Reality TV star Kim Kardashian West. (Picture: Instagram)

The 'Keeping Up With the Kardashians' star has managed to lose 20lbs (about 9kg) this year without running on a treadmill as she and her bodybuilder trainer spend 90 minutes a day lifting heavy weights. 

Speaking to E! News, the 37-year-old beauty said: "I work out about an hour-and-a-half every single day, heavy weights. I don't do a lot of cardio. But honestly, like even my mom pulled me aside maybe a week ago and pulls me in a closet and is like: 'What are you doing? I don't care what, I just need to know.' 

"I've been working out really hardcore with a bodybuilder for one year. September is our one-year anniversary. I've lost 20 pounds and I'm really proud of that. I was almost 140 forever and now I'm like 116 and it just feels good. I didn't see results right away, but when you stick with something and you're consistent, you will."

Kim's flawless body. (Picture: Instagram)

However, although she still likes to demolish a tub of Häagen-Dazs ice cream once in a while, she's tried hard to cut down on the amount of sugar she has. 

She explained: "I don't really eat sugar the way that I used to. It doesn't really do it for me. I've kind of been trained to just eat a lot healthier than I used to. I used to just eat anything and everything and I loved it. And so I really do control that now. ... I don't want to ruin it by just stuffing my face."

Kim went to her trainer Melissa Alcantara last year and told her exactly what she wanted her body to look like after training with her. 

Melissa said: "Kim told me: 'I love my body. I love the way it looks and I love my hips.' She just wanted more muscle. She wanted bigger hamstrings, which accentuates the entire leg. And she wants those cut arms and abs!"