Charisse Jones, and Zlati Meyer

USA TODAY

MARINA DEL REY, Calif. — For years, Carl's Jr. and Hardee's featured sexy TV ads with Paris Hilton and Kate Upton lustily devouring drippy hamburgers. Now the fast-food chain says it wants to grow up.

With its customers demanding higher quality, the restaurant is making changes, starting with a TV ad campaign that openly mocks the sex-fueled formula that led to higher sales for years. It's also revamping its yellow star logo and bringing in a CEO to replace Andy Puzder, who is leaving after failing in his bid to become President Trump's Labor Secretary. The changes are geared toward broadening the chain's customer base.

The dual chain's parent, CKE Restaurants Holdings, based in Franklin, Tenn., is the latest company to adjust to the sizzling pace of change in the fast-food industry. Other giants are also tweaking their menus and images. Just this month, McDonald's executives told investors that they are focusing on improving the quality of the chain's food, particularly its burger and chicken offerings, among other initiatives.

For Carl's Jr./Hardee's, the answer isn't to alter the menu, it's to go a bit more upscale with its image.

CKE'S approach had been to emphasize that it served the kinds of items fast-food visitors wanted, but a bit more upstream to what quick-service restaurants offered; for example, their burgers were one-third or one-half of a pound, not one-tenth, and menu items included hand-scooped shakes and fresh biscuits.

The stakes are high considering the scope of CKE, which has 3,800 franchised or company-operated restaurants in 44 states and 41 foreign countries. Focusing on what Carl's Jr./Hardee's calls its "hungry young guy" demographic, the chain has traditionally catered to people who visit fast-food restaurants most often. By reaching for a wider array of customers, it could alienate the very group that revived what Puzder believed was a dying chain.

“There’s a risk in alienating their old base, because people interested in edgy commercials and edgy branding may not be interested in the new branding,” said Ernest Baskin, an assistant professor of food marketing at St. Joseph University.

Puzder, however, said the new direction is in keeping with changes in the world of fast-food.

"The old campaign got a lot of attention, got people in to see the really delicious burger," Puzder said in a phone interview. But "I think we had to more directly and convincingly" talk about food quality.

The chain recognizes the rise of burger joints like Five Guys, Steak 'n Shake and In-N-Out, which have created an aura around taste -- a quality that Puzder says Carl's Jr./Hardee's has always had, but not fully promoted.

To make the point, privately-held CKE, branded Carl's Jr. in the West and Hardee's in the East, will roll out a fictional character named Carl Hardee Sr., a curmudgeonly founding figure. During filming at an industrial building in Marina del Rey, on the west side of Los Angeles, the ad creates the story of Hardee taking back the chain from his playboy son, whose offices are decorated with blow-up photos of the sexy women and burgers from the chain's previous ad campaigns.

He escorts his son, Carl Jr., out of the offices for a little re-education about the chain's heritage, including its emphasis on premium beef and charbroiling. The ads will air extensively on cable TV stations, aimed at repositioning Carl's Jr. as the place to go for quality.

Also getting a makeover is the physical look of Carl’s Jr./Hardee’s. Its yellow star will no longer have a happy face in the middle of it and the red and white lettering will be replaced by black.

“It looks cleaner and more contemporary,” said Brad Haley, chief marketing officer for CKE. “[It] made it less of a kids' icon.”

The physical look of the restaurants will also change to look more upscale and contemporary, he added. The company declined to show what they will look because those plans aren’t finalized yet.

The image change, masterminded by a Los Angeles-based ad agency called 72andSunny, coincides with a transition in leadership. Puzder, CEO for 16 years, will be replaced next month by Jason Marker, the former president of Yum Brands' Kentucky Fried Chicken in the U.S. Puzder signed off on the new ad campaign before he was nominated by President Trump for the Labor post. Puzder dropped out of the running after hitting opposition in Congress.

Even though Carl's Jr./Hardee's sexy ads surfaced as an issue wielded by his opponents to the job in the new administration, Puzder says he has no regrets. "We don't have anything to be ashamed of," he said. The chain was in deep trouble when he took over and the ads, he says, along with improvements in cleanliness, food quality and service, saved the chain and the jobs of its about 75,000 employees.

In 2016, chain restaurants overall had their worst quarterly performance in more than five years. Sales at locations open at least 18 months dropped 2.4% in the quarter that ended in December, according to retail analytics firm TDn2K. But quick-service restaurants are doing better than most other segments. Low prices, along with new menu items, are key reasons for their stronger performance, said Victor Fernandez, TDn2K's executive director of insights and knowledge.

“Quick service has been doing a better job of increasing their perception of value through improved food offerings and discounting,’’ Fernandez says. They "are concentrating on their core customers who are looking for different things such as value and convenience."

The timing is right for Carl's Jr./Hardee's, said Janet Lowder, president of consultants Restaurant Management Services.

"It would be a good idea to reimage it a bit,’’ Lowder said. "They have a lot of good limited-time offers, a lot of good product promotions. So I think they’re doing things that are in tune with the industry.’’

Contributing: Chris Woodyard

Jones and Meyer reported from New York and Woodyard from Marina del Rey