“When I meet young girls, I’m always like, ‘Just do me one favor,’ ” she tells PEOPLE in its new issue. “Love what you look like right now – and remember I said it 10 years from now because it’s the greatest gift I can give.”

Having already witnessed first-hand how tough it can be to love your own figure – the 31-year-old spoke out against critics in December 2007 when unflattering photos of her on the beach surfaced – Hewitt says she first focused on getting a mind makeover.

“I just really worked on my mental part for a couple of weeks, got myself in a really good mindset,” she says, adding that she was “bummed out” and “had to get over the embarrassment of the photos.

Then, the Ghost Whisperer star decided to give up her beloved donuts and make time to squeeze in workouts during her busy schedule – to get healthier, but not slim down drastically.

“I think I’m a work in progress,” she admits. “[But] I feel it’s so much better than [it was] a year-and-a-half ago, and I feel like in another eight months, it’s going to be so much better than it is today.”

Even with her new-found confidence, the 5-foot-2-inch Hewitt, whose Lifetime movie The Client List airs July 19, still fesses up to dreaming about having a certain body type.

“I’d want to have Gisele Bundchen’s body. Even though she’s tall and skinny, she does have curves … and I think that’s hot,” says Hewitt. “Halle Berry also is kind of amazing.”

For more on Jennifer Love Hewitt – including her diet tricks, exercise secrets and (honest!) thoughts on plastic surgery – pick up this week’s PEOPLE, on newsstands Friday

From People

Jennifer Love Hewitt may be rockin’ a bikini on our cover, but she has the same insecurities as every woman. “I’m a girl, after all!” says the 30-year-old actress. “For the most part, yeah, I’m happy with my body, but there are days when I’m like, ‘Ugh! Really? Why is it so hard to fit into my jeans?’ That’s when I say to myself, ‘I look this way because I’m supposed to. If we all looked the same, we’d be boring.’” Here, she reveals her stay-healthy-and-happy strategies as well as her work out that she uses to stay slim and confident.

Put your fridge on a diet To keep her food choices healthy and fresh, Jennifer hits the super-market every two days. “Instead of piling up food in my fridge that says ‘Come eat me!’ I keep enough for only a couple of days. And I rarely have treats around that might tempt me late at night, which is when I usually crave something really fattening. What am I going to do? Drive out at 11 at night just to satisfy a craving? No, that’s crazy.”

Always eat lunch It’s no secret that over the last few years, young actresses have become fixated on being super thin, a trend Jennifer finds really disturbing. “Hollywood used to revolve around women with curves, like Liz Taylor and Marilyn Monroe,” she says. “But now it’s so different. Not that long ago, I went to this celebrity luncheon, and I was the only person in the room eating. The other girls looked at me like I hadn’t gotten the memo, but I was hungry! All of these girls were afraid that if someone saw them eating, it would be a disaster. It makes no sense at all.”

Give yourself a good talking-to
Ever since turning 30 in February, Jennifer’s been practicing the art of positive thinking. At night she says five things she finds sexy about herself. “I fall asleep feeling beautiful,” she says. “Then, in the morning, before I leave the house, I say five things I love about myself, like ‘You have really pretty eyes.’ That way I can go out into the world with that little bit of extra confidence. It’s a feel-good protein shake in my back pocket in case someone messes with me that day.”

Don’t give in to peer pressure
One place you’ll never see Jennifer hanging out is in a Hollywood hot spot with other stars. “I’m not a big party person,” she says. “The idea of working all day then shoving myself into a club with 150 sweaty people who have been drinking sounds like the worst idea ever! At the end of the day, I’d rather just hang out by myself, with my boyfriend [Ghost Whisperer co-star Jamie Kennedy], or with my family.”

Put a spark in your workout
Jennifer’s been dating Jamie for seven months, and they’ve helped each other get fitter. “He’s inspired me to improve my diet,” she says. “He has a salad with every meal, plus lots of fruit, fish, and vegetables.” Jennifer, in turn, has gotten him to exercise more. “Last summer we were in Monaco. Every morning we ran for 40 minutes through the streets of Monte Carlo. It was an amazing way to see the city. Now when we travel, we try to explore the places by running.”

From Shape.com