A teenaged girl's weight can influence how many partners she sleeps with and whether or not she uses condoms during sex, according to a new study that suggests a woman's body image can affect her willingness to take sexual risks.
The University of Pittsburgh study, published in the November issue of Pediatrics, also suggests a girl's ethnicity may play a role in her participation in risky sexual behaviours.
Girls who were sexually active and overweight - or thought they were overweight - were less likely to use condoms than normal-weight sexually active girls. Underweight girls also were less likely to use condoms.
The study looked at 7,200 high-school students aged 12 to 18. They had been asked about their sexual activity for the 2005 Youth Risk Behavior Surveillance survey. Half reported ever having had sex.
African-American girls who believed they were underweight were less likely to use condoms than girls who accurately perceived their weight. But African-American girls who saw themselves as overweight were more likely to report having four or more sexual partners.
The findings were flipped for Caucasian girls. Those who viewed themselves as underweight were more likely to have had sex - and to have had four or more sexual partners. Overweight Caucasian girls, meanwhile, were less likely to use condoms.
Cultural perceptions of weight probably underlie the differences, said Aletha Akers, an obstetrician and gynecologist at Magee-Womens Hospital of the University of Pittsburgh Medical Center who conducted the study with her colleagues.
"In predominantly Western culture, thinness seems to be the norm. That's what media drives as beautiful. That's what you see on TV and with models and magazines. In studies that have looked at what partners desire, most Western men tend to also gravitate towards ideals of beauty that are associated with thinness," Dr. Akers said.
"We think that's why girls who perceived themselves as underweight may in fact have more opportunities for partnering. … Whereas for girls who are overweight or perceive themselves to be overweight, they may perceive themselves as outside the beauty norm and may be less likely to negotiate condom use with their partners. We hypothesize they may be afraid that their partner will leave them."
Dr. Akers pointed out that in African-American culture, "beauty is associated with more curviness."
"We think that may be why girls who perceive themselves as overweight - whether accurately or not - may be the ones who are more sexually active. They may have more opportunities for partnering. Whereas their underweight counterparts may see themselves as outside the norm of beauty for their cultural group."
Dr. Akers said the findings could be used in sexual-health education.
"If, in fact, certain girls may indeed be less likely to negotiate condom use because they may have lower self-esteem and lower body image, that would be something that would be important to incorporate into our sex-education programs," she said. "Making sure that girls, regardless of their weight, feel competent to negotiate sexual behaviours with partners is something that could be emphasized."