SIZE zero maybe the ultimate celebrity quest but the reality of living with a superskinny body is far from glamorous.

Louise Sapsford knows all too well that being underweight attracts just as much attention as those who are carrying excess pounds.

Years of taunts about her tiny frame and desperate attempts to put on weight, led the 24-year-old to take drastic action and publicly acknowledge the problems she faces on national television.

Louise, who weighed just 6 stone 2lbs, was the star of last week's episode of the popular Channel 4 diet show Supersize Vs Superskinny shown on Tuesday evening.

The 5ft 4ins account manager of Brockwell Walk, Wickford, was pitted against man mountain Desroy Gordon, of Witham, Essex, who at 6ft 2in and 28st 13lbs towered over his diminutive challenger, weighing in at more than four times heavier.

The show, presented by Dr Christian Jessen and featuring nutritionist Gillian McKeith, invites both under and overweight people to swap their diets for five days in a bid to recognise where they are going wrong with their own eating.

"I have always been thin," Louise reveals, "I when I was younger it really used to bother me. I never would go out without covering up and wearing a top with sleeves and I got really fed up with people asking me if I was anorexic.

"I signed up to the programme to show people there was nothing wrong with me and I also saw it as my last chance to put on weight."

Despite drinking build up supplements and snacking on cereal bars, crisps and chocolate, Louise's weight refused to budge up the scales.

"I went to the doctor numerous times and was even tested to see if I had Chron's disease," Louise explains, " I even found out later that when I was younger the doctor told my mum to follow me to the toilet to see if I was throwing up after eating. I wasn't but she checked."

Questions over her health and suggestions of eating disorders are not the only problems Louise's size has raised.

Shopping for clothes is also a nightmare for her.

"I range from a UK size 4, which is the US size zero, to a size eight depending on where I shop. I buy a lot of my clothes over the internet and also over order because I know I will have to send so much back because it doesn't fit," Louise says.

"A lot of people say you should be grateful and you have a figure to die for" but it is not much fun when nothing fits as it should. I even have a sewing machine at home so I can take things in."

During the course of the show Louise had to swap her average weekly intake of food for that of Desroy, a self confessed take away addict whose huge portions and love of West Indian food had contributed to his girth.

"I was really scared when I met him," laughs Louise, " he just seemed so huge. But he is a lovely guy and we have stayed friends and talk to each other all the time.

"Although the type of food we ate didn't differ that much it was the huge portion sizes that worried me."

Louise thought she ate a lot of junk food and never finished a meal because she has a tiny appetite.

On an average day though she'd skip breakfast or lunch but snack on crisps, bananas and drink glasses of full fat milk.

At first Louise struggled to finish even one meal, but by the end of the week she did manage to clear her plate and learned that the tiny portions she had been eating were just not enough for her body to function properly.

The real turning point can when she was forced to view close up shots of her own body which showed her spine and hip bones sticking out as well as the revelation that she was in fact two stone under her ideal healthy weight.

"It was horrible looking at those photos," she says, " I realised then how I looked to other people and I was determined to change."

She continues: "Before I would hate going out for meals and thinking I am not going to be able to eat all that' when something was put in front of me and eating at friends' was daunting as I would sit there and panic about being served up a huge dinner."

With Dr Christian's help Louise was able to learn that she could eat more than she realised and that by eating more of the right foods her weight could increase at a healthy rate.

After the initial week long diet swap, both Louise and Desroy were given 12 week diet plans to follow and invited back to see how they had done.

Louise was delighted to have gained half a stone, while Desroy had shifted almost one stone.

"I feel so much better, " says Louise, " I have more energy, my skin and hair are so much better. I used to sit at my desk and want to fall asleep."

Louise is now hoping to gain at least another stone over the next year - taking her to a healthier seven and a half stone.

"I know it is not something that is going to happen over night, but this has really motivated me," she says, "It has made me much more aware of what I eating and what I am putting in my body. It has shown me that if you put your mind to something you really can do it."