1. Childhood Obesity Prevention Programs: Comparative Effectiveness
Prepared for:
Agency for Healthcare Research and Quality (AHRQ)
Childhood Obesity Prevention Programs: Comparative Effectiveness
This slide set is based on a comparative effectiveness review (CER), Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis, Comparative Effectiveness Review No. 115, which was developed by the Johns Hopkins University Evidence-based Practice Center, Baltimore, MD, for the Agency for Healthcare Research and Quality under Contract No I and is available online at
CERs are comprehensive systematic reviews of the literature that usually compare two or more types of interventions with usual care for the same disease. For this CER, the existing body of evidence on the relative benefits and adverse effects of currently available programs for preventing childhood obesity was reviewed. The review evaluated 131 reports of eligible studies from all the literature in PubMed®, EMBASE®, PsycINFO®, CINAHL®, and the Cochrane Library through August Articles in the PubMed database dated back to 1966.
Only studies conducted in the United States or other high-income countries were included. Studies of children that tested interventions of diet, physical activity, or any combination of these in any setting or combinations of settings (e.g., school, home, primary care, childcare, consumer health informatics) were included. The interventions had to be tested over at least 1 year, with the exception of school-based studies or studies in other settings with a school component, which were required to be 6 months in duration. The effects of the interventions on outcomes related to body weight or body composition (e.g., body mass index [BMI], weight, BMI-z score [measure of relative weight adjusted for age and sex], waist circumference, percent body fat, skinfold thickness, prevalence of obesity or overweight); clinical outcomes related to obesity (e.g., blood pressure, blood lipids); behavioral outcomes related to energy balance (e.g., dietary intake, physical activity, sedentary behaviors); and adverse effects of interventions were evaluated.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at

2. Outline of Material
Introduction to childhood obesity and the various programs designed to prevent it
Systematic review methods
The clinical questions addressed by the comparative effectiveness review
Results of the review and evidence-based conclusions about the relative effectiveness of currently available programs to prevent childhood obesity
Gaps in knowledge and future research needs
What to discuss with patients and their caregivers
Outline of Material
The material in this presentation covers the results and conclusions from a systematic comparative effectiveness review entitled Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. It begins with an introduction to obesity and overweight and the types of programs currently available for their prevention. It also covers methods used to plan and execute the systematic review, clinically important questions the review sought to answer, results of the review, evidence-based conclusions about the relative effectiveness and safety of the currently available obesity or overweight prevention programs, gaps in knowledge, and the future research needs uncovered by the systematic review.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

3. Background: Prevalence of Childhood Obesity
Childhood overweight and obesity are highly prevalent in the United States, affecting one-third of children and adolescents.
Since 1980, the rates of obesity have tripled for children aged 2 to 19 years.
The risk of obesity is higher among minority and low- income populations.
Background: Prevalence of Childhood Obesity
Childhood obesity has become a major public health epidemic in the United States. At present, more than one-third of American children and adolescents are overweight or obese, reflecting a nearly threefold increase in obesity prevalence since 1980.
Data from the 2009–2010 U.S. National Health and Nutrition Examination Survey indicated that among children and adolescents aged 2 through 19 years, 16.9 percent were obese and 31.8 percent were either overweight or obese. Since 1980, the prevalence of obesity has tripled among children aged 2 to 19 years. The prevalence of obesity increased from 5.0 to 12.1 percent among children aged 2 through 5 years, 6.5 to 18.0 percent among children aged 6 through 11 years, and 5.0 to 18.4 percent among adolescents aged 12 through 19 years between 1976–1980 and 2009–2010.
Some minority groups—such as African Americans, Hispanics, and Native Americans and low-income groups—are at higher risk of obesity.
References
Ogden CL, Carroll MD, Kit BK, et al. Prevalence of obesity and trends in body mass index among US children and adolescents, 1999–2010. JAMA Feb;307(5): PMID:
Wang Y, Beydoun M. The obesity epidemic in the United States—gender, age, socioeconomic, racial/ethnic, and geographic characteristics: a systematic review and meta-regression analysis. Epidemiol Rev. 2007;29:6-28. PMID:
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Ogden CL, Carroll MD, Kit BK, et al. JAMA. 2012;307(5): PMID:
Wang Y, Beydoun M. Epidemiol Rev. 2007;29:6-28. PMID:
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

4. Background: Health Consequences of Childhood Obesity
Overweight children and adolescents are at greater risk for health problems when compared with their normal-weight peers and are more likely to become obese adults.
Obese children and adolescents are more likely to have serious illnesses such as type 2 diabetes, hypertension, high cholesterol, stroke, heart disease, nonalcoholic fatty liver disease, certain types of cancer, and arthritis.
Other reported health consequences of childhood obesity include eating disorders and mental health issues such as depression and low self-esteem
Background: Health Consequences of Childhood Obesity
Childhood obesity has many intermediate-term and long-term health consequences. Overweight children and adolescents are at greater risk for health problems when compared with their normal-weight peers. Overweight children and adolescents are more likely to become obese adults. Obese children and adolescents are more likely to have adverse health conditions, such as poor cardiovascular, metabolic, and psychosocial outcomes. Obesity is a risk factor for many chronic conditions, including type 2 diabetes, hypertension, high cholesterol, stroke, heart disease, nonalcoholic fatty liver disease, certain types of cancer, and arthritis. It is estimated that excess weight causes 70 percent of diabetes in the United States. Obesity increases mortality as well. The other reported health risks of childhood obesity include eating disorders (such as bulimia nervosa, restrictive eating, binging, purging, generalized food preoccupation, and distorted body image) and mental health issues (such as depression and low self-esteem).
References
Centers for Disease Control and Prevention. Childhood Overweight and Obesity.
Reilly JJ, Kelly J. Long-term impact of overweight and obesity in childhood and adolescence on morbidity and premature mortality in adulthood: systematic review. Int J Obes (Lond) Jul;35(7): PMID:
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Centers for Disease Control and Prevention. Available at
Reilly JJ, Kelly J. Int J Obes (Lond) Jul;35(7): PMID:
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

5. Background: Factors Contributing to Childhood Obesity
Many factors interact to contribute to obesogenic environments and affect children’s weight. These include:
Genetic and individual factors
Home influences
The school environment
Factors in the local community
Policies implemented at the regional and national levels
Background: Factors Contributing to Childhood Obesity
Obesity is the result of many biological, behavioral, social, environmental, and economic factors and the complex interactions between them that promote a positive energy balance. At present, how these factors contribute to the disparities in obesity prevalence between population groups in the United States remains poorly understood. Nevertheless, a growing body of research suggests that many factors interact to promote obesity, including individual factors (e.g., genetics, nutrition knowledge and attitude, body weight image), home influences (e.g., parenting, food served at home, parental weight status), school factors (e.g., nutrition service, curriculum including physical activity, annual measure of body mass index), factors in the local community (e.g., presence of sidewalks, parks, safety from traffic, crime rate), and those at the regional and national levels (e.g., economic factors such as food prices, food assistance programs). These factors contribute to obesogenic environments and affect children’s weight.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

6. Background: Preventing Childhood Obesity
Obesity is difficult to treat, and prevention of childhood obesity has been identified as a key to fight the growing obesity epidemic.
Leading health organizations, including the World Health Organization and an Institute of Medicine expert panel, have recommended comprehensive interventions to fight obesity.
The main goal of most childhood obesity prevention interventions is to prevent children who are not overweight from becoming overweight or obese.
Interventions designed for obesity prevention may also help overweight or obese children lose excess weight or stabilize their weight.
Background: Preventing Childhood Obesity
Obesity is difficult to treat, and prevention of childhood obesity has been identified as a key to fight the growing global obesity epidemic. A number of leading health organizations, including the World Health Organization and an Institute of Medicine expert panel, have recommended comprehensive interventions to prevent childhood obesity. The goal of obesity prevention interventions is to prevent children who are not overweight from becoming overweight or obese. These interventions may also help overweight or obese children lose or stabilize their weight.
References
Koplan JP, Liverman CT, Kraak VA, eds. Preventing Childhood Obesity: Health in the Balance. Washington, DC: The National Academies Press; Available at
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
World Health Organization. Global Strategy on Diet, Physical Activity and Health: What can be done to fight the childhood obesity epidemic?
Koplan JP, Liverman CT, Kraak VA, eds. Preventing Childhood Obesity: Health in the Balance.
Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No Available at
World Health Organization. en/index.html.

7. Background: Objectives of This Comparative Effectiveness Review
This review aimed to compare the effectiveness of obesity prevention programs for children and adolescents conducted in the United States and other high-income countries.
All studies of children that tested interventions of diet, physical activity, or any combination of these in any of the following settings were included in this review.
School
Home
Primary care clinic
Childcare center
Community setting
A combination of the above
The authors of this review also assessed consumer health informatics interventions.
Background: Objectives of This Comparative Effectiveness Review
The authors of this review aimed to compare the effectiveness of obesity prevention programs for children and adolescents conducted in the United States and other high-income countries. Studies that tested interventions of diet, physical activity, or a combination of these in children at school, at home, in a primary care clinic, in a childcare center, or in a community setting or a combination of these settings were included in the analysis. The authors also reviewed consumer health informatics interventions. Definitions of the various obesity prevention interventions are provided in the next slide.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

8. Setting of Intervention
Settings of Obesity Prevention Interventions Assessed in This Comparative Effectiveness Review (1 of 2)
Setting of Intervention
Definition
School-Based Interventions
These took place primarily in schools (e.g., change in quantity and nutritional quality of food served at school, increase in physical activity at school, promotion of walk-to-school days), although they might also have involved community (e.g., improving community parks, performing community service) or at-home activities (e.g., daily physical activity homework of about 10 minutes, preparing a healthy breakfast at home).
Home-Based Interventions
These took place in the child’s home (e.g., interventions to alter the foods purchased for home use, family fitness).
Primary Care-Based Interventions
These took place in the offices of a primary care practitioner, a clinic, or other health care entity delivering primary health care to children. They included advice to parents and/or caregivers to make changes at home (e.g., encouraging more than five daily servings of fruits and vegetables , limiting screen time to less than 2 hours per day, and promoting greater than 1 hour of physical activity per day).
Settings of Obesity Prevention Interventions Assessed in This Comparative Effectiveness Review (1 of 2)
The table in this slide lists the settings of obesity prevention interventions assessed in the review. Assessed interventions include school-based interventions, home-based interventions, and primary care-based interventions.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

9. Setting of Intervention
Settings of Obesity Prevention Interventions Assessed in This Comparative Effectiveness Review (2 of 2)
Setting of Intervention
Definition
Childcare Center-Based Interventions
These took place in settings where children received nonparental/ noncustodial care, generally outside the home (e.g., offering fruits and vegetables throughout the day, enhancing physical activity, designing exercise programs that improve pleasure of movement).
Community-Based and Environment-Level Interventions
These were delivered by enforcing policies or legislation (e.g., regulations on food retailing and distribution) or by changes to the built environment (e.g., restaurants, farmers’ markets, recreation facilities). Additionally, these interventions involved interaction with the community (such as the YMCA or church groups).
Consumer Health Informatics-Based Interventions
Consumer health informatics are technologies that deliver interventions and information indirectly (as opposed to in person) to patients or individuals in the community. These interventions might include Web-based, phone-based, and video-based programs, games, and information storehouses.
Settings of Obesity Prevention Interventions Assessed in This Comparative Effectiveness Review (2 of 2)
The table in this slide lists additional settings of obesity prevention interventions assessed in the review. Assessed interventions include childcare center-based interventions, community-based and environment-level interventions, and consumer health informatics-based interventions.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

10. Agency for Healthcare Research and Quality (AHRQ) Comparative Effectiveness Review (CER) Development
Topics are nominated through a public process, which includes submissions from health care professionals, professional organizations, the private sector, policymakers, members of the public, and others.
A systematic review of all relevant clinical studies is conducted by independent researchers, funded by AHRQ, to synthesize the evidence in a report summarizing what is known and not known about the select clinical issue. The research questions and the results of the report are subject to expert input, peer review, and public comment.
The results of these reviews are summarized into Clinician Research Summaries and Consumer Research Summaries for use in decisionmaking and in discussions with patients and/or caregivers.
The Research Summaries and the full report, with references for included and excluded studies, are available at child-obesity-prevention.cfm.
Agency for Healthcare Research and Quality (AHRQ) Comparative Effectiveness Review (CER) Development
Topics are nominated through a public process, which includes submissions from health care professionals, professional organizations, the private sector, policymakers, members of the public, and others. A systematic review of all relevant clinical studies is conducted by independent researchers, funded by AHRQ, to synthesize the evidence in a report summarizing what is known and not known about the select clinical issue. The research questions and the results of the report are subject to expert input, peer review, and public comment. The results of these reviews are summarized into Clinician Research Summaries and Consumer Research Summaries for use in decisionmaking and in discussions with patients and/or caregivers. The Research Summaries and the full report, with references for included and excluded studies, are available at
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

11. Clinical Questions Addressed by This Comparative Effectiveness Review (1 of 2)
Key Question 1. What is the comparative effectiveness of school- based interventions for the prevention of obesity or overweight in children?
Key Question 2. What is the comparative effectiveness of home- based interventions for the prevention of obesity or overweight in children?
Key Question 3. What is the comparative effectiveness of primary care-based interventions for the prevention of obesity or overweight in children?
Key Question 4. What is the comparative effectiveness of childcare setting-based interventions for the prevention of obesity or overweight in children?
Clinical Questions Addressed by This Comparative Effectiveness Review (1 of 2)
This comparative effectiveness review attempted to address seven key questions. Key Questions (KQ) 1 through 4 are listed on this slide.
KQ 1. What is the comparative effectiveness of school-based interventions for the prevention of obesity or overweight in children?
One hundred and four studies described in 110 articles addressed KQ 1.
KQ 2. What is the comparative effectiveness of home-based interventions for the prevention of obesity or overweight in children?
Six studies addressed KQ 2.
KQ 3. What is the comparative effectiveness of primary care-based interventions for the prevention of obesity or overweight in children?
One study addressed KQ 3.
KQ 4. What is the comparative effectiveness of childcare setting-based interventions for the prevention of obesity or overweight in children?
Four studies described in five articles addressed KQ 4.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

12. Clinical Questions Addressed by This Comparative Effectiveness Review (2 of 2)
Key Question 5. What is the comparative effectiveness of community-based or environment-level interventions for the prevention of obesity or overweight in children?
Key Question 6. What is the comparative effectiveness of consumer health informatics applications for the prevention of obesity or overweight in children?
Key Question 7. What is the comparative effectiveness of multisetting interventions for the prevention of obesity or overweight in children?
Key Question 7 was addressed as part of the other six Key Questions.
Clinical Questions Addressed by This Comparative Effectiveness Review (2 of 2)
This comparative effectiveness review attempted to address seven key questions. Key Questions (KQ) 5, 6, and 7 are listed on this slide:
KQ 5. What is the comparative effectiveness of community-based or environment-level interventions for the prevention of obesity or overweight in children? Nine studies addressed KQ 5.
KQ 6. What is the comparative effectiveness of consumer health informatics applications for the prevention of obesity or overweight in children?
No studies directly addressed KQ 6.
KQ 7: What is the comparative effectiveness of multisetting interventions for the prevention of obesity or overweight in children? KQ 7 was addressed as part of the other six KQs.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

13. Rating the Strength of Evidence From the Comparative Effectiveness Review
The strength of evidence was classified into four broad categories:
High
Further research is very unlikely to change the confidence in the estimate of effect.
Moderate
Further research may change the confidence in the estimate of effect and may change the estimate.
Low
Further research is likely to change the confidence in the estimate of effect and is likely to change the estimate.
Insufficient
Evidence either is unavailable or does not permit a conclusion.
Rating the Strength of Evidence From the Comparative Effectiveness Review
Throughout this slide set, strength-of-evidence ratings are assigned to findings of the report. Strength of evidence is typically assigned to reviews of medical treatments or interventions after assessing four domains: risk of bias, consistency, directness, and precision. Although these categories were developed to assess the strength of treatment studies, the domains also apply to studies of prevention, prevalence, and screening. Available evidence for each Key Question (KQ) was assessed for each of these four domains; the domains were combined qualitatively to develop the strength of evidence for each KQ.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

14. Evidence for the Benefits of School-Based Interventions in Preventing Obesity or Overweight in Children (1 of 3)
School-Based Interventions Only
School-based diet or physical activity interventions prevent obesity or overweight in children. ˜˜™
Strength of Evidence: Moderate
„„School-based combination diet and physical activity interventions prevent obesity or overweight in children.
Strength of Evidence: Insufficient
School-Based Interventions With a Home Component
Physical activity interventions within school-based settings with a home component prevent obesity or overweight in children.
Strength of Evidence: High
Combined diet and physical activity interventions in a school-based setting with a home component prevent obesity or overweight in children.
Evidence for the Benefits of School-Based Interventions in Preventing Obesity or Overweight in Children (1 of 3)
The strength of evidence is moderate that school-based diet or physical activity interventions prevent obesity or overweight in children. Two randomized controlled trials, described in three articles, evaluated the effects of diet interventions on weight-related outcomes and showed a decrease in body mass index (BMI) or BMI Z-score measures over a period of at least 1 year. These studies were specifically designed to prevent weight gain and focused on promoting a healthy diet and reducing the consumption of carbonated drinks. Fifteen studies reported on the effects of physical activity interventions in school on weight-related outcomes. Physical activity interventions had an impact on BMI, waist circumference in girls, skinfold thickness at 52 weeks, and percentage of body fat in children. These studies were designed to prevent weight gain, reduce sedentary screen-viewing time, promote participation in physical activity, and improve fundamental movement skills among children. None of these studies reported on adverse events (harms).
The strength of evidence is insufficient to determine if school-based combination diet and physical activity interventions prevent obesity or overweight in children. Thirty-seven studies assessed the effect of a combined diet and physical activity intervention on weight-related outcomes. Combination interventions show low-strength evidence that they are effective at reducing BMI, BMI Z-score, prevalence of obesity and overweight, percentage of body fat, waist circumference, and skinfold thickness. Studies reporting on these outcomes were designed to affect weight gain and included intensive classroom physical activity lessons led by trained teachers, moderate to vigorous physical activity sessions, nutrition education materials, and promoting and providing a healthy diet. The intervention studies with significant impact had a duration of 52 to 156 weeks.
There is high-strength evidence that physical activity interventions in a school-based setting with a home component prevent obesity or overweight in children. Two studies focused exclusively on physical activity interventions. These studies were multicomponent physical activity programs that included both an educational and environmental approach to physical activity. A third study focused on the reduction of sedentary behavior associated with television, videotape, and videogame use. All studies demonstrated some improvements in BMI, waist circumference, and skinfold thickness due to the intervention. The studies did not report any adverse effects. The results of these studies suggest that interventions aimed at either increasing physical activity or reducing sedentary behavior can be effective at preventing obesity.
There is moderate-strength evidence that combined diet and physical activity interventions prevent overweight and obesity. Overall, the findings suggest that combined diet and physical activity interventions have favorable effects on weight outcomes. Seventeen studies reported on BMI (kg/m2); 14 of these studies reported changes in favor of the intervention. A meta-analysis showed that the overall weighted mean difference in BMI was kg/m2 (95-percent confidence interval -0.57, 0.23; p = 0.407), which favored the intervention but was not statistically significant. Three studies reported on BMI percentile; two of these studies were statistically significant in favor of the intervention. Three studies reported on the prevalence of overweight or obesity; all three showed a significant effect in favor of the intervention.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

15. Meta-analysis of Change in Body Mass Index Between the Control Group and Combined Diet and Physical Activity Interventions in a School Setting With a Home Component
Burke, 1998
Dzewaltowski, 2010
Siegrist, 2011
Story, 2012
Hatzis, 2010
Mihas, 2010
Llargues, 2011
Overall (I-squared = 99.1%, p = 0.000)
0.00 (-0.16, 0.16) 12.49
0.10 (-0.05, 0.25) 12.51
-0.10 (-0.18, -0.02) 12.67
0.10 (0.06, 0.14) 12.71
0.34 (0.15, 0.53) 12.36
1.00 (0.80, 1.20) 12.34
-1.20 (-1.32, -1.08) 12.59
-1.60 (-1.80, -1.40) 12.33
-0.17 (-0.57, 0.23)
NOTE: Weights are from random effects analysis
Intervention
Control
-1.9
1.4
Study ID
WMD
(95% CI)
% Weight
WMD = weighted mean difference
Meta-analysis of Change in Body Mass Index Between the Control Group and Combined Diet and Physical Activity Interventions in a School Setting With a Home Component
The figure on this slide shows the Forest plot of the meta-analysis of change in body mass index (BMI) between the control group and combined diet and physical activity-only interventions in a school setting with a home component. The meta-analysis was based on 7 out of 17 studies that measured BMI and showed that the overall weighted mean difference in BMI was kg/m2 (95-percent confidence interval -0.57, 0.23; p = 0.407), which favored the intervention but was not statistically significant.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

16. Evidence for the Benefits of School-Based Interventions in Preventing Obesity or Overweight in Children (2 of 3)
School-Based Interventions With a Community Component
Combined diet and physical activity interventions in a school-community setting prevent obesity or overweight in children. ˜˜™
Strength of Evidence: Moderate
School-Based Interventions With Home and Community Components
Combined diet and physical activity interventions in a school-home-community setting prevent obesity or overweight in children. ˜˜™
Strength of Evidence: High
Evidence for the Benefits of School-Based Interventions in Preventing Obesity or Overweight in Children (2 of 3)
The strength of evidence is moderate that diet with physical activity impacts body mass index (BMI) or BMI Z-score in a school-based setting with a community component, as two of the four studies with moderate risk of bias showed a favorable effect. The majority of these studies specifically targeted weight gain prevention. The focus of the interventions varied greatly—education, structural changes to promote diet changes and physical activity, or both. One reason for the nonsignificant effect on weight outcomes seen in some studies might have been that the sample sizes were small.
The strength of evidence is high that combined diet and physical activity interventions in a school-based setting with home and community components prevent obesity or overweight. Five studies reported on BMI Z-score. All reported changes in BMI Z-score favored the intervention. Two studies were significant, and the remaining three reported a nonsignificant change. Three studies reported on BMI. Two reported a nonsignificant change in BMI in favor of the intervention. Another preintervention-postintervention study found a significant rise in BMI in followup measures when compared with baseline in favor of the intervention. Overall, studies of a combination of diet and physical activity interventions generally showed significant improvements in weight outcomes. Most interventions focused on education as well as structural changes to promote a healthy diet and increased physical activity. Many of the interventions did not specifically target obesity prevention.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

17. Evidence for the Benefits of School-Based Interventions in Preventing Obesity or Overweight in Children (3 of 3)
School-Based Interventions With a Consumer Health Informatics Component
Evidence is insufficient to determine if physical activity or combined diet and physical activity interventions in a school setting with a consumer health informatics component prevent childhood obesity or overweight.˜˜™
Strength of Evidence: Insufficient
Evidence for the Benefits of School-Based Interventions in Preventing Obesity or Overweight in Children (3 of 3)
The strength of evidence is insufficient that school-based physical activity interventions or combined diet and physical activity interventions with a consumer health informatics component prevent obesity or overweight in children. None of the four identified studies showed a significant intervention effect on weight outcomes. The body of evidence was graded as insufficient because it lacked precision and included studies that had a moderate risk of bias.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

18. Home-Based Interventions Only
Evidence for the Benefits of Home-Based or Childcare Center-Based Interventions in Preventing Obesity or Overweight in Children
Home-Based Interventions Only
Home-based combination (diet and physical activity) interventions prevent obesity or overweight in children.
Strength of Evidence: Low
Childcare Center-Based Interventions Only
Combined diet and physical activity interventions in a childcare center setting showed no beneficial effect on childhood obesity or overweight prevention. ˜˜™
Evidence for the Benefits of Home-Based or Childcare Center-Based Interventions in Preventing Obesity or Overweight in Children
The strength of evidence is low that home-based combination diet and physical activity interventions prevent overweight or obesity in children. Three combined diet and physical activity intervention trials did not detect a significant beneficial intervention effect on body mass index (BMI), BMI Z-score, or prevalence of overweight. Combined interventions in this setting had a beneficial effect on fruit and vegetable intake. However, no conclusions can be made regarding their effect on other dietary, physical activity, or sedentary behaviors. The strength of evidence is insufficient to determine if diet and physical activity interventions in a home-based setting with a school, community, and/or primary care component prevent obesity or overweight.
The strength of evidence is low that childcare center-based combination diet and physical activity interventions prevent overweight or obesity in children. Across all three combined diet and physical activity intervention studies in the childcare center-based settings, there were no significant between-group differences with respect to BMI Z-score, BMI, and prevalence of obesity and overweight. One out of the three combined diet and physical activity intervention studies found a significant increase in fruit and vegetable intake. However, none of these studies found a significant intervention effect on physical activity, total fat intake, or fiber intake. The small sample size and poor quality of these studies may have contributed to the attenuated effect of the intervention on weight outcomes. High-quality studies with a larger sample size are needed to further evaluate the impact of the intervention.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

19. Community-Based Interventions With a School Component
Evidence for the Benefits of Community-Based or Primary Care–Based Interventions in Preventing Obesity or Overweight in Children
Community-Based Interventions With a School Component
Combined diet and physical activity interventions in a community setting with some school involvement prevent childhood obesity or overweight.˜˜™
Strength of Evidence: Moderate
Primary Care-Based Interventions Only
Evidence is insufficient to determine if combined diet and physical activity interventions in a primary care setting prevent obesity or overweight in children.˜˜™
Strength of Evidence: Insufficient
This does not mean that interventions do not work in the primary care setting, but more research is needed.
Evidence for the Benefits of Community-Based or Primary Care-Based Interventions in Preventing Obesity or Overweight in Children
There was moderate-strength evidence that combined diet and physical activity interventions in a community-based setting with a school component prevent obesity and overweight in children. The results from outcome measures from two community/school-based studies reporting on combined interventions support these conclusions. One study reported on the body mass index (BMI) Z-score and showed a significant decrease in it. Two studies reported on BMI, and one showed a significant decrease in it. These interventions focused on education and environmental changes promoting a healthy diet and physical activity.
No meaningful conclusions could be made regarding the effectiveness of a combined diet and physical activity intervention on obesity or overweight in a primary care setting. The strength of evidence for this finding was rated insufficient based on the results of a single-arm study of a combined diet and physical activity intervention. This study evaluated the effect of an intervention on prevalence of overweight and obesity, both of which increased during the intervention. The study did not statistically analyze this change in prevalence of overweight and obesity. The study reported on the percentage of parents reporting diet, physical activity, and screen-viewing time changes based on surveys conducted during the intervention. However, because the baseline values for these outcomes were not reported, we could not fully assess the intervention effect. Although the study’s overall goal was to reduce the risk of childhood obesity, the intervention primarily aimed to achieve this goal through direct improvement of clinical decision support and family management of risk behaviors. Consequently, the intervention effect on weight outcomes may have been attenuated. Additional factors that may have limited the effectiveness of the intervention include the lack of randomization, the lack of a comparison group, and failure to reassess weight outcomes after completion of the intervention.
The lack of sufficient evidence in the primary care setting does not mean that interventions do not work in this setting but that more research is needed.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

20. Conclusions (1 of 2)
School-based programs involving dietary or physical activity interventions are effective in preventing childhood obesity.
Combining a home or community component with a school-based program also works.
The magnitude of effects appears to be modest, although the heterogeneity in study interventions, outcomes, and duration make it difficult to estimate a precise effect size.
Conclusions (1 of 2)
There is moderate-strength evidence that school-based diet or physical activity interventions are effective in preventing childhood obesity. Two randomized controlled trials evaluated the effects of diet interventions on weight-related outcomes and showed a decrease in body mass index (BMI) or BMI Z-score measures over a period of at least 1 year. Fifteen studies reported on the effects of school-based physical activity interventions on weight-related outcomes. Physical activity interventions had an impact on BMI, waist circumference in girls, skinfold thickness at 52 weeks, and percentage of body fat in children.
Combining a home or community component with a school-based program also works.
There is high-strength evidence that physical activity interventions in a school-based setting with a home component prevent obesity or overweight in children. All three studies evaluating physical activity (multicomponent physical activity or a reduction of sedentary behavior) demonstrated some improvements in BMI, waist circumference, and skinfold thickness.
There is moderate-strength evidence that combined diet and physical activity interventions in a school-based setting with a home component prevent overweight and obesity. Overall, the findings suggest that combined diet and physical activity interventions have favorable effects on weight outcomes including BMI, BMI percentile, and prevalence of overweight or obesity.
The strength of evidence is moderate that diet with physical activity in a school-based setting with a community component impacts BMI or BMI Z-score. Two of the four studies with moderate risk of bias showed a favorable effect.
The strength of evidence is high that combined diet and physical activity interventions in a school-based setting with home and community components prevent obesity or overweight.
There were many differences across studies in terms of countries, settings, design, sample size, sample characteristics, specific intervention approaches, primary measures that assess intervention effects, length of followup, and statistical analysis approaches. Such variability made it difficult to conduct meta-analyses for most of the various intervention studies. For those studies and outcomes where a meta-analysis was possible, the magnitude of effects appear to be modest.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

21. Conclusions (2 of 2)
Evidence is limited regarding the effectiveness of interventions in other settings including those in primary care.
This does not mean that such interventions do not work but that more research is needed.
Conclusions (2 of 2)
The evidence on the effectiveness of interventions primarily implemented in other settings such as the home, primary care clinics, childcare centers, or the community is largely low or insufficient. This does not mean that such interventions do not work but that more research is needed.
More research is needed to test interventions in other settings, particularly to test the impact of policy changes (e.g., regulations on food retailing and distribution), changes to the built environment (e.g., restaurants, farmers’ markets, recreation facilities), and consumer health informatics strategies.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

22. Gaps in Knowledge (1 of 2)
Several gaps in knowledge were identified in the evidence base reviewed for this report:
„„A lack of sufficient information on the effectiveness of the following types of obesity and overweight prevention interventions
Interventions tested in the primary care or childcare settings
††Environment-based and policy-based interventions (e.g., agriculture policies and regulations on food retailing and distribution)
Consumer health informatics interventions
Gaps in Knowledge (1 of 2)
Several gaps in knowledge were identified in the evidence base reviewed for this report:
Very few studies took place in clinical settings such as primary care. Primary health care providers could play an important role in childhood obesity prevention and treatment by providing healthy eating and exercise guidelines and by regularly monitoring body weight.
Studies that test environment-based and policy-based interventions were limited. Although environment is a critical area for obesity prevention, very few studies have tested such interventions. In addition, there is scant evidence on the impact of regional or national policies on childhood obesity prevention, including agriculture policies and regulations on food retailing and distribution.
Additionally, there was a paucity of information on the effect of consumer health informatics interventions on childhood obesity prevention. Only a few studies used consumer health informatics tools such as social marketing to deliver messages on nutrition, physical activity, and health. Studies can integrate this approach with other intervention components to promote desirable lifestyle changes.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

23. Gaps in Knowledge (2 of 2)
The need for an improved understanding of the contexts and challenges associated with implementing prevention programs in different settings
A paucity of information on the effects of various interventions in preventing childhood obesity in populations stratified by sex, age, ethnicity, demographics, or socioeconomic status
Limited information on the effectiveness of obesity prevention programs in adolescents
Gaps in Knowledge (2 of 2)
There is a need to understand the contexts and challenges associated with implementing prevention programs in different settings. For example, to conduct a childhood obesity prevention program in a community setting, researchers often need to work with the local community and its key stakeholders, which usually requires considerable effort and resources. Such demand may help explain the small number of intervention studies conducted in nonschool settings. Researchers should report these contextual factors to help decisionmakers get a better idea of the applicability of a specific intervention program to their own community.
Most of the studies we reviewed did not report results by subgroups stratified by sex, age, race/ethnicity, or socioeconomic status. Subgroup analysis is necessary, as the effect size of a specific intervention may be small due to the heterogeneity of intervention effects among different subgroups. It is essential that future research generates information about important subgroups—such as populations stratified by sex, age, race/ethnicity, or socioeconomic status—to test whether different groups respond differently to the same intervention and help tailor future interventions to maximize their benefits.
Studies that evaluated the effectiveness of obesity prevention programs in adolescents were limited. More research is needed to determine the effectiveness of obesity prevention programs in adolescents; studies have found that obesity in older children is more predictive of obesity during adulthood than is obesity in younger children.
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

24. What To Discuss With Your Patients and Their Caregivers (1 of 2)
That clinicians are concerned about childhood obesity and the welfare of their patients
„The patient’s body mass index and how to diagnose overweight/ obesity in children
„„The possible factors contributing to overweight and obesity in children, including less physical activity, more sedentary/screen time, increased empty and liquid calories in the diet, and inappropriate use of food rewards or eating when not hungry
„„What constitutes an appropriate serving size
„„The importance of monitoring total daily caloric intake as opposed to total daily food intake
„„Important things that can be done at home to keep children at a healthy weight
What To Discuss With Your Patients and Their Caregivers (1 of 2)
Issues you should discuss with your patients and their parents/caregivers regarding interventions for preventing obesity and overweight in children include:
That clinicians are concerned about childhood obesity and the welfare of their patients
The patient’s body mass index and how to diagnose overweight/obesity in children
The possible factors contributing to overweight and obesity in children, including less physical activity, more sedentary/screen time, increased empty and liquid calories in the diet, and inappropriate use of food rewards or eating when not hungry
What constitutes an appropriate serving size
The importance of monitoring total daily caloric intake as opposed to total daily food intake
Important things that can be done at home to keep children at a healthy weight
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at

25. What To Discuss With Your Patients and Their Caregivers (2 of 2)
The potential health consequences of overweight and obesity in children
„„The relative effectiveness of the various interventions in preventing overweight and obesity
„„The programs and resources that help children maintain a healthy weight that are available at school or in the community
If a list of such resources could not be obtained, encourage parents and caregivers to explore schools, school district offices, and community centers for the available resources.
„„What can be done if healthy food or safe locations for physical activity are not easily accessible to patients and their families
What To Discuss With Your Patients and Their Caregivers (2 of 2)
Issues you should discuss with your patients and their parents/caregivers regarding interventions for preventing obesity and overweight in children include:
The potential health consequences of overweight and obesity in children
The relative effectiveness of the various interventions in preventing overweight and obesity
The programs and resources that help children maintain a healthy weight that are available at school or in the community
If a list of such resources could not be obtained, encourage parents and caregivers to explore schools, school district offices, and community centers for the available resources.
What can be done if healthy food or safe locations for physical activity are not easily accessible to patients and their families
Reference
Wang Y, Wu Y, Wilson RF, et al. Childhood Obesity Prevention Programs: Comparative Effectiveness Review and Meta-Analysis. Comparative Effectiveness Review No. 115 (Prepared by the Johns Hopkins University Evidence-based Practice Center under Contract No I). AHRQ Publication No. 13-EHC081-EF. Rockville, MD: Agency for Healthcare Research and Quality; June Available at
Wang Y, Wu Y, Wilson RF, et al. AHRQ Comparative Effectiveness Review No. 115.
Available at