Published: 08/09/2005, Volume II5, No. 5972 Page 38

Supermodels have been criticised as bad role models for young women because of their unnatural thinness.

They have even been linked to increases in eating disorders such as anorexia.

But why are they perceived to be attractive? In their study 'Supermodels: stick insects or hourglasses?', published in The Lancet, psychologist Martin Tovée and colleagues at Newcastle University's psychology department compiled a database of 300 fashion models, 300 glamour models, 300 'normal' women and a sample of women with eating disorders.

Previous studies suggest there is an optimum waist-hip ratio for female attractiveness: corresponding to a fat distribution that gives optimum fertility.

But the key finding of Tovée's study was that fashion models were, on average, 11cm taller than other groups.

Both fashion and glamour models were rated significantly underweight on bodymass index, but were heavier than anorexic women. Fashion and glamour models had a waist-hip ratio close to optimum and tended to have an hourglass figure, as shown by the busthip ratio.

Fashion and glamour models had similar measurements, although glamour models are usually regarded as more curvaceous than fashion models.

The key difference may be height, creating an illusion. Supermodels appear thinner than they really are simply because they are so tall. A shorter hour-glass figure will appear more curvaceous.

The message is that supermodels are tall and curvaceous, and if you're a shorter woman, dieting will not make you look like a Vogue covergirl.

How many other illusions are we entrapped by in the NHS when we compare our service with others? Do 'supertrusts' appear better than they are simply because we are unaware of distortions in our perception?

The resistance of reputation to actual performance data suggests, until the NHS moves toward a respect for figures rather than looking up in awe at supermodels, we will not see improved performance. We need to be careful when choosing our role models.

Dr Raj Persaud is consultant psychiatrist at South London and Maudsley trust and Gresham professor for public understanding of psychiatry.