Childhood rape linked to weight gain

Girls who have been raped are more likely to become overweight than other young women, according to a study that strengthens links between sexual abuse and binge eating.

Research by the University of Queensland has found that female victims of childhood sexual abuse are 85 per cent more likely to be overweight by the age of 21.

The findings were only true for penetrative sexual abuse, and for women, not men, indicating that it may be specific to the way females process trauma.

Lead investigator Dr Abdullah Al Mamun said this was the biggest population-based study to explore the links between weight and sexual abuse.

"It really indicates that we really need to be looking beyond the mental health consequences of assault to also assess the links with physical health," Dr Mamun said.

Researchers surveyed about 2,500 men and women aged 21 and found 7.5 per cent had intercourse against their will before the age of 16.

While the men had no significant weight difference to other men, female victims were much more likely to have a body mass index (BMI) over 25, making them officially overweight.

Dr Mamun said the link was not entirely understood but it was believed sexual abuse victims were more inclined to be heavier because they would "comfort eat" to cope.

"What they have been through is very traumatic, so binge eating may be a way of dealing with that emotional overload," he said.

"The fact that men did not do the same shows that sexes process these things very differently, and it may reflect the specific body image pressures on women."

The researchers also suggest that female victims may purposefully try to alter their lifestyles to increase weight as a means of protecting themselves from further abuse.

Eating disorders and sexual abuse have long been linked but there was little data to prove the connection.

Previous studies have looked solely at women or obese populations, or were relatively small. The scale and comprehensiveness of this new study added new strength to the theory, Dr Mamun said.

He said the study had important implications for clinicians who treated sexual abuse victims.

NSW Rape Crisis Centre manager Karen Willis said the findings were not a surprise. Rape caused severe psychiatric injury that took a toll on both body and mind, she said.

"When you traumatise a child to that extent the impact is going to be broad and extreme," Ms Willis said.