokesman said the company was "disappointed" at the prince's remarks and pointed out that several members of his family have been regular customers over the years.
The spokesman declined to comment on the relative "healthiness" gap between the royal pasty and the company burger.
Prince Harry was recently photographed nipping off from a polo match to buy a burger and some chicken nuggets and, as a boy, was a regular visitor to the fast food outlet with his mother, the late Princess of Wales, and brother William.
The Prince was accompanied by his wife, the Duchess of Cornwall, to the Imperial College London Diabetes Centre. The facility opened in June last year with mainly British medical staff and specialises in the treatment of diabetes as well as research and education.
A Clarence House spokesman said after the visit: "The Prince of Wales believes very strongly in the importance of a balanced diet for everyone, especially children.
"In visiting the diabetes centre today, he was keen to draw attention to this very important issue, particularly the need for children to enjoy the widest possible variety of food and not eat any particular food to excess."
But the spokesman declined to discuss claims that a Big Mac was, in fact, healthier than one of the Prince's own Cornish pasties, saying that the Duchy Originals brand openly recorded the nutritional content of its products. "It is up to consumers to decide whether to buy them," he said.
Diabetes has become a huge problem in Abu Dhabi, part of the United Arab Emirates, in recent years with 25 per cent of the population suffering from the disease
Doctors believe this is due to the population switching from a traditional diet to a Western one, high in saturated fats and sugar.
Penny Mordaunt, director of nations, regions and campaigning at Diabetes UK, said of the prince's comments: "Diabetes UK does not believe that banning fast food is the answer to improving people's diets and in turn reducing obesity and diabetes.
"Realistically, it is not practically possible to prevent people from getting hold of any sort of food. Good education about the damage a diet high in sugar, fat and salt can do is the best way to encourage people to change their eating habits."
A spokesman for McDonald's said of the prince's comments: "In our opinion they appear to be off-the-cuff remarks that do not reflect either our menu or where we are as a business. Other family members have visited us and they obviously have a more up-to- date picture of us."
The spokesman pointed out at the fast-food chain had, in recent years, introduced new choices such as salads, semiskimmed organic milk, fruit and carrot sticks as well as reducing the levels of salt in its meals.
She added: "We have also improved the nutritional information we provide."
Daily Mail nutritionist Jane Clarke said: "While I would prefer to eat one of Prince Charles's cornish pasties because the meat is far superior to a fast food giant, it doesn't surprise me that the actual fat and calorie levels are higher than most people realise."
The Royal pasty that's unhealthier than a Big Mac | News | This is London