Very Obese Teens Take Bigger Risks

"Take bigger risks"? They are at bigger risk just from being obese.

Extremely obese teens seem just as likely to engage in some risky behaviors as their normal-weight peers -- but sometimes in more dangerous ways, a national survey found.

For instance, even though very obese teenage girls were at much lower risk for ever having sexual intercourse (OR 0.47, 95% CI 0.26 to 0.85), they were significantly more likely to have been under the influence of alcohol or drugs during their last sexual encounter (OR 4.57, 95% CI 1.18 to 17.61), according to Meg H. Zeller, PhD, and colleagues from Cincinnati Children's Hospital Medical Center.

Imagine how much their partners had to intoxicate to do the deed.

The study, based on a survey of more than 9,000 high school students, also suggested that very obese girls were twice as likely to have had sex before age 13, although the result was not statistically significant (OR 2.08, 95% CI 0.48 to 8.97), the researchers reported in the May Pediatrics.

"These findings were a surprise to us," Zeller told MedPage Today.

"We had thought that, because of their social isolation and the stigma associated with extreme obesity, these kids would be engaging in fewer risky behaviors than typical adolescents," she said in an interview.

Previous studies of obese adolescents, those with a body mass index (BMI) ≥95th percentile for their age and gender, have shown they are equally or even less likely to engage in certain risky behaviors, Zeller and colleagues noted in their background material.

At the same time, those studies found that obese girls were more likely to take certain risks, such as engaging in sex before age 13, having multiple sexual partners, and not using contraceptives.

However, little is known about risk-taking behaviors among extremely obese adolescents, those with a BMI ≥99th percentile for age and gender.

To address this, Zeller's group analyzed data from the 2007 Youth Risk Behavior Survey (YRBS), a school-based survey administered by the CDC every two years to a nationally representative sample of students in grades nine to 12.

Self-reported height and weight were used to calculate BMI for the teens.

The study analyzed YRBS data for 410 high school students who were extremely obese and 8,669 students of normal weight.

In addition to early sexual activity, Zeller and colleagues found that very obese girls were more likely than their healthy-weight peers to engage in these risky behaviors:

Ever tried cigarette smoking, OR 2.04 (95% CI 1.31 to 3.20)
Current cigarette smoking, OR 2.28 (95% CI 1.19 to 4.37)
Current smokeless tobacco use, OR 4.56 (95% CI 1.22 to 17.15)
Ever used steroids without a prescription, OR 3.59 (95% CI 1.03 to 12.44)
Very obese boys also were more likely to have ever tried smoking (OR 1.52, 95% CI 1.15 to 2.01) and to have smoked cigarettes before age 13 (OR 1.41, 95% CI 1.02 to 1.96).

"Obese adolescents are already at greater risk for the development of additional chronic health conditions, the likes of which may be exacerbated by cigarette smoking, resulting in compound health risk," Zeller and colleagues wrote.

The likelihood of serious consideration of suicide was increased for both very obese girls (OR 1.71, 95% CI 1 to 2.92) and boys (OR 1.61, 95% CI 0.99 to 2.61).

The results of nutritional child abuse.