Celebrity yo-yo dieters

Khloe Kardashian

Twenty-seven-year-old Khloe has publicly admitted to having struggled with her weight for most of her adult life, and the reality TV star says that having such tiny sisters doesn't help the way she looks either.

"They are 5ft and 5ft 2, so I look massive next to them," says the 5ft 10 star. "Everyone expects me to be 9ft tall and weigh 200lbs [when they meet me]." Adding that she's an emotional eater, and that following her parent's divorce, "they gave us food to keep us comforted. All we did was eat ****. I had older women tell me, ‘You should really work out'. It really got to me." Married to 6ft 10 basketball player, Lamar Odom for three years, Khloe says that although "people have called me ‘fat' and ‘different' my whole life" that "Lamar makes me feel like I am the most beautiful woman in the world and that is all that matters to me."

Abbie Cornish

The stunning 29-year-old actress stepped out for the opening of Marquee nightclub in Sydney last week looking noticeably curvier than she was when she last appeared on film in Madonna's W.E. And the Australian star, who got her big break starring opposite Heath Ledger in 2006's Candy, has revealed that her weight fluctuates a lot - and that she couldn't care less!

"I'm pretty unusual for an actress in Hollywood because I am totally unselfconscious about my body," she says. "I've never been in better shape than when I did Sucker Punch because we had to fight and dance and wear incredibly tiny outfits. I lost a tonne of weight when I was a junkie in Candy… I was incredibly thin." Adding, "Now I'm a lot more curvy because I'm eating what I want. I like to watch my body go up and down in size for the roles that I play; it's interesting and I have absolutely no worries about taking my clothes off for love scenes. It doesn't faze me at all."

Jack Osbourne

The new dad to baby daughter, Pearl, has watched his weight creep back up after he dropped 50lbs (23 kilos) in 2006 with the help of a martial arts-based regime. The 26-year-old appears to have relaxed his diet too, after he was spotted hitting an Italian spot for lunch before eating ice cream in an LA park with fiancée Lisa Stelly, recently.

Calling the first week of his weight-loss detox "one of the most miserable weeks of my life", Jack weighed 16st 5lbs (104kg) at his heaviest, but never quite achieved his goal weight of 10st 5lbs (66kg). And after his TV show, Jack Osbourne Adrenaline Junkie ended, and the reality TV star vowed, "For as long as I live, I will never allow a camera in my house again," it looks like Jack no longer has anyone to stay slim for.

Cheryl Cole

The gorgeous Girls Aloud singer has seen her weight go up and down according to her emotional state, with the star having faced a tumultuous past couple of years thanks to her sacking from The X Factor USA and the breakdown of her marriage. And the 28-year-old admits, "I'm like any other woman, my weight fluctuates. I have a pair of jeans one size bigger than the other just in case that week I'm a little bit heavier." Adding, "I work out and try to make healthy choices." With her weight famously plummeting in the wake of ex-husband, Ashley Cole's affairs, and again when she contracted life-threatening malaria, the singer and reality TV judge recently showed she had embraced her new curves during a recent trip to the BBC Radio 1 studios and admitted, "I avoid diets like the plague."

Jonah Hill

He dropped an impressive 40lbs (18kg) after finishing work on the Oscar-nominated Moneyball alongside Brad Pitt - and insiders say it was Brad who encouraged Jonah to get into shape - but whilst promoting his latest movie, 21 Jump Street, it looks like Jonah's slipping back into his bad old eating habits. Having revealed the secret to his weight loss as being down to "mostly diet". Adding, "I went to see a nutritionist, and he told me what to eat to change my habits and stuff. I found that Japanese food was very helpful to me," the 28-year-old rubbished rumours that he had re-gained the weight he lost because he was struggling to land roles as a slimmer actor and instead blamed it on alcohol. "I still drink beer - that's my Achilles' heel I think," he admitted. "It's so annoying because if I don't drink beer I get really thin, and then when I drink beer I get a little bigger."