With the latest size zero fad sweeping Hollywood, celebrities are under increasing pressure to look good and be slim. But not every celebrity is a natural-born size eight and we've hunted down their diet secrets.

• Minnie Driver
• Geri Halliwell
• Natalie Cassidy
• Lily Allen
• Claudia Schiffer
• Sophie Dahl
• Kelly Osbourne
• Gwyneth Paltrow

Minnie sheds pounds - and boyfriends

After years of yo-yo dieting for the big screen, piling on pounds for various roles and even dabbling with the Atkins Diet, Minnie Driver has found the one sure-fire way to lose weight - get dumped. Her recent heartbreak, losing her magician boyfriend Criss Angel to Cameron Diaz, has left the actress alone on the red carpet - and 10 pounds lighter.

Minnie had to out on twenty pounds for the `fatter friend' she played in Circle of Friends and lost pounds to play a drug addict in last year's US TV show The Riches. But are these roles to blame for Minnie's weight loss fluctuations - or is it her notoriously unlucky love life - Minnie says, 'When a woman puts on weight for a role she's called fat. It's so unfair. I was a bit lardy-arsed for a while, and then I was fit again.'

Geri hits the gym

Before recently Geri was proud of her curves, she said they enhanced her love life and claimed that diets weren't here thing. 'When I was skinny, my love life was like a desert, but the minute I got a few pounds on me, it all changed,' she once claimed.

But the Spice Girl who used to flaunt curves in her trademark Union Jack mini ten years ago is now Skinny Spice again and is back to the regimental dieting and hard-core workouts. The show is said to be an epic event with many costumes changes and Geri says, 'When you are on tour, there is nowhere to hide. You are singing and dancing in skimpy outfits and I want to feel comfortable in my body and have stamina.' Let's hope petit Geri still has some Girl Power left in her tiny body.

Natalie Cassidy

Soap star Natalie Cassidy has been almost unrecognisable since her transition from butch ex-Eastender to snake hips after her two-stone weight loss. These drastic results don't come from a crash diet or extreme fad. In fact, Cassidy didn't subscribe to any weight loss plan at all. She simply rustles up her own healthy meals from scratch - like soups - and pops down to the local gym to work out.

But she says now she's reached a healthy weight and doesn't want to go any further, 'I'm never going to be a stick because I've got big bones, but men don't like skinny birds anyway. I've never been on a diet. I think worrying about weight is ridiculous.'

So what's next for the new-look Natalie? You've guessed it - the obligatory exercise video is already in the making. The actress has recently been spotted filming at a dance studio.

Lily slims with hypnosis

Lily Allen always claimed she was proud of her size 12 to 14 figure making a bold statement in her ball gowns and trainers and famously criticising the size zero craze. Allen also fronted her own range for New Look with prom dresses for the curvier figure, when she said: 'All my dresses are super-girly but that doesn't mean you have to be a size zero. In fact, the more curves the better!'

She then made a comment on her blog saying, 'I'm afraid I have fallen victim to the evil machine. I have spent the past hour researching gastric bypass surgery and laser liposuction', before the singer who once championed curves jumped on the 'skinny bandwagon' and now says she is happier since plummeting to a size 8 to 10.

Allen didn't follow a conventional diet plan - she attended hypnosis session with Harley Street therapist Susan Hepburn to retrain her brain to crave healthy food and enjoy trips to the gym.

She says, 'After the hypnotism, I want to go to the gym every day, otherwise I feel really bad. I just want to get more toned and healthy. I'm really good about everything at the moment - I've never been happier.'

Claudia's model behaviour

Schiffer doesn't diet as she says 'it messes up your metabolism', but does have her own healthy eating regime. 'I keep my daily calorie count down by eating only fruit and vegetables before noon and quelling hunger pangs with healthy tomato juice, grapes and herbal teas.'

The model drinks also lots of water and takes regular exercise, like tennis and horse riding. 'It is about being comfortable with yourself and your body no matter what your shape or style - when you are happy on the inside your confidence shines through making you look and feel amazing' she says.

Sophie Dahl drinks green tea

Sophie Dahl's fuller figure was a national obsession in the 1990's, but since dating jazz musician, Jamie Cullum, there is more talk about Sophie Dahl's height than weight. The model is six foot tall compared to her 5 foot 6 inch beau.

Sophie was known as Britain's largest model and was proud to be an unconventional when she showed off her Monroesque figure in the infamous Opium adverts.

Now Sophie is slimmer than ever. She claims the old days were 'puppy fat' and that she wanted to lose weight to be able to swap clothes with her friends.

Dahl is said to have taken tips from London?s hip Body Doctor, David Marshall, to help her shed two stone, seven pounds and three dress sizes. Marshall encouraged Sophie to drink green tea to help flush the toxins from her body and it's said the regular brews helped her lose weight. She says, 'I slimmed from a size 16 to a 12 by sipping cups of green tea, which helps to speed up the metabolism.'

Kelly ditches biscuits and dances

Kelly Osbourne wowed audiences recently with her sexy and svelte transformation as Mama Morton in the musical Chicago - even if a little airbrushing was rumoured to help in the publicity shots.

Osbourne says that moving to London, without the US size food portions, and taking up dancing has helped her drop dress sizes and lose two and a half stone.

But it's not just the gruelling West End schedule and corseted look that have slimmed Ozzy's daughter. Kelly is rumoured to have ditched her favourite fix - Jammie Dodger biscuits. Her hair stylist Terry Longden says, 'There was never just one packet in her dressing room - they left a case. Nobody was allowed to touch them. We knew better than to come between her and her Jammie Dodgers. I pinched one and she chased me down the tour bus.'

Since breaking the biscuit habit, Kelly says weight loss has increased her pulling power, 'The good-looking boys only look at me now because I've lost so much weight - they would never have touched me before.'

Gwyneth stays organic

Since then she has resumed a healthier eating plan and she admits she's not as strict on herself as she once was: 'I'm not as stringent as I was in the past. I used to do a very strict macrobiotic diet, but then, during my pregnancy, I couldn't eat brown rice. It made me feel so sick. At first all I wanted were biscuits. Now I'll have cheese once in a while or white flour, but I still believe in whole grains and no sugar.'

Now, after the birth of her second child Moses (born in April 2006), Gwyneth sticks to an organic diet complemented with yoga and alternative health therapies. She says. 'I try not to eat any over-manufactured foods that aren't naturally welcome in my body. I try not to eat anything 'toxic' that will drain my energy.'