But looking back, Alley, 58, is hardly shocked. During her three-year stint as a Jenny Craig spokeswoman, she famously trimmed down to 145 lbs. after losing and keeping off 75 lbs. But since parting ways with the company in 2007, she had not worked out and banished her gym equipment to the garage. As for her diet, her small, low-calorie portions gave way to Chinese takeout and pasta drenched with butter. "I fell off the horse," says the 5'8" star.
Today, Alley says she is primed to hire a trainer, toss the butter and sign up for a triathlon in order to whittle her "schlumpy" figure back down to a bikini-ready 140 lbs. "I'm going to have to work harder than last time," she says, but "I'm way excited." In a candid interview, Alley sat down with PEOPLE's Elizabeth Leonard to talk about how she piled on the pounds – and how she plans to get her body, confidence and – yes! – even her groove back.
Okay, how did this happen?
It started with New Year's , right after leaving Jenny Craig. When you're a spokesperson for Jenny Craig, there's responsibility. You have a person every week standing over you when you get on the scale, and I did it naked because those panties could weigh 30 lbs.! It was amazingly successful. But the first nail in the coffin was that I didn't have to weigh in. I just sort of went wild.
Did you go right back to indulging in cakes and pies the way you did the first time you let yourself go?
It wasn't the exact same M.O. My food demons are Chinese food, sugar, butter. A lot of butter. If I'm at the movies, usually I eat popcorn without butter, but I'd say, "I'm at the movies, so who cares?" And toast with butter. Or let's say I had two cups of pasta and six tablespoons of butter on it. There was a lot of butter going on.
What else would you eat?
For seven months I was a vegetarian, and I can't tell you how much weight I gained being a vegetarian! A vegetarian would probably be eating vegetables. But to me being a vegetarian meant I'm going to eat enchiladas with no meat, and I'm going to eat lots of bread, lots of carbs.
What weight do you want to get down to?
I have to be below 140 to really look good. I have to work my legs like crazy. Actually, do you want my real goal? My real goal's always too low. I love the way I look at, like, 128. One time on Cheers, I weighed about 148 lbs., and they told me to lose, like, 20 lbs. Now, I'm 5'8", so at 148 lbs., I wasn't fat. But they're saying, "You know, you need to lose 20 lbs." So what does that put me at? 128. That's where I keep getting this number.
Are you self-conscious?
I'm totally inhibited. When I'm overweight I will not go out. With my closest friends, yeah. But you wouldn't see me at a premiere.
But you seem ready to turn your life around.
I'm ready to work. I messed up along the way, but I'm not going to concentrate on that. I'm gonna go, "You know what? Get back on the horse, lose the freakin' weight, and then just move forward!"
For more on Kirstie's journey from slim to "schlumpy" – including her comments on her kids, her sex life and how she plans to lose the pounds – pick up the new issue of PEOPLE, on newsstands Friday
To keep up with Kirstie's journey, follow her on Twitter at Twitter.com/kirstiealley.