Kim Kardashian and Kanye West welcomed their son Saint just three months ago, and the mother of two is already on a fast-track to getting her body and incredible curves back.

The 35-year-old reality star has been very open about her weight loss journey since she gave birth to her second child and has been on the Atkins diet ever since. Her goal is to lose 70 pounds, and considering she's already lost 42 pounds in just three months, the diet is obviously working for her. Since the plan worked so well after she gave birth to North, she knew that it was something she had to stick to in order to reach her goal.

"[Kim] was originally introduced to the Atkins diet by her father when she was in college," said Colette Heimowitz, her nutritionist. "It was very familiar to her and she trusts the plan because it worked so well for her in the past."

Heimowitz went on to explain that Kardashian has protein in every single meal, whether that be eggs, fish, chicken or meat, and that she pairs that with high-fiber foods and healthy fats. While her sister Khloe notoriously stopped eating dairy to lose the incredible amount of weight she's lost over the past several months, Mrs. West just couldn't do that.

"[Kim] is limited to four ounces of cheese a day," Heimowitz said, adding that things like sour cream, half-and-half and butter are not included in that. "These things aren't unlimited but she can have them-just enough to keep you satisfied. [Because] a tab of butter on broccoli is way better than just boiled broccoli."

As for her calorie intake, she's been eating 1,800 calories a day, which may seem high to some but since she's pairing that with a low-carb, no-sugar diet, and it works. "[No] sugar, sweets, cakes, crackers, white flour, white rice," Heimowitz said of her restrictions. "[So] instead of white rice you have a little brown rice. Instead of a white potato you could have a yam. And [when you want] dessert, you can make one with Splenda instead of sugar."

Kardashian also took to her website earlier this week to reveal how she stays motivated while trying to lose weight, and to no surprise, the selfie queen says that she looks at old photos of herself to keep her on track.

"I look back on photos that kind of inspire me. I did it then, I can do it now," she said in the video. "I have to be patient. It just kind of shows you, you can do it, it will just take time, stay focused, and don't let anything get you off track."