Dunkin' Donuts is far more prolific than McDonalds

"America loves Dunkin' Donuts and Dunkin' Donuts loves America. It's frightening." These were the words of a genuinely concerned diabetes researcher at Harvard who happened to be walking in the same direction as I was one evening two weeks ago in Boston. "I don't know what it's going to be like in five, ten or twenty years," she said to me, "but it seems impossible to change American attitudes to food." Coca Cola posters in subway stations appeal to the residents of (what is nonetheless) one of America's healthiest cities by showing a chef leaning over an elegantly presented cordon bleu meal and a bottle of the ubiquitous soda. The caption reads, "Good taste is knowing how to have it all."

In the filming of his first TV series for US audiences, Jamie's Food Revolution, Jamie Oliver has set himself a difficult challenge, but one which smacks of his characteristically plucky charm. Can he do for Americans what he did for British school children with his defiantly progressive series Jamie's School Dinners? New obesity rates for the USA were published over the summer and they tell a familiar story - but one which is frustratingly disappointing for the energetic groups in America who have been consistently trying to raise awareness of obesity, diabetes and heart disease. For them, news that levels of obesity rose in 23 states and fell in none will be difficult to digest, and the shocking statistic that nearly 70 million Americans are now clinically obese will only serve to make their task seem more insurmountable than ever.

Perhaps the seeds of Jamie's new venture were sown (or fertilised) back at the G20 summit at the beginning of the year. After cooking for recession-weary world leaders at Number 10 it was an American, Michelle Obama, who suggested the state guests thank their chef by asking to be introduced to him. The plucky 'Essex boy' had a chance to get through. Oliver has frequently stated that he sees diet-related illnesses as one of the greatest threats to mankind, and the above figures will no doubt be at the forefront of his mind as he sets out to tackle bulging American waistlines and an ever-dwindling appreciation of home cooking.

In fact, the size of the task he has set himself is almost laughable. Uncovering the "real food" descended from immigrant communities and early settlers was the premise at the heart of his American Road Trip series, but as Oliver films a new show for rather than about Americans, he doesn't only need to encourage healthier diets, but bring those authentic ones more fully into view. The Coca Cola ad is acutely indicative of the broader American food culture. That is, a culture which has imported, branded and industrialised every major international cuisine on the planet. The lie in the illusion of choice and diversity - and in the assertiveness of the Coca Cola campaign - is that "having it all" means, of course, having American descendants of real food cultures whose authenticity has been boiled down to an economically viable and hesitantly familiar version of "the real thing." Would Oliver approve? I doubt it. It's clear that he's been able to find better examples of American eating on his travels, but it's also clear from his string of books and TV programmes that Oliver yearns for a western culture which takes much more time over food, making the effort to grow its own produce (Jamie at Home) or obsess over the authenticity of imported cuisines which have been standardized and dumbed-down elsewhere in recent decades (Jamie's Great Escape).

The problem is that Oliver has to work within the medium. He's already been subjected to over-the-top reality TV melodramatics in appearances on shows like Iron Chef America last year (see above) where the lispy Essex cook appeared out of a blurry haze of studio spotlights and toe-curlingly bad drum-and-chorus tension music. A few weeks ago, the well-meaning and much fluffier Good Morning America of ABC treated Oliver more seriously, but even here the star of slash-it-up-and-bung-it-in cooking was a little out of his depth managing larger-than-life American TV personalities and an eye-searingly colourful kitchen to boot. And don't forget that his readiness to tell people what to eat was by no means universally popular at home. Americans are even less likely to appreciate Oliver's head-strong approach immediately.

Oliver's international empire is growing

We all know that some Brits are instantly and lovingly adopted by American audiences while others are not. As the UK's most publicised chef, Oliver has become the most industrialized of all our home-grown culinary personalities himself. 'Jamie' is a brand which echoes many American lessons in personality marketing and it seems like a natural and timely progression to take that brand state-side. JamieOliver.com recently reported that the crusading cook has made a bet with a local DJ in one of the least healthy parts of America that he can get 1,000 Americans to cook and eat one of his recipes and send Jamie's ever-busy team a picture of themselves enthusiastically doing so. Here is a classic culmination of Oliver-style audacity and PR melded into perfect unison. And isn't it just the sort of thing the yanks go for?

From what I could tell from a handful of conversations and a sweep of local media, Oliver looks set to woo his audience using tactics like this. "Loved it!" an intensely talkative computer programmer opined, when asked what he thought of a Jamie TV appearance where the chef showed a group of awed US school-children how much fat they consume, on average, every year. A day or two later, a staunchly vegetarian girl on a bus from New York City hands me a special food-themed edition of the New York Times Magazine and tells me to read a pro-veggie feature story inside. I do, but I'm also distracted by Oliver's face on the front of the mag and flick to the cover story which turns out to be a wholeheartedly positive baptism of Oliver's attempts to get the richest nation on earth to start thinking about what it eats. "He seems really great!" the girl says, tucking in to a store-bought salad which she admits is "terrible."

Food Revolution airs early next year on the ABC network. As a TV program, it'll no doubt be a success. But as a catalyst for change, the fruits of Jamie's labour will be a lot more difficult to measure. America will never completely relinquish its love of convenience eating - that is, after all, one of its most successful innovations and a key stimulant in the everyday economy. The point of it all lies in how much Oliver can get his audience to think outside the pizza box a little more frequently and develop their culinary imaginations. So far he's played by their rules without necessarily compromising on his ideals, but the proof, as always, is in the pudding.