Osmond is working on an "inspirational album;" Bertinelli has plans for an exercise DVD. Both say they're considering doing talk shows.
But isn't it easier to lose weight when you're being paid to do it? Bertinelli said no.
"I'm paid to be a spokesperson and do commercials," she said. "And 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."
The fear of public humiliation may also have something to do with it. People magazine "Body Watch" editor Galina Espinoza said the celeb diet wars have never been more heated.
"I think it's really interesting that something that wasn't quite possible 10 years ago -- a celebrity endorsing a diet product? That would have been career suicide I think a decade or two ago -- today it is considered a way to catapult your way back into the spotlight," Espinoza said.
Espinoza said a fundamental part of her job is keeping track of the ups and downs of celebrity weight.
"Just think about flipping through a magazine with your friends, and you say, 'Oh, what did Kate Hudson do to her hair,' or, 'Oh, Scarlett Johansson looks like she may be putting on a few pounds.' This is what we talk about," she said. "This is part of the public conversation. "
But the intense media scrutiny can trip up some weight loss success stories.
Former Cheers star Kirstie Alley lost 75 pounds on Jenny Craig, but has gained it all back, plus 10 extra pounds. Bertinelli said Alley was her weight-loss mentor and denied that there was ever a rivalry between the two.
"There never was," she said. "Not at all. Ever. She opened her arms and let me in and gave me all of the greatest advice. And I miss her, I miss her.
"She is a very big part of why I am here. 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, and I was like, no, I just want to get into a smaller size. And she was right."
Alley, who left Jenny Craig in Dec. 2007 shortly after debuting her bikini-ready body on "The Oprah Winfrey Show," recently confessed her weight gain sins to Winfrey. She now plans to open her own weight loss program, but Bertinelli is hoping she'll come back to Jenny Craig.
"Let me mentor you this time," she said. "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."