The star has teamed up with John Ratzenberger and George Wendt for her latest TV ad, in which she reprises her role as a bartender and serves up drinks to the two former Cheers regulars, as she shows off her 50-pound (22.7 kilogram) weight loss in a setting made to look exactly like the old bar from the series.

Kirstie, who became a spokesperson for the diet firm for the second time in 2014, admits she had her reservations about pulling off the ad, but she couldn't believe her eyes when she stepped onto the lookalike set for the shoot and had a blast with John and George.

"It was amazing," she tells U.S. breakfast show Today of the reunion. "When the Jenny Craig people asked me if I'd do it, I said, 'Well, yeah, I'll do it but is the set gonna look real?' They assured me it was gonna look fantastic and when we walked on that set, it was like a cross between The Twilight Zone and we were in a time machine! To see those guys sitting there, just as funny as ever... it was like we were right back in it."

The get-together was so much fun, Kirstie is keen to bring Cheers back to the small screen, especially as so many other old shows are being revived for new audiences.

She continues, "I thought, 'Why don't we just do this again?' It would be fun!"

Cheers, which also starred Ted Danson, Woody Harrelson, Kelsey Grammer, and Rhea Perlman, aired from 1982 to 1993.