New mum Kim Kardashian was determined to show off the results of her post-baby slim down in a revealing swimsuit shot to silence her "nasty" weight-gain critics once and for all. The reality TV star came under attack during her pregnancy for piling on the pounds, but she has been hitting the gym since giving birth to daughter North in June (13) and has managed to shed 50 pounds (22.67 kilograms) by sticking to the Atkins diet, a low carbohydrate healthy eating plan. She put the results on show for all to see earlier this month (Oct13), when she shared a sexy photo of her famous curves in a white, halterneck one-piece on Instagram.com, and admits she wanted to rub her dieting success into detractors' faces after putting up with their rude comments and jabs. She says, "It really hurt my soul. It changed how I am in the public a little bit... There were these stories where I was, like, 200 pounds. I was gaining weight because I was pregnant and it was really hard to read all these stories and hear all these nasty things." But the Keeping Up with the Kardashians beauty made sure to ask her then-boyfriend Kanye West for permission to upload the image before getting her revenge online. During an appearance on The Tonight Show with Jay Leno on Wednesday night (30Oct13), Kardashian said: "I was trying on a bathing suit and I actually just sent that to my boyfriend and I was like, 'Babe, can I post this up? This is like my big middle finger to the world on everyone that called me fat.'" The socialite wore a see-through, white lace dress with black underwear to further show off her figure in her first big TV interview since becoming a mum. The couple has since become engaged after rapper West proposed to the mother of his baby girl on her 33rd birthday last week (21Oct13).