It took her just seven months to get back in perfect shape, so that Kim K is the envy of new mothers out there working to lose postpartum weight. E!News reports that in an Instagram post, the most famous Kardashian revealed a toned stomach and butt, shaming her detractors who had been critical of her weight, especially during her pregnancy.

The Keeping Up with the Kardashians star posed with her gym buddy Blac Chyna, who is the girlfriend of rapper Tyga. In the photos, both girls show off their fabulous figures, with the Reality TV starlet wearing an all-black ensemble consisting of a pair of black sports bra and tight leggings, while friend Blac Chyna wore a gray midriff top paired with tight-fitting gray sweats. . The brunette hottie captioned the photo, "getting right for the new year."

This Instagram post is quite similar to an unpopular snap that the 33-year-old starlet had also published online back in October, when she took a selfie that revealed her famous derriere while donning a skimpy white swimsuit. Within minutes of the post, Kim K had received quite a backlash from netizens who criticized her for behaving inappropriately as a new mother to daughter North West, according to the Daily Mail. While the post didn't sit well with some social media users, Kanye West had been delighted with the snap as he re-tweeted the photo with a sexy quip saying, "heading home now," according to Huff Post Celebrity.

Kim has credited the Atkins diet for her weight loss results, and says she loves the program. The Atkins Diet follows a low-carbohydrate formula for weight loss. In their website, Atkins International lists four phases of the diet. Developed by Dr. Robert Atkins, the program discourages the inclusion of carbs in meals, but also encourages dieters to enjoy food by not being overly-obsessed with counting calories. According to her rep, Kim has been "eating lots of lean proteins, healthy fats like nuts and avocado, carbs, fruits, veggies and cheese. She wanted to be a healthy, nursing mom and not toxify her milk with her diet or lose weight too quickly. She's been doing Atkins since her doctor approved it at the end of June," reports The Hollywood Gossip.