The Girls Aloud beauty admits she often can't always be bothered to exercise, because she finds keeping fit too boring.
She said: "I'm a bit rubbish. I'm like most girls in that I go in and out of phases for a couple of weeks. I think, 'Right, I'm going to go to the gym or do a DVD workout' for a few weeks but then I'll be rubbish for a few weeks and that's just the way it goes. I know a lot of my friends are the same. I'm out of the zone at the moment, but who knows – at some stage I might come back. I just struggle to make that a big priority in my life – it's a bit boring."
Although she doesn't enjoy exercise, Kimberley is constantly watching the calories because of her sweet tooth.
She explained: "I've always had to be aware of what I eat. If I just ate what I wanted I would be twice the size that I am. So I am aware of it, but again, I have good and bad days, good and bad weeks. If I'm being bad, I love sweet things like chocolate, ice cream, cakes – all the really bad stuff. But if it isn't really bad, it doesn't seem worth it! And when I stop myself, I just want it more, so I try to have everything in moderation.
"There is pressure to look good, but for some reason I seem to manage to put it to the back of my mind and not let it bother me too much. You just have to be happy and comfortable in yourself. I'm 28 now – I've been through all those times of feeling insecure and having those worries, and I'm not going to do that anymore. I don't care what anyone says."