Eating disorders are on the rise among American men. In fact, the National Eating Disorder Association reports that one million men suffer from an eating disorder, the three main types being anorexia nervosa, bulimia nervosa, and binge-eating disorder. Investigators often speculate as to the root causes of this particular type of mental disorder. Now, new research examines one possibility that may be linked to purging behavior: sexual harrassment.

Men who experience high levels of sexual harassment are much more likely than women to induce vomiting and take laxatives and diuretics in an attempt to control their weight, according to a new report from Michigan State University researchers.

The design of the study sought to explore the effects of sexual harassment on body image and eating behaviors in both women and men. Lead author NiCole Buchanan and colleagues surveyed 2,446 college-aged participants, including 731 men, on their experiences with sexual harassment, body image, and eating behaviors.

As expected, women participants reported more harassment, greater overall weight and shape concerns, and disordered eating behavior (including binges) in response to that harassment, said Buchanan.

However, Buchanan also learned that men are significantly more likely to engage in "compensatory" purging behaviors after high levels of sexual harassment.

"Traditionally, there has been a misperception that men are not sexually harassed," said Buchanan, associate professor of psychology. She explained that sexual harassment comes in many different forms, including peer-on-peer harassment, and can lead to symptoms of anxiety and depression, concerns about body image, and dysfunctional eating. A simple Google search reveals that the primary definitions of sexual harassment are legally-based and often framed within a context of employment.

"And while women do experience much higher rates of sexual harassment, when men experience these kinds of behaviors and find them distressing, then you see the same types of responses you see in women - and in the case of compensatory behaviors, even more so." Her study, according to Buchanan, is the first to make that connection.

Buchanan said there may be certain features of sexual harassment that are particularly powerful in triggering purging behaviors in males and that further research is needed to examine this possibility. Her study, online now, will appear in an upcoming print issue of the research journal Body Image.

"Although boys and men have lower rates of weight/shape concerns and eating disturbances, these issues are still significant and warrant intervention," she said.

The prevalence of eating disorders among a random sample of students at a large university found 3.6 percent of the men exhibiting symptoms of the condition. Unrelated research finds that only 10 percent of men with an eating disorder seek treatment - debatably, the same low percentage as women who seek help for this serious, life-threatening condition.