"I'm always going to have a curvy Italian figure, but it's a little too much now," Bertinelli says of her current size. Photo by: STEPHEN DANELIAN
Valerie Bertinelli: Ready To Get Slim! | Valerie Bertinelli
"Empty!" shouts Wolfgang Van Halen, shaking a large box of Corn Pops cereal at his mom, actress Valerie Bertinelli. "Every single piece of food in the house is Jenny Craig," laments the high school sophomore and guitarist, surveying the airy kitchen in the family's Studio City, Calif., home, which is now brimming with prepackaged food from the weight-loss program. And Wolfie – the 16-year-old son of Bertinelli and her ex, Hall of Fame rocker Eddie Van Halen – is having some issues with the controlled portions. "You open a bag of [Jenny Craig cheese curls] and there's, like, three in there." Evidently he's not the only one feeling the pinch. Bertinelli's boyfriend of nearly three years, Tom Vitale, "hit our Doritos last night and ate like 14 bags!" reveals Wolfie, laughing. Then, looking over at his bemused mom – who lost 10 lbs. in her first three weeks on the diet – he shrugs. "Well, it is working," he says. "So maybe it's for the best."

Cheese-curl rations and all, Bertinelli, who turns 47 this month, has no complaints. Joining Kirstie Alley as a celebrity face – and body – for Jenny Craig, the 5'2" actress best known for her 1975-84 sitcom One Day at a Time is vowing to lose 30 lbs. by September (from a size 14 to a size 8). Going public with her goal "is the motivation I need," she says. "I need to do this in front of millions of people so I can't mess up. It is freeing because I can say it first: I know what you're thinking – I'm fat."

"We feel the same way about weight loss," says Alley, 56, who has maintained her 75-lb. downsizing. "She isn't interested in promoting whittling yourself down to a size 0, and I agree." Bertinelli says Alley also offered some advice: "She said, 'Even if Wolfie wants to go to In-N-Out Burger, don't do it, because paparazzi will photograph you!' "

The campaign, for which she will shoot a new ad every month as she shrinks, represents a major step back into the public eye for Bertinelli, lately a stay-at-home mom whose last big TV role was on Touched by an Angel in 2003. "Wolf is my priority," she says. "I was a Hollywood hermit." Also, she adds, "I didn't like going up for interviews because I didn't want to hear how fat I am."