More Evidence Needed to Determine Effectiveness of Classroom-Based Health Education Focused on Reducing Television Viewing and Video Game Playing in Increasing Physical Activity

Regular physical activity is associated with a healthier, longer life. Physically active people have a lower risk of heart disease, high blood pressure, diabetes, obesity, and some types of cancer. Despite all the benefits of physical activity, most people in this country are sedentary. Given that regular physical activity helps people enjoy better health, an important question is: what strategies work best in helping people become more physically active?

According to the Community Guide rules of evidence, available studies provide insufficient evidence to determine the effectiveness of health education classes focused on reducing television viewing and video game playing in increasing physical activity behavior, because of inconsistent results for that outcome. This does not mean that these interventions are ineffective, but that additional research is needed to determine their effects.

• In elementary school classrooms, as part of a general health curriculum, regular classroom teachers taught classes that specifically emphasized decreasing the amount of time spent watching television and playing video games. Classes included instruction in behavioral management techniques or strategies such as self-monitoring of viewing behavior, limiting access to television and video games, and b udgeting time for television and video. All studies included a “TV turnoff challenge” in which the students were encouraged not to watch television for a specified number of days. Activities that required greater energy expenditure than watching television or playing video games were not specifically recommended. Parental involvement was a prominent part of the intervention, and all households were given automatic television use monitors.

• Available studies provide insufficient evidence to determine the effectiveness of classroom-based health education focused on reducing television viewing and video game playing in increasing physical activity. Such classes do, however, have additional benefits in terms of reducing television watching and may lower levels of adiposity. More research is needed into the links between reducing time spent watching television or playing video games and increasing physical activity.



• Two of the studies examined effects on adiposity. One study showed significant decreases in both body mass index, or BMI (2.3%) and skinfold measurements (11.5%). One study showed a 24.2% reduction in the prevalence of obesity among girls and no change among boys, as well as higher rates of obesity remission in the intervention group compared with the control group. (Obesity remission occurs when a child who is defined as obese “grows into” his or her weight: body weight does not decrease but the child grows in height, thus reducing the BMI to a level that is no longer considered obese.) Because there was no evidence of effect on levels of physical activity, it is thought that reductions in adiposity might be the result of lower levels of snacking while watching television. An alternative explanation is that the interventions caused an increase in light physical activity that was not captured by the methods used.

Publications:

• American Journal of Preventive Medicine – Am J Prev Med 2002: 22 (4S); 73-107 . A report on e vidence and findings.
• MMWR/Recommendations and Reports – October 26, 2001/Vol. 50/ No. RR-18. A report on findings.

The findings and conclusions in this report have not been formally disseminated by the Centers for Disease Control and Prevention and should not be construed to represent any agency determination or policy.

The Guide to Community Preventive Services (Community Guide) provides recommendations on population-based interventions to promote health and to prevent disease, injury, disability, and premature death, appropriate for use by communities and healthcare systems. For more information about the Community Guide (including links to publications and a variety of resources) see www.thecommunityguide.org and for more information about the physical activity review see www.thecommunityguide.org/pa/.

This information is in the public domain. Copying and disseminating freely is encouraged. However, citation to source is appreciated.

Updated – January 23, 2008