Dressed in sheer white lace, her underwear proudly – and deliberately – on display, it was clear Kim Kardashian was feeling her best And as the new mother unveiled the stunning results of her post-baby diet and exercise regime, it soon became clear just how happy she was to have lost her baby weight Actually I got on the scale today and it said that I am 50lbs down. That made me so excited, she said, as she made her big reveal on Jay Leno on Wednesday night.The 33-year-old said gaining weight while pregnant with daughter North was not easy ‘I can honestly say it was the greatest challenge of my life,’ she said And she confirmed reports she lost the weight on the Atkins Diet, adding ‘it worked for me Kim also revealed she chose the diet after it was previously successful when both she and her late father Rob tried it when she was a college student.Kim said the ‘ridiculous’ criticism she received for putting on the weight while pregnant wiwas incredibly painful It really hurt my soul,’ said the reality star. ‘It changed how I am in public. I’ve tried to live more of a private life The Keeping Up With The Kardashians star attributed her apparently bloated appearance during pregnancy to preeclampsia, a life-threatening condition that raises blood pressure, which she said led to her five-week premature delivery.That was a cause for a lot of the swelling and at the time I didn’t know what was going on,’ she said Kim showed off the impressive results – achieved by following the high-protein Atkins diet – in a daring lace dress She wore her blonde hair sleek and wavy over her shoulder and kept her makeup fresh and natural.Kim and new fiance Kanye West kept out of the public eye following the birth of their baby in June, but she denied they went into ‘hiding’ I just wanted to have time with her and be with her. This was the one time in life that I could just take off and spend time as a family with me, and him and the baby. So we both took a maternity leave,’ she said.But Kim said her life is going well at the moment after Kanye surprised her with a lavish marriage proposal on her 33rd birthday last week ‘I’m very happy right now,’ she said. ‘[The proposal] was the most magical night of my life And she described the night in detail.