Hollywood Hot Beach Bodies: Secrets to Their Success

It's summer, a time when some of Hollywood's top names head to the beach to reveal their toned, fit physiques.

In its June 25 issue, People magazine is naming this summer's hottest celebrity bodies.

"There's no shortage of fabulous, A-list women flaunting it in a bikini - and men, too, for that matter," Suzanne Zuckerman, senior writer for the magazine, said today on "Good Morning America."

As People celebrates these hot bodies of all ages, they also dug into the diet secrets to their success.

The magazine says pop star Rihanna, 24, traded in white rice for brown rice, and actress Paula Patton cut out bread.

"I mean, Hollywood stars have a great foundation when it comes to rocking a bikini, but a lot of them will honestly tell you they work really hard at it," Zuckerman said.

Some celebrities do it the old-fashioned way: slashing the calories. According to People, 34-year-old Maria Menounos' typical daily menu contains just 1,000 calories, while George Clooney's girlfriend, wrestler Stacy Keibler, 32, has about 1,200 calories a day.

And some of the hottest bodies on the beach belong to new mothers. After giving birth to her fourth child, supermodel Nikki Taylor, 37, lost 55 pounds by eating mostly vegetables, chicken and fish.

"Losing the weight is always a challenge for any modern mom," she said.

But it's not all about the ladies. Some of People's sizzling beach-ready bodies belong to men.

According to the magazine, newlywed actor Matthew McConaughey, 42, who stars as a stripper in the film "Magic Mike," prepared for his body-baring role by working out twice a day and eating only five protein-only meals a day. His co-star, Channing Tatum, 32, achieved less than 5 percent body fat by doing three hours of cardio a day and going dairy- and gluten-free.