MIAMI - Jamie Oliver is using fresh fruit and vegetables to try to win the hearts, or at least the fatty arteries, of a West Virginia city. Rachael Ray is working to reform school lunch. And Paula Deen, queen of Southern-fried goodness, recently taught an auditorium of kids how to cook and eat healthy.

Chefs have always wanted us to eat something good. Now, it seems they're just as interested in seeing that we eat well.

"They're digging down to more substance, which is great because we all win," says Phil Lempert, the food marketing expert known as The Supermarket Guru. "Before it was cleavage and being cute to get noticed. Now it's all about substance, nutrition."

This didn't happen overnight.

Pioneers like California chef Alice Waters and, more recently, journalist Michael Pollan have been preaching the gospel of fresh, unadulterated food for years.

But when everyone from Deen to "Dancing With the Stars" alum Rocco DiSpirito is talking about the benefits of produce over processed you know the tent has gotten a little bigger.

"It became clear to a bunch of us that not only is it a good idea now, but people are ready to be receptive," says DiSpirito, author of the recent New York Times' bestselling healthy cookbook, "Now Eat This!"

That's partly because the rock star status TV chefs enjoy gives them an entree into American kitchens that previous proponents of healthy eating lacked, notes Lee Schrager, founder and organizer of the annual South Beach Wine and Food Festival.

Oliver, for example, is headlining "Jamie Oliver's Food Revolution," an ABC reality show documenting his efforts to change eating habits in a community the network calls the nation's unhealthiest.

Chefs are realizing they have a responsibility to use their influence to foster change, Oliver says. And celebrities often can do that with more panache than traditional nutrition advocates have.

"You don't want to food nazi the fun out of everything," he says. "You can still cook great things that are calorific, but you just need to intro it with kind of - Look, this is a special occasion, or this is for the holidays, or whatever."

Snappy titles and glamorous stars are new tactics for the eat healthy movement, which in the past has been perceived, fairly or not, as fun-deprived. Even Sesame Street is reaching for star power. The program recently named Art Smith, Oprah Winfrey's former chef, as its healthy eating adviser.

"It's becoming less elitist," says nutrition and policy expert Marion Nestle, who credits first lady Michelle Obama's championship of healthy eating with helping take the issue mainstream.

Deen agrees. "We work on unintimidating foods that mothers and dads can put together pretty easily," she says.

Now there even is a glossy food magazine dedicated to helping kids eat and cook healthier. The just launched quarterly ChopChop Magazine is aimed at 5 to 12-year-olds.

A tipping point in the debate seems to be child obesity, the focus of the first lady's campaign. A nation that can gaze with equanimity at racks of XXL clothing for grown-ups has grown less tolerant of needing "husky" jeans for 5-year-olds.

At the recent South Beach festival in Miami, an event for 50,000 people where $300 tickets are the norm and Champagne flows freely, obese kids might seem off-topic. But Schrager worked them into the schedule for the third year, adding a healthy eating fair for children at a nearby zoo. For $20, families could spend the day learning about healthy eating and watch cooking demos by Food Network celebrities such as Ray and Deen.

"Everything has to change - access to food, attitudes, education," says Ray, who designs healthy recipes for the New York City school lunch program and started the Yum-o! charity, which raises money to teach kids healthy eating.

Even the message itself has changed. Low-fat and low-carb are so last century. Today, it's about balance and real foods.

"It's far better to eat a balanced diet of full-fat whole foods than it is to eat no-fat, low-fat or fake foods where they've replaced fat with fillers and stuff like that," says Ray. "And I think that one of the benefits of eating a balanced diet is that you can eat some of the things that are not so figure-friendly some of the time," says Ray.

Still, even celebrity-driven change doesn't come easy.

Oliver, in the early episodes of his new show at least, has made some converts but also gotten pushback from people who don't take kindly to an out-of-towner overhauling their diets.

But, he says, it's an effort worth making.

"One doesn't want to suck the life or fun out of food because that would be wrong. But, you know, I think the general world of food - chefs, celebrity chefs, fast-food industry, supermarkets, the 'government food gang' - they all need to do a bit. Hopefully, a bit more than a bit. And if they do, the world will change."