Kim Kardashian West claims her unborn son is the same weight as a
Kim Kardashian West claims her unborn son is the same weight as a "really heavy pineapple".

Kim Kardashian West vows to drop 30kg after birth of son

KIM Kardashian is "so focused" about losing her baby weight.

The 35-year-old reality television star welcomed son Saint, her second child with husband Kanye West, into the world last December.

Now, just seven weeks later, Kim told her fans on Twitter that she has already achieved an incredibly impressive weight goal.

She tweeted: "I'm so excited! I'm 30 lbs down today but 40 to go! I'm so focused. I will show u guys my workouts on my app & share my Atkins plan too (sic)!

"I gained 60lbs (27kg) during my pregnancy but have been an extra 10 lbs up for the last few years so it's time to really get to my goal. This is going to be soooo f**king hard but I can do it and I can't wait to share it all with you! #BeastMode #WhosWithMe ?!?!?!"

It was previously claimed that Kim was planning to throw herself into her diet and exercise plan after welcoming baby Saint, because she wants to look better than ever.

A source told "Kim has huge goals this time, she's even more motivated than she was after she had North. As soon as she gets the all clear from her doctor to work out, she's going to have her trainer coming to the house 5 days a week. And on days when she isn't working with her trainer she'll still be doing cardio. She wants to lose this weight as fast as humanly possible."