Six-second test that tells you the shape you're in

The Body Volume Index Scanner, developed originally to help clothing manufacturers, tells it to you straight. In just six seconds. In fact, it produces such a detailed picture of the body that it has has been hailed the Truth Machine.

BMI, which dates back more than a century, uses just weight and height in its calculations.

That simple method leads to super-fit muscular sportsmen such as rugby star Johnny Wilkinson being classed as obese. But the Body Volume Index Scanner also takes account of body shape, fat distribution and muscle.

It shines a white light on users - stripped to their underwear - for six seconds while it generates the picture of their body structure. They are then told where there is too much fat, or too little, and how dangerous that is.

The scanner was developed by Birmingham-based Select Research for clothes firms to survey body shapes and mass-produce items in the right sizes.

But managing director Richard Barnes had a 'lightbulb' moment when he realised the scanner could also help combat anorexia by giving sufferers an accurate representation of their bodies.

He said: "If someone who is overweight goes on a crash diet and becomes dangerously thin, they have gone too far and the machine could detect that.

"There is an obsession about body size today, particularly among women.

"This machine provides a reality check - it could be described as a truth machine.

"Anorexics who have been through the scanner find it hard to believe it is them.

"I believe it could help them and it will help medical professionals to detect anorexics because the machine recognises that particular body composition."

Volunteer Sandra-Eve, 59, who used the scanner to tackle weight problems caused by an underactive thyroid, said: "I went for three scans over six months and I could see the progression as I lost nearly two stone."

The BVI scanner could help paint a clearer picture of the obesity crisis in the UK after an alarming report earlier this year revealed Britons are the fattest people in Europe.

A quarter of women and a fifth of men in the UK are now so overweight that their health is at serious risk.

British women head the EU league, with 23 per cent clinically obese under the BMI system. Men fare little better, with 22.3 per cent obese - behind only Malta.