The 26-year-old star has shed over 50lbs since appearing on US TV contest 'Dancing with the Stars' last year, but she hasn't enjoyed sticking to a strict diet and exercise regime.
She said: 't's been a lot of hard work, it hasn't been easy. Most of it's not fun but the results really are and it's just one of those things where if you stick to it long enough, and you work hard for it, then it can happen."
One of the biggest methods Kelly credits for her weight loss is eating smaller meals more frequently and she is confident anyone can follow her lead and lose weight.
Kelly ' who posed in a bikini for the new edition of Shape magazine ' added to gossip website Hollyscoop: "If it can happen for me, it can happen for you. No one ever thought that I would be in a bikini on a cover of a magazine. I never did.'
Kelly - who split from fiance Luke Worrall earlier this year ' recently admitted she had once been an emotional eater who binged on calorific snacks and only managed to change her ways thanks to the guidance of her 'Dancing with the Stars' partner Louis van Amstel.
She said: "I used to eat chips and cookies and drink soda all day long. I had to start making better choices.
"I indulge with pizza and cheese - I love Brie - and have cookies sometimes. But now, when I'm full I stop eating! It may have taken me 26 years to figure it out, but I've finally learned how to do it right.'
"Louis made me eat turkey burgers and salads. Then I started losing weight and realised, 'Oh, it's true what they say: Diet and exercise really work!' '