Credit: Norman Scott/Startraks Photo: Kourtney Kardashian at Jet Nightclub in Las Vegas on February 20, 2010
Many women struggle to shed the pounds they gain while preggers — and some women never lose it. Lucky in more ways than just this one, Kourtney Kardashian is an exception.

The 5-foot-1 31-year-old packed on 40 pounds when she was pregnant with son Mason, who is now 11 months old. The more she grew, the more she couldn't wait to pop him out and get back to her old figure. "Kourtney is going crazy," Kourtney's younger sister Kim revealed to Usmagazine.com. "She feels so big right now. She’s just ready to have the baby."

Less than two months after giving birth to Mason on December 14, 2009, Kourt appeared on Jimmy Kimmel Live looking as svelte as ever. "Wow, I can't believe you just had a baby," Kimmel gushed. "You look fantastic. It's unbelievable how some people are able to just snap back into their previous shape." At the time of the early February taping of the show, Kourtney had lost a whopping 25 pounds of the 40 she'd gained. ("If I was a woman," Kimmel joked, "that would make me furious.")
Credit: Norman Scott/Startraks Photo: Kourtney Kardashian Heads out of Beso in Hollywood on November 6, 2010
In Hollywood, gaining and losing weight often looks effortless to us "civilians," but Kourtney literally worked her ass off. Her secrets? A seemingly obvious combination of diet and exercise. In a post-baby interview with Life & Style, she revealed she cut out the little things first, replacing things like fattening lattes with espresso shots. "I'm allowing myself one serving of caffeine while breastfeeding [baby Mason], and the latte was really all sugar and milk," said Kourtney, who also cut out juices and dehydrated fruits. "I was eating a lot of dried fruit, and I didn't realize how much sugar that added,” she added. "And now I'll eat raw almonds instead of salted ones."

She supplemented this healthier eating with exercises that added tone in all the right places — while maintaining the shape of her precious "booty." "I want to try to do squats — stuff that will keep the booty up there," she told the magazine. On top of that, she started jogging with her younger sis Khloé, and also made sure to change up her regimen every six to eight weeks.
Credit: BRJ/Fame Pictures Photo: Kourtney Kardashian Strolls on a Miami Beach on March 31, 2010
If this sounds easy and straightforward, it’s not. And in Kourtney's case, she took her new regimen a little too far. Her wake up call came when she passed out while running on the beach, having not eaten anything that day. "[I'd] been obsessing about this weight thing a little too much," she said. "I'm so embarrassed that I punished my body for a photo shoot." Kourtney learned her lesson, realizing that the key to any successful diet and exercise plan is about being slow and steady. She eventually lost an impressive 33 pounds in time to flaunt her post-baby body on an April cover of Life & Style.

"Definitely breastfeeding helps," Kourntey told Us. "Everyone says that, but it's really true — and it's just being a busy mom."

Sister Khloé added that she wishes she could drop weight as easily as her sister. "That's all it takes, breastfeeding?" she joked. "Then someone breastfeed off of me! I don't care!"

Sources: Fattyweightloss.com, Fitsugar.com, Thatsfit.com, NY Daily News