Giuliana Rancic Bares Her Bikini Body, Is “On Top of the World”: Picture

On top of the world ????????

A photo posted by Giuliana Rancic (@giulianarancic) on May 27, 2015 at 3:30pm PDT

G's rockin' that bikini! Giuliana Rancic bared her bikini body via Instagram on Wednesday, May 27, showing off a healthier figure from behind in a skimpy swimsuit.

The E! News host, 40, is currently on vacation with her husband, Bill Rancic, and their 2-year-old son Duke in the luxurious destination of Cabo San Lucas, Mexico.

"On top of the world," Giuliana wrote on Instagram, alongside a photo of herself standing on the ledge of the pool with her hands on her hips, while gazing out at the endless turquoise waters surrounding her resort.

In the pic, the star shows off her perky booty in a pair of tiny tie-dye bikini bottoms. She looks significantly healthier and more defined in the snap, compared to her frail red carpet appearances this past awards season.

Let the games begin ????

A photo posted by Giuliana Rancic (@giulianarancic) on May 26, 2015 at 12:28pm PDT

The Fashion Police host also shared photos of her husband playing with their son in their infinity pool. "Let the games begin," Giuliana captioned a pic of Bill throwing a gleeful little Duke up in the air in the pool. She also shared a snap of her son and husband bonding at the edge of the pool while looking at the ocean below.

I can do this (forever) all week. #paradise #beyondperfect #nofilterneeded

A photo posted by Giuliana Rancic (@giulianarancic) on May 26, 2015 at 10:53am PDT

"I can do this (forever) all week," the Going Off Script author wrote. "#paradise #beyondperfect #nofilterneeded."

G's bikini body photo was shared after rumblings about her too-thin frame, which the show host addressed directly with Dr. Oz last month. "Trust me, I don't want to lose weight. I don't think it looks attractive," she noted on the program. "I think I used to be more attractive. But I'm doing the best I can… I'm just trying to get some more definition, because I want a little bit of curve, I want to be sexy. And right now, it's killing me to look in the mirror and see that I've just lost all [of it]. I'm just not the girl I used to be."

giuliana
Jim Spellman/WireImage

Oz spoke to Us Weekly days after her appearance to discuss Rancic's controversial physique. "She's on Tamoxifen because of the cancer and she will be on that for a while," the TV doctor noted to Us. "But it does cause you to lose some weight, plus she has a fast metabolism, plus she has scoliosis. All those things that make her look even thinner than she really is, but there's no question that she's too skinny."

Oz's advice for Rancic was to lay off the treadmill. "She needs to do yoga, Pilates, weights, strength-training. She needs to build up core muscle," he told Us. "That muscle will give you a little bit of a buffer. When you look at people who are really skinny, they are so frail that it risks their health. So she was actually bigger when she was diagnosed and I've done her show and I've talked to her many times. She needs to get back to that and she knows it."

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!