Kim Kardashian is oh-so-proud of her oh-so-svelte post-baby body -- and she doesn't want anyone to think she didn't work her famous booty off to get it.

The reality starlet is slamming a cover story in the tabloid Life & Style this week claiming that she underwent $80,000 in cosmetic procedures to drop the pounds she gained while pregnant with 5-month-old daughter North West.

"I am very frustrated today seeing reports that I got surgery to lose my baby weight! This is FALSE," Kardashian, 33, wrote on Twitter.

Lately, Kardashian has been showing off her hot bod in crop tops, see-through shirts, skintight skirts and, just this week, the video for fiance Kanye West's tune "Bound 2," in which she goes topless while straddling and smooching her man atop a motorcycle.

"I worked so hard to train myself to eat right & healthy, I work out so hard & this was such a challenge for me but I did it!!!" Kardashian tweeted. "I'm so proud of my accomplishment & NO ONE will take this away from me with fake reports! Say what u want about me but I work hard & am the most disciplined person u will ever meet!"

To get back in shape after welcoming her daughter, Kardashian has said that she went on the Atkins Diet and hit the gym. Last month, our spies saw Kardashian, along with West, sweating it out at a 6:30 a.m. class at Barry's Bootcamp in Sherman Oaks, Calif. According to one witness, the pair was "sweet and encouraging toward each other."