Kim Kardashian West is "focused" on losing weight, after revealing she has put on 18 pounds (about 8kg). Picture: AP

Kim Kardashian West is "focused" on losing weight, after revealing she has put on 18 pounds (about 8kg).

The 'Keeping Up With The Kardashians' star recently claimed she has gained weight, and is now believed to be hitting the gym ahead of the festive season in order to get back to her goal weight before the holidays, as both Thanksgiving - which will be celebrated in America on November 28 - and Christmas are both holidays that often involve a lot of indulgent food.

A source told Us Weekly magazine: "Kim is really focused on getting back to her goal weight and to a place where she feels totally fit and comfortable with her body.

"The 18 additional pounds that she has gained have made her feel less comfortable in clothing and has made it harder for her to find pieces she's excited about wearing.

"She has been working out very diligently, so she can feel like 'herself' again and wear the items she wants to without worrying about how they will fit."

Kim, 39, spoke about her weight gain earlier this month.

Posting on her Instagram story, she wrote: "OK, so we're doing a night workout before my dinner, which I never do with this one [Alcantara], but I figured we have to get into it at some point. And yeah, I mean, sometimes we fall off and sometimes you really gotta get it together and this is one of my fallen off times where I am, I think, 18 pounds up from what I was about a year ago, a year and a half ago. 

"To feel good, I just want to get it like, a really good goal weight and so that means working out at all costs. It's my eating. I work out but it's like, my eating. But Melissa and I have a major goal for by the time I'm 40."

The beauty - who has North, six, Saint, three, Chicago, 21 months, and Psalm, six months, with her husband Kanye West - previously confessed her soul was "broken" by bodyshamers.

Speaking about her pregnancy, she said: "It changed my body, my skin. All I have to do is type Kim and Shamu. It really changed my security. It broke my soul for a while ... 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."