Five days after hosting one of the most spectacular celebrations of privilege ever seen, the Prince of Wales has been telling Americans about the importance of restraint and responsibility. The Western way of food production presented "an increasingly insane picture" in a world facing a crisis of population and the environment.
In the land where the average American eats 41kg of beef a year (almost twice that consumed by the British and four times the international norm), the Prince quoted UN figures which showed that it now takes 2,000 gallons of water to produce a pound of beef. While 2 billion people in the world are deemed to be underfed, 1 billion on the other side of the world are overweight or obese. It was "time to take some very brave steps", the Prince told a Future of Food conference in Washington.
As bad luck would have it, another wealthy food crusader from Britain has just received a knockback in America. Jamie Oliver's attempt to combat the country's addiction to junk food with a TV show called Jamie Oliver's Food Revolution was temporarily pulled from the schedules after four episodes. Viewers tuning in to see how Jamie was faring in his attempts to persuade schools in Los Angeles not to ladle cheeseburgers into their porky pupils found themselves looking at Dancing with the Stars.
Americans do not like to be told what to eat, least of all by well-heeled British celebrities. They see the regular consumption of stomach-stretching amounts of food as one of the rewards of living in the Land of the Free.
The British may talk more about the subject, with the TV schedules constipated with cooking and dinner-party programmes, but a glance at the shape of parents and their children on any high street suggests we too are in for a hefty future. Prince Charles's analysis, and his suggestion that there is something seriously amiss in the way we produce food, is every bit as true for this country as it is for the US.
The UN statistics he quotes are certainly alarming. Global demand for food will increase by 70 per cent by 2050. Food-producing farmland is being lost at an astonishing rate: in America, an area the size of Indiana has been built over since 1982. Around 97 per cent of food bought in America is not grown locally. Biofuel accounts for 40 per cent of corn grown there. Vast corporate-owned food factories and intensive farming of land are even rewarded by government subsidy.
The same priorities are in place here: the "curiously perverse economic incentive system", the emphasis on production and profit at the expense of the land, the pressure for ever-larger factory farms. As for land use, the Chancellor of the Exchequer spelt out government priorities last month. Business should come first. "The default answer to development is 'yes'."
The truth is that, just as individuals can be greedy when they sit down to dinner or look at a menu, so the majority of farmers are greedy when they look at the land which is their bank balance; short-term profit is what interests them, and the same goes for a government for whom a healthy bottom line for business has always mattered more than a healthy planet.
Concerned at how little most people know about the way food is produced, the National Trust has this week invited subscribers to take part in an internet game called MyFarm which will allow those who have paid a £30 entrance fee to vote on decisions affecting a real farm in Cambridgeshire.
It is a nice idea, and feeds the reassuring fantasy of a conscientious farmer, perhaps not unlike the Prince of Wales in rustic mode, weighing up the environmental case against the need to make a living. But away from internet games and well-meaning speeches, it is business as usual. Like a 20-stone fatty settling down to a large T-bone steak, government and the big farming interests are not thinking beyond their own urgent appetites.