A great deal of attention is paid to how entertainment impacts girls’ body image; but movies, magazines and certain toys can have an unhealthy impact on boys, too.

According to a new study published by JAMA Pediatrics, 18 percent of boys are extraordinarily concerned with their bodies. Those who are concerned are in greater danger of having other problems, too, such as using drugs or binge drinking. Movies such as 300: Rise of an Empire don’t help matters.

“Ripped male bodies that grace our movie screens have boys thinking they’re inadequate,” writes Eliana Dockterman. She cites research that says a quarter of men today think they’re underweight, and more than half say they feel insecure about their bodies at least once a week. Some spend unhealthy amounts of time working out, use unregulated substances to pack on muscle and can resort to steroids.

“You want people to be concerned enough about their weight to make healthy decisions,” says Dr. Alison Field, associate professor of pediatrics at Boston Children’s Hospital and lead author of the JAMA Pediatrics study, “but not so concerned that they’re willing to take whatever means it takes—healthy or unhealthy—to achieve their desired physique.” (The Atlantic, Time)

Paul Asay has covered religion for The Washington Post, Christianity Today, Beliefnet.com and The (Colorado Springs) Gazette. He writes about culture for Plugged In and wrote the Batman book God on the Streets of Gotham (Tyndale). He lives in Colorado Springs with wife Wendy and his two children. Follow him on Twitter.