Three-Year Improvements in Weight Status and Weight-Related Behaviors in Middle School Students: The Healthy Choices Study

Identifying effective intervention strategies to reduce children's screen time: a systematic review and meta-analysis

BACKGROUND

Excessive screen time ([Formula: see text] 2 h per day) is associated with childhood overweight and obesity, physical inactivity, increased sedentary time, unfavorable dietary behaviors, and disrupted sleep. Previous reviews suggest intervening on screen time is associated with reductions in screen time and improvements in other obesogenic behaviors. However, it is unclear what study characteristics and behavior change techniques are potential mechanisms underlying the effectiveness of behavioral interventions. The purpose of this meta-analysis was to identify the behavior change techniques and study characteristics associated with effectiveness in behavioral interventions to reduce children's (0-18 years) screen time.

METHODS

A literature search of four databases (Ebscohost, Web of Science, EMBASE, and PubMed) was executed between January and February 2020 and updated during July 2021. Behavioral interventions targeting reductions in children's (0-18 years) screen time were included. Information on study characteristics (e.g., sample size, duration) and behavior change techniques (e.g., information, goal-setting) were extracted. Data on randomization, allocation concealment, and blinding was extracted and used to assess risk of bias. Meta-regressions were used to explore whether intervention effectiveness was associated with the presence of behavior change techniques and study characteristics.

RESULTS

The search identified 15,529 articles, of which 10,714 were screened for relevancy and 680 were retained for full-text screening. Of these, 204 studies provided quantitative data in the meta-analysis. The overall summary of random effects showed a small, beneficial impact of screen time interventions compared to controls (SDM = 0.116, 95CI 0.08 to 0.15). Inclusion of the Goals, Feedback, and Planning behavioral techniques were associated with a positive impact on intervention effectiveness (SDM = 0.145, 95CI 0.11 to 0.18). Interventions with smaller sample sizes (n < 95) delivered over short durations (< 52 weeks) were associated with larger effects compared to studies with larger sample sizes delivered over longer durations. In the presence of the Goals, Feedback, and Planning behavioral techniques, intervention effectiveness diminished as sample size increased.

CONCLUSIONS

Both intervention content and context are important to consider when designing interventions to reduce children's screen time. As interventions are scaled, determining the active ingredients to optimize interventions along the translational continuum will be crucial to maximize reductions in children's screen time.

Implementation at-scale of school-based physical activity interventions: A systematic review utilizing the RE-AIM framework

School-based interventions can increase young people's physical activity levels, but few are implemented at-scale (i.e., the expanded delivery of efficacious interventions under real-world conditions into new/broader populations). The Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework can be used to describe the extent to which interventions have been implemented at-scale. The aim of our review was to determine the extent to which studies of school-based physical activity interventions implemented at-scale reported information across the RE-AIM dimensions. We conducted a systematic search of seven electronic databases to identify studies published up to June 2019. A total of 26 articles (representing 14 individual studies) met the inclusion criteria and were analyzed. Eleven studies reported actual or estimated number of students exposed to the intervention; however, the representativeness of these students was rarely reported. Nine studies reported the intervention effect on the primary outcome during scale-up. Ten studies reported the rate of participating schools/teachers; however, none reported on the characteristics of adopters/nonadopters. Eight studies reported intervention fidelity. Eleven studies described the extent to which the intervention was sustained in schools. There was considerable variability in the reporting of RE-AIM outcomes across studies. There is a need for greater consistency in the evaluation, and reporting of, school-based physical activity interventions implemented at-scale.

The evidence for the impact of policy on physical activity outcomes within the school setting: A systematic review

BACKGROUND

Despite the well-established health benefits of physical activity (PA) for young people (aged 4-19 years), most do not meet PA guidelines. Policies that support PA in schools may be promising, but their impact on PA behavior is poorly understood. The aim of this systematic review was to ascertain the level and type of evidence reported in the international scientific literature for policies within the school setting that contribute directly or indirectly to increasing PA.

METHODS

This systematic review is compliant with Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Six databases were searched using key concepts of policy, school, evaluation, and PA. Following title and abstract screening of 2323 studies, 25 progressed to data synthesis. Methodological quality was assessed using standardized tools, and the strength of the evidence of policy impact was described based on pre-determined codes: positive, negative, inconclusive, or untested statistically.

RESULTS

Evidence emerged for 9 policy areas that had a direct or indirect effect on PA within the school setting. These were whole school PA policy, physical education, sport/extracurricular PA, classroom-based PA, active breaks/recess, physical environment, shared use agreements, active school transport, and surveillance. The bulk of the evidence was significantly positive (54%), 27% was inconclusive, 9% was significantly negative, and 11% was untested (due to rounding, some numbers add to 99% or 101%). Frequency of evidence was highest in the primary setting (41%), 34% in the secondary setting, and 24% in primary/secondary combined school settings. By policy area, frequency of evidence was highest for sport/extracurricular PA (35%), 17% for physical education, and 12% for whole school PA policy, with evidence for shared use agreements between schools and local communities rarely reported (2%). Comparing relative strength of evidence, the evidence for shared use agreements, though sparse, was 100% positive, while 60% of the evidence for whole school PA policy, 59% of the evidence for sport/extracurricular PA, 57% of the evidence for physical education, 50% of the evidence for PA in classroom, and 50% of the evidence for active breaks/recess were positive.

CONCLUSION

The current evidence base supports the effectiveness of PA policy actions within the school setting but cautions against a "one-size-fits-all" approach and emphasizes the need to examine policy implementation to maximize translation into practice. Greater clarity regarding terminology, measurement, and methods for evaluation of policy interventions is needed.

RE-AIM analysis of a community-partnered policy, systems, and environment approach to increasing consumption of healthy foods in schools serving low-income populations

While working in partnership with a school district on their wellness policy builds a culture of health, additional strategies are needed to reinforce students eating healthy.

Systematic Review of Natural Experiments for Childhood Obesity Prevention and Control

CONTEXT

The National Academy of Medicine recommends childhood obesity prevention efforts making healthier options the passive choice. This review evaluated the effectiveness of population-level policies and programs from natural experiments for childhood obesity prevention.

EVIDENCE ACQUISTION

The search included PubMed, CINAHL, PsycINFO, and EconLit from 2000 to 2017 for policies evaluated by natural experiments reporting childhood BMI outcomes. The studies were analyzed in 2017-2018. Interventions were classified by environmental focus (food/beverage, physical activity, or both) and stratified by setting (school, community, both). Risk of bias was evaluated for each study.

EVIDENCE SYNTHESIS

Of 33 natural experiments, most (73%) took place in the school setting only. The most common environmental focus in any setting was food/beverage (48%). All four studies that focused on both food/beverage and physical activity in schools demonstrated decreased prevalence of overweight/obesity or BMI z-score by 0.04-0.17. BMI decreased in all four studies in both school and community settings. The largest effect size was a decrease in BMI z-score of 0.5, but most were <0.25. The risk of bias was high for most (76%) studies. Most (63%) of the eight studies with low/medium risk of bias took place in the school setting focused on the food/beverage environment; effects on BMI were mixed.

CONCLUSIONS

Natural experiments evaluating school-based policies focusing on both the food/beverage and physical activity environments (versus targeting only one) consistently showed improvement in BMI. However, most studies had high risk of bias, highlighting the need for improved methods for evaluation of natural experiments for childhood obesity prevention.

Methods for Evaluating Natural Experiments in Obesity: A Systematic Review

BACKGROUND

Given the obesity pandemic, rigorous methodological approaches, including natural experiments, are needed.

PURPOSE

To identify studies that report effects of programs, policies, or built environment changes on obesity prevention and control and to describe their methods.

DATA SOURCES

PubMed, CINAHL, PsycINFO, and EconLit (January 2000 to August 2017).

STUDY SELECTION

Natural experiments and experimental studies evaluating a program, policy, or built environment change in U.S. or non-U.S. populations by using measures of obesity or obesity-related health behaviors.

DATA EXTRACTION

2 reviewers serially extracted data on study design, population characteristics, data sources and linkages, measures, and analytic methods and independently evaluated risk of bias.

DATA SYNTHESIS

294 studies (188 U.S., 106 non-U.S.) were identified, including 156 natural experiments (53%), 118 experimental studies (40%), and 20 (7%) with unclear study design. Studies used 106 (71 U.S., 35 non-U.S.) data systems; 37% of the U.S. data systems were linked to another data source. For outcomes, 112 studies reported childhood weight and 32 adult weight; 152 had physical activity and 148 had dietary measures. For analysis, natural experiments most commonly used cross-sectional comparisons of exposed and unexposed groups (n = 55 [35%]). Most natural experiments had a high risk of bias, and 63% had weak handling of withdrawals and dropouts.

LIMITATION

Outcomes restricted to obesity measures and health behaviors; inconsistent or unclear descriptions of natural experiment designs; and imperfect methods for assessing risk of bias in natural experiments.

CONCLUSION

Many methodologically diverse natural experiments and experimental studies were identified that reported effects of U.S. and non-U.S. programs, policies, or built environment changes on obesity prevention and control. The findings reinforce the need for methodological and analytic advances that would strengthen evaluations of obesity prevention and control initiatives.

PRIMARY FUNDING SOURCE

National Institutes of Health, Office of Disease Prevention, and Agency for Healthcare Research and Quality. (PROSPERO: CRD42017055750).

Racial/ethnic and weight status disparities in dieting and disordered weight control behaviors among early adolescents

BACKGROUND

This study examined whether racial/ethnic minority early adolescents with overweight/obesity are at increased risk of disordered weight control behaviors, defined as unhealthy behaviors aiming to control or modify shape and weight, ranging from self-induced vomiting to the use of dietary supplements.

METHODS

U.S. Middle school children (n=12.511) provided self-report of gender, race/ethnicity, height, and weight as well as dieting and disordered weight control behaviors.

RESULTS

In the entire sample, 25.6% (n=1514) of girls and 16.6% (n=1098) of boys reported dieting within the last month, while 3.5% (n=200) of girls and 2.7% (n=176) of boys reported DWCB. Within all racial/ethnic groups, participants classified as being overweight/obese (34% to 50%) were more likely to report dieting compared to their counterparts without overweight/obesity (9.6% to 29.6%). Racial/ethnic minority children with overweight/obesity had an increased risk of dieting and disordered weight control behaviors compared to their counterparts without overweight/obesity, and, for some outcomes, compared to their White peers with overweight/obesity.

CONCLUSIONS

Racial/ethnic minority early adolescents with overweight/obesity are a particularly vulnerable group for disordered eating.

The Longitudinal Impact of NFL PLAY 60 Programming on Youth Aerobic Capacity and BMI

INTRODUCTION

The NFL PLAY 60 campaign has actively promoted physical activity and healthy eating in youth through programs such as the PLAY 60 Challenge and Fuel Up to PLAY 60. The purpose of the study was to evaluate the impact of NFL PLAY 60 programming on longitudinal trajectories of youth aerobic capacity and BMI.

STUDY DESIGN

Data were from the NFL PLAY 60 FitnessGram Partnership Project, a large participatory research project designed to promote physical activity and healthy eating among Kindergarten through 12th grade children and adolescents.

SETTING/PARTICIPANTS

The programming was led by teachers in school settings across 32 NFL franchise markets. A range of 50,000-100,000 students from 497 schools completed FitnessGram assessments annually starting in 2011 and continuing through 2015. The analysis was conducted in 2015.

INTERVENTION

Adoption of NFL PLAY 60 programming was encouraged but not required and the program implementation was evaluated each year. The adoption was evaluated through self-reported annual survey.

MAIN OUTCOME MEASURES

School assessments of aerobic capacity and BMI were evaluated using FitnessGram standards to calculate the percentage of students meeting the Healthy Fitness Zone for each test. Growth curve modeling was used to estimate the longitudinal trajectories.

RESULTS

About 19% of schools were classified as programming schools. Annual improvements in aerobic capacity were significantly greater in schools that participated in the programs for both girls (3.0%, p<0.01) and boys (2.9%, p<0.01) compared with non-programming schools. The annual improvements in BMI Healthy Fitness Zone achievement were also higher in girls (1.3%, p<0.05) and in boys (1.2%, p<0.05) from schools that participated in the programs versus non-participating schools. Schools that implemented the programs for the entire 4-year period tended to have better improvements in aerobic capacity than schools enrolled for only 2 or 3 years (p<0.05).

CONCLUSIONS

The results of these longitudinal analyses support the utility of the NFL PLAY 60 physical activity promotion programs for improving youth aerobic capacity and potentially helping to reverse the prevalence of overweight/obesity. However, the overall program adoption rate is low.

The MATCH Program: Long-Term Obesity Prevention Through a Middle School Based Intervention

BACKGROUND

Motivating Adolescents with Technology to CHOOSE Health™ (MATCH) has been provided for eight years in North Carolina middle schools with high obesity prevalence.

METHODS

Seventh grade teachers in two schools delivered MATCH lessons in 2009, with one control school. In 2013 students were remeasured and completed a health behavior survey. Outcomes include BMI, BMI z-score (zBMI), weight category, and self-reported behaviors. Comparisons used t tests (continuous measures), Fisher's exact test (categorical measures), and linear mixed models (trend between groups).

RESULTS

Of original participants, 104/189 (55%) of MATCH and 117/173 (68%) of control were remeasured. In the control group, retained participants had lower baseline BMI and were higher percent white. Among all participants, zBMI decreased in MATCH (mean change -0.15 with SD = 0.60) and increased in control (mean change 0.04 with SD = 0.52); between groups p = 0.02. In mixed models for the all overweight subgroup, MATCH had a downward trend in zBMI over time that was significantly different from control (slope MATCH -0.0036 versus control 0.0009; p = 0.01). For shifts in weight category: incidence of obesity was lower in MATCH (13%) versus control (39%); remission of overweight to healthy weight was greater in MATCH (40%) versus control (26%). MATCH participants self-reported lower frequency of intake of sweetened beverages and snacks and hours of weekday TV time than control students.

CONCLUSIONS

MATCH participation can result in long-term prevention of obesity compared to control, with differences in self-reported health behavior changes to support an underlying mechanism for the observed BMI differences.