But she admits it has not always been that way as she used to get called fat and ugly.
The 26-year-old was at one point more than 11 stone but the star lost three stone last year while on the US version of Britain's Strictly Come Dancing.
Kelly told British newspaper The Sun: 'I used to hate everything about myself, when you've been told your entire life that you are fat and ugly and that you are a spoiled brat, you start to play along with it and believe it.
'There will always be a side of me that doesn't like myself but Dancing with the Stars completely changed me - I managed to have a total life change and - so far - I've kept it up.'
She added: 'It's not like I look at myself and think I look amazing, I'm not that kind of girl.
'I'll always be able to find some self-deprecating comment to make about myself and how I look - but I don't hate myself any more, that in itself is good enough for me.'
Osbourne recently posed in a layer of gold paint to celebrate her new figure and mark the launch of Sky's 50th HD channel.
She said: 'It would have been like recreating Miss Piggy if they'd done this on me before, it is the most daring outfit I have ever worn.
'I did have a bikini on underneath but it felt really strange, like someone trying to suffocate me.'