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Obesity: Behavioral Interventions that Aim to Reduce Recreational Sedentary Screen Time Among Children


What the CPSTF Found

About The Systematic Review

The CPSTF finding is based on evidence from a Community Guide systematic review completed in 2008 (7 studies with 9 study arms, search period 1966–July 2007) combined with an updated search for evidence in 2013 (42 studies with 53 study arms, search period April 2007–June 2013). The systematic review was conducted on behalf of the CPSTF by a team of specialists in systematic review methods, and in research, practice, and policy related to obesity prevention and control. This finding updates and replaces the 2008 CPSTF findings on Behavioral Interventions to Reduce Screen Time pdf icon [PDF - 202 kB] and Mass Media Interventions to Reduce Screen Time pdf icon [PDF - 179 kB] and replaces the 2000 review on Behavioral and Social Approaches to Increase Physical Activity: Classroom-Based Health Education to Reduce TV Viewing and Video Game Playing pdf icon [PDF - 234 kB].


Childhood obesity has been positively associated with time spent watching TV (Marshall, et al. 2004, Tremblay, et al. 2011). The American Academy of Pediatrics (AAP) recommends no more than 2 hours per day of screen time for children 2 years and older and none for children younger than 2 years (American Academy of Pediatrics 2001). In the U.S., children aged 8-18 years report an average of 7 hours of screen time per day, of which 4.5 hours are spent watching TV content, that is, TV programs, DVDs, or movies, viewed on a TV, computer, cell phone, or other device (Rideout, et al. 2010). Children aged 5 years and younger spend an average of 2 hours per day with screen media (i.e., TV, DVDs, videos, video/computer games), of which approximately 1.5 hours are spent watching TV or videos (Rideout 2011).

Summary of Results

A combined total of 49 studies with 62 study arms qualified for the review.

  • Screen Time Outcomes
    • Duration of composite screen time: median decrease of 26.4 minutes/day (interquartile interval (IQI): ‑74.4 to ‑12.0 minutes/day; 34 study arms)
      • Screen-time-only interventions: median decrease of 82.2 minutes/day (IQI: ‑105.4 to ‑52.1 minutes/day; 11 study arms)
      • Screen-time-plus interventions: median decrease of 21.6 minutes/day (IQI= ‑38.4 to ‑12.9 minutes/day; 23 study arms)
  • Physical Activity Outcomes
    • Accelerometer counts:
      • Screen-time-only interventions: no study arms
      • Screen-time-plus interventions:
        • Screen time contingent on physical activity: median increase of 130.0 counts per day (range: 127.8 to 150.0 counts/day; 3 study arms)
        • Screen time not contingent on physical activity: median increase of 66.0 counts per day (range: 40.8 to 1150.0; 4 study arms)
        • Screen time not contingent on physical activity: median increase of 3.6 counts per minute (range: ‑12.3 to 18.0; 3 study arms)
    • Other physical activity outcomes (e.g., pedometer steps of physical activity, score on a fitness test, and duration of physical activity):
      • The body of evidence for both interventions suggests a positive effect, but the magnitude of effect was small.
  • Dietary Outcomes
    • Total energy intake (kcal/day):
      • Screen-time-only interventions: decrease of 75 kcal/day (1 study arm)
      • Screen-time-plus interventions: decrease of 117.9 kcal/day (IQI: ‑373.1 to 28.5 kcal/day; 5 study arms)
    • Other dietary outcomes (e.g., eating meals or snacking with the TV on, daily snack intake, sugar sweetened beverage intake, and fruit and vegetable intake):
      • The body of evidence for both interventions suggests a positive effect, but the magnitude of effect was small.
  • Weight-Related Outcomes
    • Body mass index (BMI): median decrease of 0.09 (IQI: ‑0.44 to ‑0.04; 15 study arms)
    • BMI Z-score (i.e., a standard deviation score indicating how many units (of the standard deviation) a child's BMI is above or below the average BMI value for their age group and sex): median decrease of 0.13 (IQI: ‑0.23 to ‑0.01; 14 study arms)
  • Obesity Prevalence
    • Proportion of participants obese: median decrease of 2.3 percentage points (IQI: ‑4.5 to ‑1.2 percentage points; 14 study arms)

Summary of Economic Evidence

The economic review included three models from two studies that were based on randomized controlled trials included in the effectiveness review. A general conclusion about cost-effectiveness could not be determined because results from this small body of evidence were mixed. Monetary values are reported in 2013 U.S. dollars.

Intervention cost:

Intervention cost included the cost of measuring and tracking devices, staff time in counseling and education sessions, training, educational materials, and supplies.

  • The cost per person per year was $43 for a screen-time-plus intervention and $248 for a screen-time-only intervention.
  • The higher cost for the screen-time-only intervention was partially explained by the inclusion of the electronic monitoring device, a greater number of sessions, and labor costs associated with tracking and monitoring outcomes.

Healthcare Cost and QALY:

Healthcare costs are averted and quality-adjusted life years (QALYs) are saved when the intervention reduces morbidity and mortality associated with overweight-related diseases and conditions.

  • The models used in both the screen-time-plus and screen-time-only studies drew from longitudinal data of U.S national surveys to estimate that each prevented case of overweight in adulthood would avert about $4000 in healthcare costs and increase QALY saved by 0.71.


Cost-effectiveness is measured as net cost (intervention cost minus healthcare cost averted) per QALY saved. An intervention is considered cost-effective when cost-effectiveness is less than or equal to a conservative threshold of $50,000 per QALY saved.

  • Both studies evaluated the models based on a sensitivity analysis of key determinant variables of cost-effectiveness: size of intervention group; intervention effectiveness; transition of weight status to adulthood; intervention cost per person; and 50% relapse to overweight.
  • Both studies modeled the screen-time-plus intervention, finding it to be cost-effective.
    • Cost per QALY saved ranged from $7,500 to $22,900 depending on assumptions made.
  • One study modeled the screen-time-only intervention and found the intervention was not cost-effective.
    • Cost per QALY saved ranged from $26,000 to $115,000 depending on assumptions made.


Based on results for interventions in different settings and populations, findings are applicable to the following:

  • U.S. or other high- or medium-income countries
  • Children ages 13 years and younger
  • Males and females
  • All racial and ethnic populations studied
  • All socioeconomic levels
  • Normal weight, overweight, and obese populations
  • Urban and suburban settings

Evidence Gaps

Each Community Preventive Services Task Force (CPSTF) review identifies critical evidence gaps—areas where information is lacking. Evidence gaps can exist whether or not a recommendation is made. In cases when the CPSTF finds insufficient evidence to determine whether an intervention strategy works, evidence gaps encourage researchers and program evaluators to conduct more effectiveness studies. When the CPSTF recommends an intervention, evidence gaps highlight missing information that would help users determine if the intervention could meet their particular needs. For example, evidence may be needed to determine where the intervention will work, with which populations, how much it will cost to implement, whether it will provide adequate return on investment, or how users should structure or deliver the intervention to ensure effectiveness. Finally, evidence may be missing for outcomes different from those on which the CPSTF recommendation is based.

Identified Evidence Gaps

  • Research is needed to identify the combinations of intervention components that are most effective and determine which components are critical to success.
  • Future studies should explore the effect of intervention intensity and duration on key outcomes and assess long-term effectiveness. For example, does a low-intensity, 1-year intervention show greater effectiveness than a high-intensity, 3-month intervention?
  • More information is needed on intervention effectiveness among teens older than 13 years of age and adults. It also would be helpful to learn more about intervention effectiveness in rural settings, among people of all ages.
  • Researchers should consider other benefits and implications of reduced screen time. For example, does a reduction in screen time mean other sedentary behaviors will be substituted (e.g., reading for leisure, listening to music, time spent on homework)? And, do reductions in screen time lead to other health benefits, such as improved sleep quality?

Study Characteristics

  • Studies were randomized controlled trials (RCT) or group RCTs (37 studies), single group before-after studies (5 studies), before-after with a comparison group (4 studies), and a non-randomized trial (1 study).
  • Included studies were conducted in the United States (30), Australia (6), the United Kingdom (4), Canada (2), France (1), the Netherlands (1), New Zealand (1), Sweden (1), and Switzerland (1).
  • Studies mostly targeted children aged 13 years and younger (46 studies). No studies targeted adolescents aged 14-18 years.
  • Of the 11 screen-time-only studies, 6 were high intensity, 3 were low intensity, and 2 had a high and a low arm. Of the 35 screen-time-plus studies, 22 were high intensity, 11 were low intensity, and 2 had a high and a low arm.
  • Nine studies were conducted in lower economic status populations. Of these, three studies targeted low-income African-American children, two studies targeted Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) participants, one study targeted Head Start program participants, and three studies targeted disadvantaged children.
  • Six studies targeted overweight or obese populations.
  • Family-based social support was the most common intervention component.
  • Evaluated programs were most commonly implemented in schools (20 studies), and of these 90% were screen-time-plus interventions.