Do you have skinny genes Each woman's feelings about her size and shape are down to her genetic make-up, say scientists
Research carried out at Michigan State University
The 'thin ideal internalisation' of identical and fraternal twins was studied
Findings published in International Journal of Eating Disorders
07:39 GMT, 3 October 2012
Whether you feel fat, thin, average or you simply don't care may have nothing to do with the chocolate cake you ate (or didn't eat) yesterday.
It may instead be down to the genes you inherited from your parents.
A woman's body image and desire to be thin stems chiefly from her genetic make-up, according to new research carried out at Michigan State University (MSU).
Mothers pass on their 'thin idealisation' to their daughters, so Harper Beckham is likely to inherit Victoria's fondness for the skinny leg, left, and Lourdes may enjoy working out like her mother Madonna, right.
Scientists found that nearly half of the reason why some women feel more pressure to be slim is down to their 'genetic programming'.
Scientists found that nearly half of the reason why some women feel more pressure to be slim is down to their 'genetic programming', which causes some women to be more susceptible to body image issues and eating disorders.
Georgia May Jagger, left, will probably have the same attitudes towards body shape as her mother, Jerry Hall.
So Harper Beckham is likely to inherit Victoria's prediction for a tiny waist; Georgia May Jagger could take after her mother Jerry Hall when it comes to staying toned and slim; and Lourdes Ciccone will probably follow her mother Madonna into the gym.
The research challenges the popular notion that young women are pressured into idolising thinness due to their environments, which are replete with airbrushed photos of celebrities and 'size zero' models.
Scientists carried out the study by examining differing attitudes between identical and fraternal twins.
Lead researcher at MSU Jessica Suisman said: 'We're all bombarded daily with messages extolling the virtues of being thin, yet intriguingly only some women develop what we term 'thin ideal internalisation.
'This suggests that genetic factors may make some women more susceptible to this pressure than others.'
study – which is being published in the International Journal of Eating Disorders –
assessed more than 300 female twins from the MSU Twin Registry between
the ages of 12 and 22.
Researchers measured how much the twins wanted to look like people from films, television and magazines.
the levels of their 'thin idealisation' were assessed, identical twins
(who share 100 per cent of their genes) were compared with fraternal
twins (who share 50 per cent, just like standard brothers and sisters).
Identical twins Ashley and Mary Kate Olsen, left, would be likely to have the same 'thin idealisation' because they share exactly the same genes, but it would probably differ to that of their younger sister Elizabeth, right.
results showed that identical twins have closer levels of thin
idealisation than fraternal twins – suggesting a 'significant' role for
This means that identical twins such as Ashley and Mary Kate Olsen are more likely to have the same attitudes towards body image and eating as each other, but will not necessarily share these attitudes with their younger sister, actress Elizabeth.
Further research put this figure at
43 per cent, meaning half of the reasons women differ in their
idealisation of thinness can be explained by their genetic make-up.
Results did showed that environmental influences are also important, especially experiences not shared between twins.
factors include one twin
being involved in a weight-focused sport like dance, one twin observing
more media that promotes thinness, or one twin having friends
who place importance on weight.
A woman's unique DNA dictates how she feels about her body – more so than environmental factors such as diet and the media.
Ms Suisman added: 'We were surprised to find that shared environmental factors – such as exposure to the same media – did not have as big an impact as expected.
'Instead, non-shared factors that make co-twins different from each other had the greatest impact.
'The broad cultural risk factors that we thought were most influential in the development of thin-ideal internalisation are not as important as genetic risk and environmental risk factors that are specific and unique to each twin.'
Kelly Klump, professor of psychology at MSU and co-author of the study, said a broad range of factors can contribute to the development of eating disorders.
She said: 'This study reveals the need to take a similar approach to the ways in which women buy in to pressure to be thin, by considering how both genetic and environmental factors contribute to the development of thin-ideal internalisation.'