Kim Kardashian insists she has worked "so hard" for her post pregnancy figure.

The Keeping Up with the Kardashians star has blasted rumors she digitally altered a recent photograph of her and her friend Blac Chyna to make them appear thinner before posting it on Instagram.

Addressing the allegations on Twitter for the first time on Friday, the 32-year-old star wrote, "It sucks when people make up surgery or Photoshop lies when I am so disciplined & work so hard! Just trying to motivate others & show anyone struggling with weight they can totally achieve whatever they want if they are dedicated!"

The reality TV star recently revealed she has lost more than 50 pounds since giving birth to her daughter, North West, in Los Angeles in June. Kim, who is engaged to rapper Kanye West, has been hitting the gym regularly and following the Atkins diet to slim down but recently revealed her New Year's resolution was to "get in better shape" in 2014. The blonde beauty, who suffered from the condition preeclampsia while pregnant, which caused her body to swell, previously admitted she craved "everything with cheese" when she was expecting North and gained weight everywhere.