Teen physical activity and screen time influenced by friends

The company a teen keeps can influence how much time they spend either in front of a screen or participating in healthy physical activity, finds a new study in the American Journal of Preventive Medicine.

Researchers analyzed data from 2009-2010 E.A.T. (Eating and Activity among Teens) 2012 survey, conducted in 20 middle schools and high schools in Minneapolis/St. Paul, Minn.

Results from the survey found that adolescents become increasingly independent from their parents while relying more upon behavioral cues from their friends.

In addition, the study yielded a few surprises that challenged some gender-related preconceived notions about teen leisure time, said lead study author John R. Sirard, Ph.D., assistant professor of the kinesiology program and Youth-Next Research Center at the University of Virginia.

"We anticipated we'd see a pretty consistent association between male adolescents and their male friends for both screen time—television, computer or video games, but not phone apps—and physical activity. We thought the 'jocks' would hang out together or active boys with other active boys and that if a boy was inactive, the same thing would occur."

Overall, boys engage in more moderate to vigorous physical activity and screen time than girls. Both the physical activity and screen time of boys was found to be more influenced by the behaviors of their female friends than their male friends.

For girls, physical activity was associated with that of both their male and female friends'. However, females' screen time was associated with their male friends' screen time but not with their female friends' screen time.

The results are consistent with earlier research that finds that the social aspects of sports are most appealing to girls, the researchers say.

"We know physical activity has consistent benefits for adolescents and adults," said Sirard. Obesity itself isn't contagious, he said, but the behaviors that affect weight status are contagious—what goes in (i.e. food), and what goes out or is expended (i.e. physical activity).

"The authors add to our current knowledge base by separately examining males and females. They showed similar results to previous literature that found social aspects of physical activity to be particularly important for females," said Karin Allor Pfeiffer, Ph.D. of the department of kinesiology at Michigan State University.

"Also, as the authors noted, longitudinal research is necessary to help establish causality," said Pfeiffer. "In other words, do friends become more like each other in their behaviors or do like-minded friends find each other?"

Sirard and his colleagues recommend real-world oversight to effect healthy changes. "If we're going to allow our kids screen time, it should be supervised or limited," he said. "They can play an active video game instead of a passive one, or go outside and actually play the real game."