Obese people are showing up in the very place that's mostly excluded them for decades: ads.

Some of the nation's largest brands – from Nike to Subway to Blue Cross Blue Shield – are featuring images of obese or overweight folks in their advertising in a bid to change consumer behavior. (Obesity is considered to be anything 20% or more over ideal weight.)

The move comes at a time almost two in three adults are overweight or obese, and diseases caused by obesity cost Americans $145 billion last year. In the past, when obese folks showed up in ads, they were often the butts of jokes. Now, they're visual images for change.

Why is it now acceptable to show obesity? "More of us are overweight, so it's a shared problem," says Valerie Folkes, marketing professor at University of Southern California.

It's a generational thing, too, says brand consultant Erich Joachimsthaler. "The new generation doesn't see (obese people) as different. There is a new, democratic world view: Everyone can be a star."

Among those showing obesity:

* Blue Cross Blue Shield of Minnesota. The health provider has two new ads with obese actors. In one, an obese father with a tray full of fast food thinks twice when he overhears his large son arguing with a fat friend over whose father can eat more. The second features a young girl following her mother in the grocery store and picking up the same junk food and putting it in her kiddie cart.

"People have to make choices about food every day," says Marc Manley, chief prevention officer. "We want to give them encouragement to make healthier choices."

* Nike. The shoemaker launched an ad this summer showing an obese runner jogging.

"It's not just championship athletes that aspire to push their limits," spokesman KeJuan Wilkins says.

* Subway. In March, the sandwich chain will celebrate the 15th anniversary of Jared as its spokesman by congratulating him for keeping svelte. The ads will feature old photos of him at 425 pounds. "It's hard to lose the weight, but it's even harder to keep it off," says Tony Pace, head of Subway's marketing arm.

But the message can get murky, says James Zervios, spokesman for the Obesity Action Coalition, a non-profit representing obese people. "It's a fine line," he says, noting that marketers need to be careful of stereotypes linking all obesity to overeating. "So far, they're staying on the positive side of the line, but it's easy to cross over."

USA Today