One medical risk associated with both overweight and underweight high school age Americans is mental illness, including suicide. Researchers at the Centers for Disease Control and Prevention wondered whether weight-conscious teens who see themselves as too fat or too thin have a higher risk of suicide, regardless of how much they actually weigh.

What the researchers wanted to know: Are teens who see themselves as very overweight or very underweight more likely to contemplate suicide, regardless of their actual size?

What they did: Researchers analyzed data from a national survey of 13,601 high school students. Students indicated their actual height and weight. They then responded to the question "How do you describe your weight?" with five choices ranging from "very underweight" to "very overweight." To determine the student's risk of suicide, the researchers asked: "During the past 12 months, did you ever seriously consider attempting suicide?" and "During the past 12 months, how many times did you actually attempt suicide?"

What they found: Teens who answered either "very underweight" or "very overweight" were more likely to indicate suicidal thoughts or behaviors than those who answered "about the right weight." Further, an adolescent's perception of his or her weight was a better indicator of suicidal thoughts and behaviors than a more objective measure (body mass index) calculated from actual weight and height. Ethnicity played an important role in determining whether "very underweight" or "very overweight" drew the strongest indications of suicidal behavior. Attempted suicide responses occurred more often when black and Hispanic teens identified themselves as "very underweight," but attempts were more likely when white adolescents saw themselves as "very overweight."

What this study means to you: Teens who see themselves as too fat or too thin might have a higher risk of suicide. Parents who see warning signs–for example, their teen making disparaging comments about his or her body–may want to seek professional help. A psychiatrist or psychologist can help determine if the teen exhibits risk factors linked to suicide.

Caveats: While the authors did find a correlation between perceived weight and suicidal thinking, they did not establish a cause-effect relationship between mental illness, suicide, and perceived body weight. Researchers believe that suicide results from a combination of several factors, including mental illness, family function, and access to firearms, in addition to body image. Also, the study did not take into account those adolescents who died by suicide or those 12 percent who did not answer the suicide attempt question on the survey. Since those 12 percent of respondents tended either to be obese, to perceive themselves as "underweight," or to engage in unhealthy eating practices, the authors say if they had been included it may have strengthened the association between suicide and weight perception in the study.

Find out more: The American Academy of Pediatrics has a Web page on teen suicide and obesity, including links to information about nutrition and exercise.

Also check out the home page for body mass index of the Centers for Disease Control and Prevention.

Read the article: Eaton, D.K., et al. "Associations of Body Mass Index and Perceived Weight With Suicide Ideation and Suicide Attempts Among U.S. High School Students." Archives of Pediatric & Adolescent Medicine. June 2005, Vol. 159, pp. 513-519.

Abstract online: http://www.archpedi.ama-assn.org