Kim Zolciak-Biermann is partying like it's 1996!

The mother of six is showing off her body on Instagram and she's as proud as ever, especially considering she's wearing clothes that she fit into in high school.

On Sunday, she showed off her curves on Instagram, while rocking a shimmering swimsuit.

"I feel the BEST I EVER HAVE!!!," she captioned the mirror selfie that showed off her whole body. "I wear the same size jean that I wore in high school 💃 and NO a tummy tuck doesn't make you skinny! 😡 so don't start... #310Nutrition #6KidsLater #4In30Months #Bye🙋."

Kim credited 310 shakes for her fit frame.

"THANK YOU @310nutrition my every morning drink!! I NEVER liked breakfast 😫 I know I know it's bad for you not to eat in the morning... Blah blah... Pregnant of course I did, after Kj in 2011, Kash in 2012, and twins Kane and Kaia in 2013 my body was use to eating breakfast😫 but I just couldn't do it!," shes wrote. "Sooooo that's when I found @310nutrition and it's been 2 yrs every morning I make my shake! I switch it up weekly as to flavor, fruit, almond milk, coconut water etc!"

Kim, of course, has often gone on the defensive about her body and her overall look, as many have accused her of plastic surgery. But the "Real Housewives of Atlanta" alum maintains that though she's had lip injections, she's never gone under the knife (to change her face, at least).

"I have not had surgery on my face period!!!!" she tweeted in June 2015 after a report surfaced alleging that she'd gotten a "full facelift."

Kim has previously fessed up to multiple breast augmentations and a tummy tuck after the birth of her twins.

"So it's been three weeks since I had my surgery, my boobs are perky, my stomach is super tight. It feels like I'm 20 again,'" gushed the reality TV star in a 2014 episode of "Don't Be Tardy."

"I look f------ amazing," she trumpeted at the time.

Earlier this year, she posted a video of bikini body to shut down haters who claim she edited her own photos.

No need to photoshop! Follow me on Snapchat KimZBiermann 😘😘

A video posted by Kim Zolciak-Biermann (@kimzolciakbiermann) on

"No need to photoshop!," she captioned the post.