Kim Kardashian does 100 squats every morning to stay trim.

The 'Keeping Up with the Kardashians' star, who gave birth to her first child, North West, in June, ''feels confident again'' after regaining her pre-pregnancy figure by following the Atkins diet and an intense exercise routine, devised by fitness guru Tracy Anderson, but still wants to lose more weight.

The 33-year-old beauty, who was criticised for the amount of weight she gained during her pregnancy, proudly showed off her body in a white bikini for the first time since welcoming her daughter into the world in the latest issue of Us Weekly magazine, and a source said: ''Kim feels confident again. She worked really hard and is motivated to stay fit.''

A friend of the star also told ''She wakes up and does more than 100 squats every single morning.

''Even now, when she can wear the things she did before her pregnancy, she still wants to tone her body.''

Kim, who got engaged to Kanye West in San Francisco in October, is currently travelling all over the U.S. with him for his Yeezus tour and has hired a personal chef to help her stick to her protein-rich diet.

A source told ''She's got a trainer on tour with she and Kanye and a chef to keep her meals carb free.

''With the exception of some cheat days, because she is realistic now, she sticks with it!''

Kim revealed in October than she had lost 50 pounds since she gave birth.