Fact. People look plumper through a camera lens. Fact. Designer clothes aren't, as a rule, made for girls on the sturdier side of life. But in the last few years female celebrities have taken weight loss to a whole new level.

Jessica Alba and Eva Longoria, long bandied about as refreshingly ‘curvy' Hollywood actresses, aren't curvy. They're very slim. Jessica Alba is a former anorexic. Even America Ferrera, the poster child for the ‘bigger' girl, isn't large. Queen Latifah is curvy.

Don't believe the woman that says the way she keeps her va-va-voom figure is by ‘walking the dog' or ‘running around after the baby.' My friends, that girl is a fibber.

Kate Moss eats what she likes, drinks up a storm, and would have been that way come hell, high water, or any number of cheeseburgers. Cameron Diaz is the same, although she now does have a workout regime, mostly through surfing and snowboarding. Gisele Bundchen was hassled at school for being tall and skinny. Sienna Miller is also miniscule, but that's the way these girls were built.

Let's face it, life is a gamble from the get-go and some people are just going to be dealt better cards than others when it comes to the body department.

Then there's the girls with the great figures who admit they work hard to get there, and more power to them. I've got absolutely no qualms about someone who gets a rocking body through their own sheer hard work (or the hard work of their plastic surgeon).

Jennifer Lopez has always been rigid about her workout routine, and has reportedly embarked on a fierce four hour a day fitness regime to shift her baby weight after the birth of twins in February.

Gwen Stefani admits that she's ‘super vain' and struggles to stay on a strict diet. Jennifer Aniston is a long time yoga devotee and dieter. Beyonce's awesome figure is down to more of the vegetable crudités than the chicken wings, and that's the sad but boring truth.

Who else has got a figure to die for? Penelope Cruz. Kate Winslet. Hayden Panettiere. Kate Hudson. Kylie Minogue. They're all slim (yes, I even consider Jennifer Lopez pretty trim despite her famous ass), and look healthy, happy and strong.

It's their job as acresses and celebrities to keep their bodies in top nick. If someone told me I must work out three hours a day and eat nothing but fish, chicken, veges and rice for six months of the year - but that I would get $10m for my trouble, you bet your curvy ass that I would be on that treadmill quicker than you could say 'macaroni cheese.'

But when does super slim make the slippery decline into skinny?

Especially with small women the difference between slim and skeletal can be a few pounds, easily gained and lost either way. But some female celebrities have taken weight loss to a whole new extreme, and not necessarily a good one.

Nicole Richie was the frontrunner of this trend a few years ago, rapidly losing weight after she found fame in The Simple Life with Paris Hilton. Paparazzi pictures of Nicole's tiny neck supporting a huge head, twig-like wrists holding giant coffee cups circulated for years.

One particular shot of Nicole running along a Malibu beach with her bikini sagging off her body, sinewy legs and a protruding ribcage drew gasps of horror from even the most jaded of celebrity observers.

She was so thin that when Richie got pregnant with daughter Harlow last year, nobody believed she'd even still have a period to conceive. But Nicole's a mama now, and along with a bouncing baby daughter she also boasts a petite, but healthy looking body with an added bonus, a voluptuous pair of boobs.

Renee Zellweger, who stacked on weight to play literary heroine Bridget Jones in two films, is so thin it actually looks like it hurts to be her when I see her in photos. She's all tendons and sharp shoulderblades. She is renowned for a strict diet and exercise plan, and my prime suspect for the rumour that went round a few years ago about the actress working on Cold Mountain who ate nothing but two boiled eggs a day for three months.

That, one could argue, looks like far more than Victoria Beckham would eat. Posh Spice is so thin she probably thinks Renee Zellweger is a fatass of the highest order. Victoria's mantra is reportedly ‘If I'm thin, I'm in' and she has adopted it with gusto over the last decade - and despite giving birth to three kids. At her smallest, she was said to have the same waist circumference as a seven-year-old child - but still boasts those stupendously oversized boobs.

Her appetite, or lack of it, is legendary. Although Victoria likes a tipple, sustenance of a solid doesn't seem to often pass those lips. She is said to survive only on tomato soup, endamame beans and a couple of cooked prawns.

Word has it that Posh and her new pal Katie Holmes recently had dinner at a Beverly Hills restaurant. They ordered one meal to split between them, which consisted of one piece of steamed fish, spinach, and salad without dressing. They shared one Coke, mixed with bottled water.

Paris Hilton was spotted recently, the Daily Mail reports, seated at New York restaurant Nobu. Over the course of two hours, while her companions ate around her, Paris did nothing but sip water and Red Bull.

Her scarily skinny sister Nicky claims her recent dramatic weight loss is down to swapping white bread for wholemeal.

It looks like it pains Kate Bosworth to walk, let alone attempt anything more strenuous. She's all pointy elbows and bulgy knees and visible ribs. And twiglet legs. She looks frail, and she looks weak.

Angelina Jolie got scarily skinny there for a while, but around the Lara Croft-era she has one of Hollywood's best bodies.

Eva Longoria is very slim, no doubt about that, but she's one of the only size zeros in Hollywood that looks healthy for it. Nicole Kidman is very thin, but it looks natural and it suits her.

It comes down to this: does being skinny necessarily mean you've got a great body? I say no. I wouldn't want a figure like Amy Winehouse, or Mary-Kate Olsen.

I couldn't live on alfalfa sprouts and soy beans. I crave brownies and carrot cake and corn chips with guacamole. Cold beers and blue cheese and peanut butter and pizza. Not all at once, trust, but they all make an appearance every now and then.

The hot body I hear my girlfriends talking about coveting at the moment is not Kate Bosworth's but Kim Kardashian's. Girl's got a great ass, is a knockout when she's out and about, and claims to eat a diet of ice cream, chicken strips, and deep fried Oreo cookies.

How thin is too thin for you on a woman or a man, for that matter? When does skinny cross that line into scary? And which celebs have taken weight loss to scary extremes?