"If you want to change your body, you can't just diet," explains Kelly. "If you do that, you lose weight, then get fat. You've got to commit to a whole life change and teach yourself a whole new lifestyle. … It isn't fun, but it never will be. I don't deny myself anything -- I still eat chocolate and cake and always will. Everything in moderation."
Osbourne, 28, readily admits "working out is not fun. I'm not going to lie and say it is. I sweat my arse off, and I'm miserable for the hour I'm doing it, but when I'm done, I feel amazing. There's no quick fix, and it does take a long time. It drives you mad when you see someone eating chips when you can't have any, but it's so worth it."
She cites a feeling of accomplishment for pushing her forward.
"When I started exercising, I couldn't even do one sit-up!" marvels the lavender-tressed "Fashion Police" host. "By the end of the first week, I could do three, and that was a big deal. Now I work out every day, and I just don't feel good if I miss it. It's amazing how quickly your fitness builds, but you have to really want it."
In addition to gushing about her boyfriend, vegan chef Matthew Mosshart ("I have finally learned to let somebody love and treat me the way I deserve to be, and that's a great feeling"), Kelly reveals the moment when her mind and body makeover really hit home.
Click on to find out when she had her epiphany ...