EVERYONE'S talking about size zero - that teeny tiny UK size four which requires a waist size of just 22 inches and a calorie intake that would make most grown women weep.
Not so long ago, a size ten was considered thin - if your dress size was a miniscule eight you were scrawny. A size six? Well, you were probably a ballerina, or recovering from some terrible illness. That, or you were still a child. Now though, it seems that zero has become the aspirational size for all-too-many females. But what does it really feel like to survive on just 800 calories a day? We put Sarah Howden on the size zero diet for two weeks - with shocking results ...
THANKFULLY, I've always had a healthy attitude towards food. I'm definitely the type who lives to eat as opposed to eats to live. And as far as I'm concerned, life is too short to get hung up on body size. If I've piled on a few pounds, taking me above my average weight of 8 stone 7 lbs then I simply cut back and hit the gym.
But, I'll admit it, size zero can appear glamorous. Open any magazine or tabloid newspaper, or watch any TV programme and you'll be confronted with images of super-skinny stars wearing the latest designer outfit.
So what would it be like to live the size zero life? Instead of looking a bit dumpy - I'm only 5ft 2in - would I look glamorous and lithe in skinny jeans and pumps? Would I walk with a spring in my step and enjoy socialising more when my stomach's not bloated from enjoying a hearty meal?
The first challenge of my new regime turns out to be shopping for food. With a measly 800 calories to consume, instead of the 1800 calories a woman of my height and weight needs, I have limited choices available to me.
I resort to label-reading, scouring the back of produce to check that it keeps me within my daily allowance, and I walk away with porridge, diet tinned soups, salad, and a box of eggs. Hardly inspiring.
After a 100 calorie breakfast and two-mile walk to work, I'm ravenous, and it doesn't help when my colleague sits next to me munching his way through a double sausage roll.
Lunch in the canteen is also off the menu as everything is above my permitted 200 calories, so I make do with an unsatisfying tin of soup at my desk.
After that two-mile walk home I'm bad-tempered, shaky, light-headed and ravenous. But I have my weekly one-hour Bodypump weightlifting class to do before food-time - the only thing I can think about. Unsurprisingly, the class is a disaster. I shake as I hold the barbells and struggle to finish each set of lifting.
Back home, my piddly dinner is scoffed in seconds and I end up going to bed early, shattered.
Day two, things aren't any better. I start the day drooling at colleagues' breakfasts, and finish it stomping home to the insipid 400 calorie dinner awaiting me.
But on Wednesday there's a change. I wake up not hungry. My measly breakfast satisfies me, as does my pathetic lunch. The twice-daily walk is a breeze and I don't make dinner until much later in the evening because, again, I'm not that hungry. I even manage a one-hour gym session.
Thursday I'm on top of things, foregoing my dinner allowance for a couple of glasses of wine with my mates after work. They're shocked at my consumption - one slice of toast and some vegetarian sushi from Marks & Spencer - but they're even more shocked at my new-found unhealthy attitude towards food.
By the weekend my clothes are looser, my appetite has shrunk and the scales reveal I've lost five pounds. But I'm shattered. My mouth constantly feels dry despite guzzling litres of water, while my skin is dry and dull. No amount of moisturiser helps.
Socialising isn't fun either. At two house-warmings I went to, I wasn't able to relax. The sugary cocktails had my name all over them, but instead I had to stick to low-calorie wine. As people indulged, I had to abstain. As people partied, I sulked.
Sunday dinner at my parents' home is an endurance test. They tuck into a home roast, and I make do with a side-plate portion, with no trimmings. I struggle to muster the energy for my evening gym session, yet I find it hard to sleep. I spend the night tossing and turning, and wake up exhausted with a big fat headache.
That headache stays with me all through Monday. My hunger pangs are back, I can't concentrate and I'm in a foul mood. I scoff a calorie-laden burger in a two-fingered salute to size zero.
As soon as I've finish it something hits me - guilt. I have just consumed most of my daily allowance and it's only 1pm. I hate myself for it. I decide not to eat the rest of the day or the next morning to make up for my "greed."
It suddenly hits me how dangerous such a diet is. I am fighting my body's natural instincts, and all in a bid to be thin.
I don't sleep well and on Tuesday I'm a wreck. The previous night's Bodypump on an empty stomach nearly killed me and I woke shattered, ravenous and with awful skin - dry, patchy and spotty, and grey bags under my eyes. My headache is worse than ever. Desperate for motivation, I log on to one of the burgeoning number of pro-anorexia websites. It's shocking. Picture upon picture of emaciated girls with protruding rib-cages, hips and collar bones jutting out dominate them.
There are tips on how to fast or eat just 200 calories a day, hints on how to hide your eating disorder from family and friends, and exercises you can do to burn as many calories as possible. If hunger prevails they have countless "tricks" to ensure not an extra calorie is consumed.
It's alarming reading and I'm shocked to see how common extreme dieting really is.
By Wednesday I'm depressed, narky and tearful. I can't eat proper meals and give my body fuel, I can't function. I'm struggling to concentrate at work and muster up strength. All I can think about is food.
I'm beginning to give in to my urges, stuffing myself with what I'm craving, then punishing myself afterwards by going on a fast. Is this how these size zero celebs live? Is this why we see them tucking into junk food and dining out yet remaining stick thin? It's seriously unhealthy for both mind and body.
On Thursday I see my personal trainer Will. He's not impressed. Fitness tests with him in the past revealed my daily requirements are around 1800 calories. He's angry I've cut back so much.
My body has fallen into a negative nitrogen balance, he says. It's effectively eating itself, snacking on my fat but gorging on my muscle tissue.
All those toning sessions with him have been a waste - I'm rapidly losing muscle and gaining fat, despite losing pounds. I may be skinnier but I will be flabbier - didn't Victoria Beckham once admit to having this problem? - and my metabolism has slowed down too.
By Friday I've lost half a stone. That's seven whole pounds in less than two weeks. I should be delighted, but I don't care. I'm exhausted, I look awful and I can't be bothered with anything. All I want is my bed and my sanity back - after I've eaten everything in sight.
The size zero life is not for me. I can't comprehend how someone could choose to punish their body like this every day.
As I tuck into my first proper meal in nearly two weeks, I get a reply from a girl I contacted on one of the sites, asking for tips on dieting.
"Exchange a bad habit for a good one, so exchange eating for exercising," she says. And think higher of yourself! You're too good to put that s*** in your body."
Women have always had a bizarre relationship with food, and many of us view abstinence as a form of achievement rather than seeing food as an essential part of life. A skinny body was once a measurement of body shape success, now it's about being thin for thin's sake. Thin as a measurement of success, control, happiness - even if you're almost simultaneously on the verge of collapse. The size zero life is not for me - nor should it be for anyone.
WHAT THE EXPERTS SAY
Ruth McKean, a dietician with the Scottish Institute of Sport:
"Following a diet of such low calories over a prolonged period would increase the risk of cardiac problems, developing gallstones, hair loss, poor skin, and vitamin and mineral deficiencies, including anaemia. You may also become very lethargic and may feel dizzy due to low blood sugars.
"Menstrual cycles are likely to stop which could seriously affect future bone health. It's also likely to age you."
Will Sturgeon, a personal trainer of Willpower at the Balmoral Spa:
"If you followed this diet long-term you would come across all of the symptoms of an eating disorder.
And with every workout you'd be wasting your time.
"The whole idea is to tone and increase metabolism, but when your body is in a negative nitrogen balance it doesn't have enough fuel to replenish itself. All you would be doing is accelerating the detrimental effects and wearing down the muscle tissue as your body eats away at the muscle.
"You would go down dress sizes, but at a price. By your body eating its own muscle tissue you will lower your metabolism, put on weight quicker and, as you have lost muscle, you will be fatter."