Talking to US Weekly, Wendie Malick and Jane Leeves said that the 89-year-old is constantly seen eating "crap" while on set and seemingly lives on fried foods and candy.
"She eats crap. She eats Red Vines, hot dogs, French fries and Diet Coke," Leeves said. "If that's key, maybe she's preserved because of all the preservatives."
Malick added: "She eats red liquorice, like, ridiculously a lot. She seems to exist on hot dogs and French fries."
However, White insisted that her longevity is based on working hard and staying humble.
"Be a professional and appreciate the business you're in," she advised. "Everybody all over the world would love to be in your business, so don't abuse it!"