KIRSTIE ALLEY re­cently confessed on the “Today” show that she wants to lose 30 pounds, but sources tell The ENQUIRER the “Fat Actress” has packed on 50 – and now medical experts are warning her to diet or die!

“I’m not circus fat,” Kirstie told Matt Lauer on April 7. “I want to lose 30 pounds. That’s a lot!”

Now weighing in at 250 pounds, the 5-foot-8 star is heavier than she’s ever been and so desperate to shed the extra baggage she’s signed on with Jenny Craig again.

“Kirstie has swallowed her pride and rejoined Jenny Craig,” said an insider. “She’s well aware of the dangers of being overweight and is pre­pared to deal with her issues once and for all.”

According to experts con­sulted by The ENQUIRER, those dangers include deadly health risks.

“She’s headed for a pre­mature death,” said Dr. Gabe Mirkin, author of “The Healthy Heart Miracle,” who has not treated Kirstie.

“All those years of yo-yo diet­ing have made her fatter than ever. You can see by the fat around her middle that she probably has ‘metabolic syn­drome,’ which puts her at risk for diabetes, a disease that increases the risk for cancer, heart attack and stroke.

“If she was my patient I would say to her, ‘You’re going to die unless you change your habits.’ And that means eating less and exercising – not fol­lowing yet another so-called diet program that doesn’t work in the long term.”

Kirstie, 63, lost weight when she first joined Jenny Craig in 2004, but the company dumped her as its spokesper­son three years later when the pounds started piling back on.

The two-time Emmy win­ner weighed a whopping 230 when she signed on with “Danc­ing with the Stars” in early 2011. But by September of that year, she claimed to have dropped to 140, going from a size 16 to a svelte size 8.

And that kind of weight-loss roller coaster puts her at a high risk for serious health issues, emphasizes another weight-loss expert.

“The yo-yo dieting over the years may have damaged her heart and other organs,” said Dr. Aaron Tabor, a weight-loss expert who has not treated Kirstie. “So she’s at risk of heart arrhythmia and stroke unless she embarks upon a sensible, long-term weight-loss program.”

During her recent “Today” show interview, Kirstie joked with Matt Lauer that she wants to visit the NBC morning show’s set once a week until she can “stand here naked and proud in front of the world.”

And she tried to make light of her recent dramatic weight gain, telling The ENQUIRER: “Dudes, you have been predict­ing my death for 20 years…keep going…I’m sure between now and when I turn 110 you’ll be onto something.”

But her weight is no laughing matter.

“She’s playing Russian roulette with her life,” warned Dr. Tabor. “She needs long-term counsel­ing and monitoring to fight her food addiction because time is running out