Credit: Dimitrios Kambouris/

Betty White's secret fountain of youth? A diet fit for a teenager!

"She eats crap," her Hot in Cleveland costar Jane Leeves told at the icon's 89th birthday party. "She eats Red Vines, hot dogs, French fries and Diet Coke. If that's key, maybe she's preserved because of all the preservatives."

Seconded fellow Cleveland costar Wendie Malick, "She eats red licorice, like, ridiculously a lot. She seems to exist on hot dogs and French fries."

All the junk food seems to fuel the actress' busy schedule.

"Everybody says my career is resurged," White told Us. "But I haven't been away, I've been working steady!"

Her tip for starlets trying to achieve her level of longevity: stay smart. "Be a professional and appreciate the business your in," she said. "Everybody all over the world would love to be in your business, so don't abuse it!"

Still Leeves told Us, the former Golden Girls star doesn't shy away from a wisecrack or two.

"She's got a salty mouth, that woman, and she's always delighting our crew," Leeves said. "She's always with the quick wit. Probably nothing I could say out loud."