'When I'm staying at my place I'll wake up at 9am but when I'm at my mom's [Kris Jenner; also her business manager] she wakes everyone up at 7am. I like to try to work out early in the morning - I have a new trainer and it's so hard. I'll finish exercising around 10am, try to stop to get a tea - I don't drink coffee, I've never liked it - and I'll have some oatmeal when I get home. That pretty much fills me up for the first part of the day. After that I head straight to my store [Dash, in Calabasas, California]. My sisters Kourtney and Khloe and I run it; we all have different roles. My sisters are usually waiting for me because they live right next door, but I have to come from Beverly Hills and it takes me 30 minutes. Khloe runs the store on a daily basis, Kourtney does all of the billing and the three of us do all of the buying. Kourtney owns a store right next door, with my mum, called Smooch, so she's been in Calabasas a little bit longer and knows the customers and what we should buy, even if it's not to our personal taste. I stay in the back of the store and do the inventory and open up all the boxes we get. I get a lot of stuff delivered that other designers want me to look at or wear, which is amazing, but my sisters get irritated sometimes because all these boxes come for me and the shop isn't that big. We opened a year and a half ago and [Dash] is the first boutique that has designer stuff out in Calabasas. It's sort of country and, in the past, all the moms would drive to Beverly Hills to find fashionable things, but they don't have to anymore. The store has been doing so well and we're going to launch an online version soon, before the [Christmas] holidays. We have a lot of celebrity clients, which is really cool because they show everyone what they buy here. We make our buying trips fun too. My sisters and I always go to New York together; we find excuses to. When we're buying we try to make sure all three of us are there. We have a two-against-one system, if we don't all agree on an item we need two to say yes in order to purchase it for our store. If I'm on my own I can buy, and so can Khloe if she is alone, but Kourtney isn't allowed to - she has the funkiest taste, and every time she buys something we get really upset when it comes into the store a month later. It's all really fun because we get to see everything six months before it even comes out. We're ahead of the game. Sometimes I skip lunch, but there's a little restaurant right in between our stores that has the best healthy food, so I usually have a salad there. And we snack on cookies all day. My stepfather [1976 Olympic decathlon gold medallist] Bruce [Jenner] comes to the store either right before he picks up my little sisters [Kendall and Kylie] from school or right after to see if we need help fixing anything. He's the best handyman, he painted the whole store for us and construction-wise basically did the whole thing. If he comes after he picks my sisters up he'll bring them and we'll all have a snack together. We close the store at 6pm and go to my mom's for dinner. After dinner we'll help my little sisters with homework, or have friends over; there's always some drama going on in the house. My mom will fall asleep at 8pm with Kendall. She just passes out every night, probably because she's running back and forth so much. Everyone except my mom is usually awake until about 11pm or midnight. I go out all the time. I don't drink, so it's not like I'm going crazy and getting wasted every night. I like to go out to dress up, especially when I'm working. I've got photo shoots in the daytime now; I'll get my hair and make-up done and I can't go to bed, it's like I'm all made up. I have to go somewhere. It's what I do for fun, getting all my friends out. I'm working all day, so that's the only time I get to see them. I'm not a late-night party girl. I'll go somewhere and people will see me walking in and walking out, and that's it. I'm actually in early, but of course no one notices that. The clubs close at 2am, so I'm definitely home by 1am. You can go to the clubs and have fun and you don't have to drink, just like I can be a businesswoman and still be sexy. I can do both, why not? I've been modelling and doing a lot of endorsement deals back in the United States, and I have started acting a bit. But my dream would be to have a make-up campaign. Hugh Hefner invited me over to his house to ask me to do [a nude shoot for] Playboy. It was something I wasn't really comfortable with; I was kind of iffy about it then he told me all these fabulous people - Marilyn Monroe, Mariah Carey, Farah Fawcett - have been on the cover. He told me there's one lady, in her 70s now, who was one of the first to do it, and in her house there's a huge blown-up poster of her from when she was inside [Playboy]. She says it was the greatest thing - she did it 40 years ago and she can look back and see how amazing she looked. I figured I'm going to be married someday, and I'm going to have kids, and that's not something I want to do down the line, so why not do it now while I can. My life's exactly like it was before the television show [Keeping Up With the Kardashians; which premieres on Tuesday on the E! Entertainment channel] started. There are so many of us, so if someone was changing and acting different everyone else would be like, 'What are you doing, why are you acting so weird?' Even if we wanted to tone it down, we couldn't, because someone would mess up. People ask why I wanted to do a reality show. You're basically getting paid to stay at home with your family - anyone who wouldn't do that is crazy. We're just having fun with it, we have nothing to hide, and we're not scared that cameras are in the house, because there are so many different rumours and misconceptions about what Hollywood kids are like. This will show people who we really are then they can judge us after they see it.' To watch the interview with Kim Kardashian and see clips from the show, please visit www.scmp.com/multimedia .