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Valerie Bertinelli wants to help her former Jenny Craig colleague Kirstie Alley, who recently admitted she gained all her weight back (plus 10 extra pounds).

"Let me mentor you this time," Bertinelli, 49, says Wednesday in an interview with ABC's Nightline. "I'll hold her hand. Oh, I would just - I'm telling you - I think it would be the greatest thing. There's so many people that come up to me wherever I am, and they say I was on the program a couple of years ago, and then I stopped, and then I see that you've had success, so I'm coming back. It's not a bad thing to stop something and come back to it. You're not a failure. You're never a failure. As long as you keep getting back up."

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Alley, a former Jenny Craig spokeswoman, introduced Bertinelli to the program, serving as her weight-loss mentor. When Alley left the program, Bertinelli become the new face for the company in March 2007.

The star - who lost 49 pounds on Jenny Craig - says "there never was" a rivalry between them.

"Not at all. Ever," Bertinelli says. "She opened her arms and let me in and gave me all of the greatest advice. And I miss her, I miss her."

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"She is a very big part of why I am here," Bertinelli goes on. "She said, 'This is going to be a lot more about losing weight, this is about finding out who you are and what you're made of.' I was like, 'No, I just want to get into a smaller size.' And she was right."

Bertinelli says women can relate to overweight stars because of their real-life heartaches and struggles.

"I look like your next-door neighbor," she says. "I mean, half of this country is divorced. Half of this country has been married. So I've been through everything that everyone else has been through."

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In her 2008 book Losing It, Bertinelli opened up about her past life experiences, including locking lips with another woman when she was in her 20s. ("It was not a lesbian fling," she insists. "It was a kiss.")

Says the star, "I don't ever feel like I've been particularly wholesome, just relatable. You know, and no one really is wholesome. I'm a bit of a prude. ... I think it's probably because of all of the stuff I did in my 20s. Now I'm, you know, rebelling against my 20s."

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Bertinelli -- who also battled cocaine abuse and a messy split with husband, rocker Eddie Van Halen -- says her personal dramas fueled her lifelong addiction to food.

"That's my drug," she said. "That's why I'm still not using coke. I mean, I could still be on coke right now, but that wasn't my love. Food is my love. I was getting bigger and bigger the tougher it got. I was feeding my fears and calming my emotions ... through food. And it showed."

One day, Bertinelli says, she got a phone call from Jenny Craig.

Her first thought was, "Oh God, they know I'm fat too! How do they know?"

"My life felt out of control," she says. "At that point, you are just looking for a life raft, a life preserver, somebody help me, and they were there."

According to Jenny Craig, 150,000 people sign up each week, inspired, over the years, by the likes of Bertinelli.

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She says she now has plans for an exercise DVD and is toying with doing a talk show.

She insists it isn't easier to lose weight when you're being paid to do it.

Says Bertinelli, "My job is to lose the weight for me, because you can't do it for anybody else. And nobody can do it for you."