Kim Zolciak recently debuted a much bigger behind than fans have seen in the past.

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Although the former Real Housewives of Atlanta star has yet to confirm any plastic sugery on her backside, a top plastic surgeon has weighed in on her new body, claiming she may have had some sort of work done in recent months.

"It is definitely possible that Kim Zolciak has had her buttocks enhanced," Tony Youn, M.D. told Radar Online on May 26. "This is done my liposucting fat from the hips or thighs and then re-injecting it into the buttocks."

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While Zolciak's butt appears to be flat and nearly nonexistent in photos from years ago, she is suddenly giving the Kardashians a run for their money. On Instagram, Zolciak frequently shows off her new figure, and her latest backside photo caused quite a stir.

"Another option, but much less popular, is placement of the buttock implants, but I suspect if Kim has had her buttocks enhanced, which it looks like, she underwent fat injections into her buttocks," Dr. Youn continued.

In the past, Zolciak has admitted to having surgeries, including a breast augmentation and tummy tuck. However, when it comes to her face and the rest of her body, Zolciak claims to be all natural.

Zolciak will return to Bravo later this year in Don't Be Tardy season four, as well as her new spinoff with NeNe Leakes, The Road To Riches.