Zaftig Kirstie Alley says she's shed 55 pounds through a weight-loss dance routine — and admits she ballooned to 219 pounds before deciding to lose some weight.

Alley was on yesterday's "Oprah" with her two personal dancers, showing off her weight- loss dance and telling Oprah Winfrey about her new life as a slimmer woman.

"I really wanted to celebrate that I had gotten thinner," Alley told Winfrey about her dancing regimen which, she said, she's going to translate into an instructional videotape.

"I really love doing this," she said. "It just makes you feel like you're in a celebration."

Alley, who starred in "Cheers" and "Veronica's Closet," gained tabloid notoriety by packing on the pounds in recent years.

She even spoofed herself in the Showtime series "Fat Actress," a quasi-real look at her life in Hollywood as a plump performer.

Her revelation that she once weighed 219 pounds was the first time Alley ever admitted how much she'd gained.

"I made some good decisions simultaneously with bad decisions . . . I wanted to spend more time with my kid. I wanted to cook," Alley said about her weight gain.

"And this is the dumbest decision I've ever personally made in my life. It went like this: Like if a man really loves me, he will not have to love me for my, you know, my body.

"He will really love me just for me," she said. "Don't ever do this . . . that was the biggest stupid mistake I ever made.

"When did I decide I was this big fatso?"

Alley, who's now a spokeswoman for Jenny Craig, said she wants to shed another 25-30 pounds.

"I'm gonna keep dancing," she said.