Okay girls, relax, 20.85 is now the perfect body!

If new research is to be believed, and most women will!, the ever growing millions of women who nip, tuck, plump and stitch in search of the body beautiful could be wasting their money.

A team of British scientists says that the secret of an attractive figure lies not in emulating Pammy's bust or Kylie's bum, but in the age-old formula of staying trim.

The researchers have discovered the perfect body mass index, the standard measure of height against weight, for any woman looking to attract a mate is a score of 20.85, that they say, is more influential than any of the other features on display.

Their research shows that men are attracted to a certain body mass because it is associated with better health, which conflicts with previous research which has said that waist-to-hip ratio (WHR) is the most important factor, with curvaceous shapes corresponding to high fertility.

But now these results from the team at University College London and University of Newcastle upon Tyne, clearly illustrate that BMI is even more critical, and accounts for 75 per cent of body attractiveness, while waist-hip ratio, leg-length, and other body parts made up the rest.

Psychologist Viren Swami of UCL, who helped to lead the study, says their findings show that BMI is a better predictor of attractiveness than curves.

Apparently they found that as the images became more curvaceous, but with a higher BMI, they were seen as less attractive.

The popularity of curvaceous singers such as Jennifer Lopez and Beyonce has been credited with starting a new market in "buttock augmentation", and the UK has seen an astonishing growth in cosmetic plastic surgery.

This research involved nearly 700 men and women in Britain and Malaysia.

Participants were shown images of real women in five BMI categories, from emaciated (below 15); to obese (over 30), and were then asked to score how beautiful they considered each one.

In the UK, the most attractive BMI was found to be 20.85 for both men and women, while in less developed countries, it was slightly higher.

Interestingly, the results also show that ratings of attractiveness fell away very quickly either side of this figure, with an overweight woman having half the attractiveness of a woman with the perfect BMI. The fall in attraction rating was even sharper for very thin women.

Mr Swami says that BMI accounted for approximately 12 times more variance than WHR, which suggests that BMI is a considerably stronger determinant of bodily attractiveness than WHR.

He says this is consistent with the fact that successful female fashion and glamour models all fall within a narrow BMI range.

They believe that men are attracted to the perfect BMI because it is a sign of good reproductive potential.

Another view is that BMI is the first measure used by men to assess a potential partner, while another theory suggests the preferred shapes in the study simply reflect media images rather than real life.

Research on Miss America contestants and Playboy centrefolds has shown that the ideal became increasingly thinner over a 20-year period, while women actually became 4 per cent heavier.

The study is published in the current edition of the journal Body Image.