“I’m obsessed with Have Faith swimsuits,” she said on Feb. 20 in a Instagram photo caption.
In August, Zolciak, 34, and her NFL husband, Kroy Biermann, 26, welcomed their fourth child, Kash Kade.
This isn't the first time she has shown off her slimmed-down physique after giving birth to Kash.
Zolciak was featured in the January issue of Life & Style magazine, where she said, “I’ve lost 30 pounds. I’m only 5 to 8 pounds above my weight before I got pregnant.”
When asked how she reached her weight loss goal, she said, “I never sit on the couch.”
“I think breast-feeding helped me lose some weight, and I was really busy as soon as I got home with Kash. I went straight into filming my spinoff show, ‘Don’t Be Tardy,’ and I’m sure that helped. I just never sat still!”
Zolciak added that she watches what she eats. “I don’t eat red meat or pork or much dairy, and I always eat in moderation. I’m a size 4 right now, and my goal is to get down to a size 2.
"I’m accepting that I’m going to have to hit the gym — my girls [Brielle, 15, and Arianna, 11] laugh and say there’s no chance, but I really think I’m going to have to.”
Some Twitter followers criticized her for posting the photo.
“Way too old for this. I feel sorry for all her kids,” one user wrote.