Kim Zolciak Unveils Skinny Bod 2 Weeks After Giving Birth to Son

She gave birth to her fourth child just two weeks ago, but Kim Zolciak is apparently bouncing right back.

The Real Housewives of Atlanta star, 34, welcomed son Kash Kade Biermann Aug. 15 with husband Kroy Biermann. But by Sept. 1, Zolciak's post-baby body was looking seriously svelte.

Her daughter Brielle, 15, Tweeted a gasp-inducing pic of her reality star mom in a long, tight black dress and quipped what everyone else was thinking.

"Seriously . . . who looks like this after 2 weeks of having a baby?"

No word yet on how Zolciak -- who's admitted to hating exercise on Real Housewives -- is dropping the pounds. Kash Kade joins big brother KJ Biermann, 15 months, plus Brielle and Ariana, 9, the Bravo star's daughters from a previous relationship.

VIDEO: See Kim without her wig!

Zolciak and Atlanta Falcons player Kroy, 26, wed in Nov. 11, 2011 in a wedding taped for their Bravo spinoff Don't Be Tardy for the Wedding.

Christina Aguilera: I Used to Be "Too Thin, Now "I Love Showing My Cleavage"

Christina Aguilera's fluctuating weight doesn't bother her as much as it seems to bother her critics.

Appearing on the October cover of Lucky, the Pennsylvania-raised Grammy Award winner opens up about her curvier shape, telling the magazine she's happy to show off her fuller figure in a myriad of tight outfits.

"The challenge I've always had is being too thin, so I love that now I have a booty," Aguilera explains. "And, obviously, I love showing my cleavage."

Though her shapely appearance has often been the subject of ridicule, Aguilera doesn't pay attention to the naysayers. "Hey, if you can work it and you can own it, that confidence is going to shine through," the blonde star says.

Christina Aguilera
Credit: Robert Erdmann for Lucky

Aguilera wasn't always so confident in her own skin. When her career was just taking off, the pop princess struggled to find her own voice. "When you're young, it's so easy to get bull­dozed," she says. "There were these two ladies who worked at the record label who always wanted to come to fittings and dress me up like a Barbie doll. It was disgusting."

Dating production assistant Matthew Rutler since late 2010, the Voice mentor (and mom to Max, 4, with ex-husband Jordan Bratman) is eager to share her new music with fans.

"If you love 'Fighter,' you're going to love my new album," she tells Lucky, referencing her triumphant hit single from her 2002 sophomore album, Stripped. "As a 31-year-old woman, I've been uncovering my independence, and it's been really fun to explore in the new songs."

Jillian Michaels: I Got "Chubby" After Becoming a Mom

She's inspired legions of overweight Americans to shed unwanted pounds thanks to her work on NBC's The Biggest Loser, but tough-as-nails trainer Jillian Michaels has waged her own battle of the bulge since becoming a mom.

Bringing adopted daughter Lukensia, 2, home from Haiti less than a week after her partner Heidi Rhoades gave birth to their son Phoenix in May, Michaels tells the October issue of Redbook magazine that she found herself carrying around a few extra pounds after her family expanded.

"I went to interview Suze Orman for The Insider, and her wife said, 'You're chubby! And Suze said, 'You look like a mommy now,'" Michaels -- who just inked a deal to return as a trainer on The Biggest Loser for this winter's season 14 -- recalls of her friends. "I look at my body and I go: 'five pounds heavier.' But part of me really likes it."

As she and Rhoades raise their son and daughter, Michaels tells Redbook she looks to voluptuous celebrities like Beyonce rather than stick-thin models to inspire a healthy body image in her kids. "We talk about role models for her, like Beyonce, who has a more curvaceous figure," says the trainer, who also appreciates the bootylicious singer's hot bod. "My taste has changed. I prefer that look. For now, I want to look a little softer."

Deciding to return to The Biggest Loser after a two-season hiatus, Michaels will work with the show's first-ever kid participants, ages 13-17, in a bid to raise awareness of the growing childhood obesity epidemic. "Having recently become a mother of two, I am more passionate than ever about helping empower children and families with the information and resources they need to live a healthier life," she has said.

Jessica Simpson: I'm "10 Pounds Away From My Pre-Baby Size"

Weigh to go, Jessica Simpson!

Four months after the Fashion Star mentor, 32, welcomed daughter Maxwell (with fiance Eric Johnson, 33), the Texas native is sharing the secrets of her success on Weight Watchers with the new issue of Us Weekly (on stands Friday), featuring stunning outtakes from a recent photo shoot.

"I'm 10 pounds away from my pre-baby size," says Simpson, who got up to 170 pounds while pregnant.

Sharing a typical day in her diet, Simpson says she wakes up at 7 a.m. to feed her little girl, then eats breakfast: half a Flatout flatbread sandwich with egg whites, peppers and fat-free cheddar (6 PointsPlus).

An hour later, Simpson straps on a pedometer and hits the streets with Johnson and Maxwell. "I'm trying to do at least 14,000 steps a day," the singer says. Simpson also exercises four times a week with pro trainer Harley Pasternak. In each 45-minute session, Simpson begins with a cardio warm-up, followed by circuit training that includes dumbbell triceps extensions, hamstring curls and crunches with a medicine ball throw.

"Her waist is going in, and her thighs are getting smaller," Pasternak tells Us of his A-list client.

Simpson -- who says she makes lunch "her biggest meal" to keep her full throughout the day -- will unveil her svelte figure in a series of Weight Watchers ads, debuting September 10.

Now that she's a mom, Simpson tells Us, "I believe I can do anything!"

Bikini-Clad Jennifer Lopez Flaunts Tight Abs, Swims With Casper Smart

Muy caliente!

Hours before she performed at the American Airlines Arena in Miami, Florida, September 1, Jennifer Lopez, 43, sneaked in some pool time at a local hotel with her twins, Max and Emme, 4, and her boyfriend of nearly a year, backup dancer Casper Smart, 25.

VIDEO: Half-naked Jennifer Lopez shows off her boxing skills

Wearing a black bikini that featured an asymmetrical strap around her right shoulder, Lopez showed off her enviable abs and world famous booty. The "Dance Again" singer also sported retro-inspired sunglasses, gold hoop earrings and a Hermes cuff.

Jennifer Lopez and her boyfriend Casper Smart go for a swim at their hotel in Miami.
Credit: WENN

After taking a dip with her twins, Lopez spent some quality time frolicking in the pool with Smart. At one point, the former American Idol judge wrapped her legs around the choreographer as he waded in the water and soaked up the sun.

Lopez recently turned to celebrity fitness guru Tracy Anderson to keep her in shape while touring with Enrique Iglesias. When the entertainer is pressed for time, "We skip dance cardio, since she's always rehearsing, and do legs and arms," Anderson told Us Weekly earlier this year.

During her trainer's rigorous workouts, Lopez depends on high-energy tunes to keep her motivated. "She's dedicated!" Anderson raved.