In his 42 years, Ronald McDonald has played many roles from burger pitchman to parade grand marshal to child role model. He's been the walking, talking embodiment of youthful play and fun for Brand McDonald's.

But playtime is over. As McDonald's Corp. faces increasing scrutiny over child obesity, it has done what it's always done: send in the clowns, albeit this time more physically fit ones.

The brand mascot that began as the "newest, silliest and hamburger-eatingest clown" was remade last month as the "global ambassador of fun, fitness and children's well-being."

Admittedly, this isn't the first time Ronald has evolved with the market. For years, McDonald's has wanted to tap the power of Ronald's equity and broaden his appeal. Yet this current transition that has Ronald touting health instead of hamburgers to youth of all ages morphs Advertising Age's second-greatest ad icon of the 20th century from kid entertainer to a corporate mouthpiece for the societal issue du jour.

And many Ronald watchers feel the clown has been seriously miscast.

"Ronald was created as McDonald's symbol to children, and everything good that was built up around Ronald was for kids. Once you start making a character for adults [in addition to children], kids by definition won't like him as much," warns Roy Bergold, the former McDonald's VP-chief creative officer who supervised the Ronald program for 30 years. He adds: "Trying to take a character firmly ingrained with 0-to-7-year-olds and make him appeal to the 11-year-old or the 22-year-old is nuts."

Mr. Bergold admits he hasn't read the company research for four years since retiring, but other industry watchers agree with his view.

It's rare for an icon to take on a different personality, says Kevin Keller, professor of marketing at Dartmouth's Tuck School of Business. "Plus, he's a clown who was well-suited for 3-to-6-year-olds. To change the role or broaden the role stretches the personality dramatically ... when you take literally on face value that notion of talking about obesity [it] seems like a bit of a stretch. They can try to make him seem like a more well-informed spokesperson to the young kids if you address it in the right way, but I can't imagine pitching him to an older audience."

DOUGHBOY TALKING CARBS

"You wouldn't make the Jolly Green Giant talk about the nutritional value of peas or have the Pillsbury Doughboy explain carbohydrates," says one industry executive, adding that the strategy to expand Ronald's target audience around the values of fun and happiness seems appropriate, "but this looks like an overcorrection."

McDonald's believes Ronald is ageless and the perfect personification of the "Forever Young" attitude.

"We've gone back to Ronald's biggest strength," contends Larry Light, exec VP-chief global marketing officer, adding that Ronald has been at his most effective when he talked to families about safety belts and literacy.

"The issues have changed. ... he is comforting, happy and earns trust ... having him deliver a message as he has done before," Mr. Light says. "He isn't just an entertainer; he's played a unique role in educating people."

In 2003, McDonald's unveiled a new title for Ronald as "chief happiness officer," who was set to pop up in unexpected places. Insiders say McDonald's has other plans in the works for Ronald and will try to revamp his friends in McDonaldland as well.

Max Cooper, the chain's first public relations adviser and marketing executive turned franchisee, calls himself the "midwife" of Ronald and supports the clown's latest role in the balanced lifestyle initiative. He says McDonald's has managed Ronald's equities well because it's protected his image, making minor tweaks over the years rather than significant changes.

"We're maligned because we're big," Mr. Cooper says. "Nobody targets the all-you-can-eat-buffet."

McDonald's means business with its fitter Ronald. At the worldwide convention of Ronald McDonalds last year, Mr. Light threatened to fire clowns who didn't get fit. "He threw a jump rope at each of them and said to get to 6 feet and 187 pounds," says one attendee.

"Ronald has to be an effective ambassador of fitness," says Mr. Light, adding that he spoke strongly at a meeting of talent agents-not clowns. "He has to be able to be a symbol of [the balanced and active lifestyle message]," Mr. Light says. "He has to be active as well."

MARATHON MAN? NAH

One entertainer who claims to being "Ronald's helper"-insider parlance for being a Ronald McDonald-for at least a decade notes that the requirements go both ways. "You don't have to be physically fit like to run a marathon, you just have to not be really heavy," he says. "Skinny guys have to put on weight."

The new era of Ronald may also be taking its toll on the Golden Arches' vibrant clown culture, which is said to encompass more than 200 Ronalds in local markets, though the official line as stated by Lisa Howard, director-media relations, is "There's only one Ronald."

The field Ronalds (known as Toms for Top Of Mind) traditionally played a key role in developing skits and programs. Today, insiders say, marketing staff, agency executives, and professional writers and creative directors set the tone for most of the programs, which the Toms must execute as prescribed.

The Toms credit longtime "boss clown" Aye Jaye (his legal name) for giving the Ronald program its credibility. In 1972, Aye Jaye and Mr. Bergold penned the handbook "Ronald & How," spelling out the rules of clowning for the chain. Another book each clown received, titled "The Golden Rule of Schmoozing," was written in 1998 by Aye Jaye. Toms call it their unofficial set of rules.

In the past, Ronalds would perform "get up and go" shows encouraging kids to be active, as well as shows with safety and reading themes. Now, being active is the main thrust, says Aye Jaye, who took his bow in 2000 after 35 years as a field Ronald and boss clown for 30 years.

Ronald's new role in teaching balanced lifestyles puts Toms in a potentially awkward position of creating expectations of expertise in exercise and nutrition. When asked for information that stretches beyond the scripted programs, Toms direct people "to ask someone with regular shoes" or look at the nutrition chart in the store, insiders say.

"We're being part of a more targeted campaign now rather than as an overall goodwill ambassador," says the active Ronald. "It's more of a bottom line feeling than a community feeling."