Sociologists at Penn State found a correlation between the obesity rates in high schools and the odds of obese high school students getting pregnant.

According to the study, the higher the obesity rate in a high school, the more likely obese students were to get pregnant. On the other hand, the prevalence of obesity in a high school did not change non-obese students' risk of childbearing.

Essentially, the study suggests that obese teenage girls have more opportunities to date (and have sex) when they attend schools where the obesity rate is high. When 17 percent or more of the students in a high school was obese, the odds of pregnancy for obese students surpassed those for non-obese students.

The reason? "In general, we tend to partner with people who look like us," said Michelle Frisco, associate professor of sociology and demography at Penn State.

Dr. Jennifer Buher Kane, co-author of the study, said that the research shows that obese females are more likely to engage in risky sexual behavior because they feel less empowered in their relationships. She added that obese girls are also more likely to use drugs or alcohol before sex, which makes unprotected sex more likely.

"We need to teach all young women to make better and smarter decisions," said Frisco. "A one-size fits all approach to understanding adolescent pregnancy and childbirth doesn't work."