Kim Kardashian
Kim Kardashian shows off 50-pound weight loss. Tumblr

Kim Kardashian told talk-show host Jay Leno that she's 50-pounds lighter. The reality-TV star showed off her astounding weight loss on "The Tonight Show" Wednesday by wearing black underwear beneath a white Dolce & Gabbana lace dress.

“Actually I got on the scale today and it said that I am 50-pounds down. That made me so excited,” Kardashian told Leno. Getting rid of the extra pounds after the birth of her daughter North West in June “was the greatest challenge of my life,” said the curvaceous 33-year-old star who confirmed that she lost the weight by going on the Atkins diet.

Kardashian also opened up on Leno about how hard it was to be splashed on tabloid covers during her pregnancy. "It really hurt my soul," she said. "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. And I think people sometimes question, they think I'm out 'in hiding' now.

"No, I just wanted to kind of adjust my life a little bit because why would I subject myself to so much negativity, especially now that I have a daughter? I just didn't need that energy, I'd rather be in a happy place at home ... I've definitely tried to live more of a private life because of that, because they were so nasty. Why even go out as much just to put yourself in that position?"

Kardashian also talked about an Instagram selfie she posted earlier this month that created a media frenzy after she appeared in just a white bathing suit. "I was trying on a bathing suit and I actually just sent that to my boyfriend [Kanye West] 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.’”

After 18 months of dating, West proposed to Kardashian on her birthday Oct. 21 with a 15-carat Lorraine Swartz diamond ring.

Earlier this week on a Los Angeles radio show called “Big Boy’s Neighborhood,” West, 36, said the couple plans to wed “next summer."

"I only have two words in my mind as far as ideas for the wedding," he said. "That’s fighter jets.”