Kim Zolciak is getting smaller and smaller.

Kim Zolciak Credits Slim Post-Baby To Husband Kroy Biermann

Just over a year after welcoming twins Kaia and Kane, bringing her kid count to six, the former Real Housewives of Atlanta star is looking more trim than ever. In a photo posted to Instagram on Tuesday, Zolciak showed off her impressive weight loss.

"Werking......," Zolciak captioned the Instagram photo, in which she was seen in a gray T-shirt and jeans. Included in the caption of the photo were two cameras, which seemingly confirm Don't Be Tardy season four is currently in production.

Kim Zolciak Shares Waist-Trainer Photo On Instagram

In addition to twins Kaia and Kane, Zolciak, who married NFL star Kroy Biermann in 2011, is also mommy to sons Kroy Jagger and Kash Kade and daughters Brielle and Ariana.

After the birth of her twins, Zolciak began working out with Biermann, and drinking 310 Nutrition shakes, which she's mentioned a number of times on social media. Then, three weeks ago, Zolciak began waist training.

"Soooo you guys finally talked me into trying a waist trainer! I can't believe how tiny it makes my waist I'm obsessed with @nowaistclique waist trainer and it doesn't show through my clothes!" she wrote at the time.

She also encouraged fans to start working out their legs, and send her photos of their progress.

"Spring Break is almost here soooooo Pleeeze (I feel better when I know somebody else is doing it too). Do this 30 day challenge with me and let's watch our legs transform!" she said.

Don't Be Tardy's fourth season was confirmed earlier this month by AJC's Rodney Ho.