Childhood obesity prevention through a community-based cluster randomized controlled physical activity intervention among schools in china: the health legacy project of the 2nd world summer youth olympic Games (YOG-Obesity study)

Childhood obesity prevention trials: A systematic review and meta-analysis on trial design and the impact of type 1 error

Effect sizes from previously reported trials are often used to determine the meaningful change in weight in childhood obesity prevention interventions because information on clinically meaningful differences is lacking. Estimates from previous trials may be influenced by statistical significance; therefore, it is important that they have a low risk of type 1 error. A systematic review and meta-analysis were conducted to report on the design of child obesity prevention randomized controlled trials and effectiveness according to risk of type 1 error. Eighty-four randomized controlled trials were identified. A large range of assumptions were applied in the sample size calculations. The most common primary outcome was BMI, with detectable effect size differences used in sample size calculations ranging from 0.25 kg/m2 (followed up at 2 years) to 1.1 kg/m2 (at 9 months) and BMI z-score ranging from 0.1 (at 4 years) to 0.67 (at 3 years). There was no consistent relationship between low risk of type 1 error and reports of higher or lower effectiveness. Further clarity of the size of a meaningful difference in weight in childhood obesity prevention trials is required to support evaluation design and decision-making for intervention and policy. Type 1 error risk does not appear to impact effect sizes in a consistent direction.

Interventions to prevent obesity in children aged 5 to 11 years old

BACKGROUND

Prevention of obesity in children is an international public health priority given the prevalence of the condition (and its significant impact on health, development and well-being). Interventions that aim to prevent obesity involve behavioural change strategies that promote healthy eating or 'activity' levels (physical activity, sedentary behaviour and/or sleep) or both, and work by reducing energy intake and/or increasing energy expenditure, respectively. There is uncertainty over which approaches are more effective and numerous new studies have been published over the last five years, since the previous version of this Cochrane review.

OBJECTIVES

To assess the effects of interventions that aim to prevent obesity in children by modifying dietary intake or 'activity' levels, or a combination of both, on changes in BMI, zBMI score and serious adverse events.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was February 2023.

SELECTION CRITERIA

Randomised controlled trials in children (mean age 5 years and above but less than 12 years), comparing diet or 'activity' interventions (or both) to prevent obesity with no intervention, usual care, or with another eligible intervention, in any setting. Studies had to measure outcomes at a minimum of 12 weeks post baseline. We excluded interventions designed primarily to improve sporting performance.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our outcomes were body mass index (BMI), zBMI score and serious adverse events, assessed at short- (12 weeks to < 9 months from baseline), medium- (9 months to < 15 months) and long-term (≥ 15 months) follow-up. We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

This review includes 172 studies (189,707 participants); 149 studies (160,267 participants) were included in meta-analyses. One hundred forty-six studies were based in high-income countries. The main setting for intervention delivery was schools (111 studies), followed by the community (15 studies), the home (eight studies) and a clinical setting (seven studies); one intervention was conducted by telehealth and 31 studies were conducted in more than one setting. Eighty-six interventions were implemented for less than nine months; the shortest was conducted over one visit and the longest over four years. Non-industry funding was declared by 132 studies; 24 studies were funded in part or wholly by industry. Dietary interventions versus control Dietary interventions, compared with control, may have little to no effect on BMI at short-term follow-up (mean difference (MD) 0, 95% confidence interval (CI) -0.10 to 0.10; 5 studies, 2107 participants; low-certainty evidence) and at medium-term follow-up (MD -0.01, 95% CI -0.15 to 0.12; 9 studies, 6815 participants; low-certainty evidence) or zBMI at long-term follow-up (MD -0.05, 95% CI -0.10 to 0.01; 7 studies, 5285 participants; low-certainty evidence). Dietary interventions, compared with control, probably have little to no effect on BMI at long-term follow-up (MD -0.17, 95% CI -0.48 to 0.13; 2 studies, 945 participants; moderate-certainty evidence) and zBMI at short- or medium-term follow-up (MD -0.06, 95% CI -0.13 to 0.01; 8 studies, 3695 participants; MD -0.04, 95% CI -0.10 to 0.02; 9 studies, 7048 participants; moderate-certainty evidence). Five studies (1913 participants; very low-certainty evidence) reported data on serious adverse events: one reported serious adverse events (e.g. allergy, behavioural problems and abdominal discomfort) that may have occurred as a result of the intervention; four reported no effect. Activity interventions versus control Activity interventions, compared with control, may have little to no effect on BMI and zBMI at short-term or long-term follow-up (BMI short-term: MD -0.02, 95% CI -0.17 to 0.13; 14 studies, 4069 participants; zBMI short-term: MD -0.02, 95% CI -0.07 to 0.02; 6 studies, 3580 participants; low-certainty evidence; BMI long-term: MD -0.07, 95% CI -0.24 to 0.10; 8 studies, 8302 participants; zBMI long-term: MD -0.02, 95% CI -0.09 to 0.04; 6 studies, 6940 participants; low-certainty evidence). Activity interventions likely result in a slight reduction of BMI and zBMI at medium-term follow-up (BMI: MD -0.11, 95% CI -0.18 to -0.05; 16 studies, 21,286 participants; zBMI: MD -0.05, 95% CI -0.09 to -0.02; 13 studies, 20,600 participants; moderate-certainty evidence). Eleven studies (21,278 participants; low-certainty evidence) reported data on serious adverse events; one study reported two minor ankle sprains and one study reported the incident rate of adverse events (e.g. musculoskeletal injuries) that may have occurred as a result of the intervention; nine studies reported no effect. Dietary and activity interventions versus control Dietary and activity interventions, compared with control, may result in a slight reduction in BMI and zBMI at short-term follow-up (BMI: MD -0.11, 95% CI -0.21 to -0.01; 27 studies, 16,066 participants; zBMI: MD -0.03, 95% CI -0.06 to 0.00; 26 studies, 12,784 participants; low-certainty evidence) and likely result in a reduction of BMI and zBMI at medium-term follow-up (BMI: MD -0.11, 95% CI -0.21 to 0.00; 21 studies, 17,547 participants; zBMI: MD -0.05, 95% CI -0.07 to -0.02; 24 studies, 20,998 participants; moderate-certainty evidence). Dietary and activity interventions compared with control may result in little to no difference in BMI and zBMI at long-term follow-up (BMI: MD 0.03, 95% CI -0.11 to 0.16; 16 studies, 22,098 participants; zBMI: MD -0.02, 95% CI -0.06 to 0.01; 22 studies, 23,594 participants; low-certainty evidence). Nineteen studies (27,882 participants; low-certainty evidence) reported data on serious adverse events: four studies reported occurrence of serious adverse events (e.g. injuries, low levels of extreme dieting behaviour); 15 studies reported no effect. Heterogeneity was apparent in the results for all outcomes at the three follow-up times, which could not be explained by the main setting of the interventions (school, home, school and home, other), country income status (high-income versus non-high-income), participants' socioeconomic status (low versus mixed) and duration of the intervention. Most studies excluded children with a mental or physical disability.

AUTHORS' CONCLUSIONS

The body of evidence in this review demonstrates that a range of school-based 'activity' interventions, alone or in combination with dietary interventions, may have a modest beneficial effect on obesity in childhood at short- and medium-term, but not at long-term follow-up. Dietary interventions alone may result in little to no difference. Limited evidence of low quality was identified on the effect of dietary and/or activity interventions on severe adverse events and health inequalities; exploratory analyses of these data suggest no meaningful impact. We identified a dearth of evidence for home and community-based settings (e.g. delivered through local youth groups), for children living with disabilities and indicators of health inequities.

A scoping review of school-based anthropometric measurement

Though anthropometric measurement (AM) frequently occurs in school settings, it is not without risks to child wellbeing. The aim of this scoping review was to examine how AM in school settings takes place and is reported on to make recommendations on best practices. We identified and extracted data from 440 studies published since 2005 that conducted AM in school (pre-school through secondary/high school) settings. Privacy and sensitivity of AM were unclear in over 90% of studies. Thirty-one studies (7.0%) reported protecting student privacy, while nine (2.0%) reported public measurement. Only five studies reported sensitivity regarding AM (1.1%). Exactly who conducted AM was not specified in 201 studies (45.7%). Sixty-nine studies did not provide a weight status criteria citation (19.2%), and 10 used an incorrect citation (2.7%). In summary, serious shortcomings in the reporting of how AM is conducted and by whom, along with details concerning weight status classification, are evident. There is considerable room for improvement regarding the reporting of key methodological details. We propose best practices for AM in school settings, which also double as conditions that should be met before AM takes place in school settings.

Impact of School-Based Interventions on Pediatric Obesity: A Systematic Review

Childhood obesity is a global public health problem with significant implications for the health and well-being of children. The prevalence of childhood obesity is increasing every decade, making it a recognized public health concern. This systematic review aims to explore and evaluate the impact of school-based interventions on reducing pediatric obesity among school-aged children. A systematic review of literature according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 was conducted. Google Scholar, PubMed, and Cochrane were the databases used. After screening for bias, inclusion and exclusion criteria, and quality, 27 studies were included in the systematic review, and data were synthesized. The results show that physical activity reduces obesity and improves cardiovascular health. The nutritional change reduces the risk of obesity more than physical activity alone. When blended, the two provide the most benefits for participants. Motivation, self-efficacy, and behavioral change could help maintain the improvements. Schools should adopt a blend of physical activity and nutritional change to reduce prevent, reduce, and manage obesity.

Experiences, Perspectives, and Barriers to Physical Activity Parenting Practices for Chinese Early Adolescents

BACKGROUND

Parents play an important role in shaping youth's lifestyle behaviors. This study aimed to investigate physical activity parenting practices (PAPP) for Chinese early adolescents and compare reporting discrepancies between parents and adolescent boys and girls.

METHODS

Fifty-five adolescent-parent dyads participated in 16 paired focus group interviews, and an additional 122 dyads completed questionnaire surveys with open-ended questions. Participants were recruited from 3 public middle schools in Suzhou, China. Qualitative data were analyzed inductively using an open-coding scheme. Frequencies of codes were compared by parent-child role and adolescent gender using chi-square tests.

RESULTS

Eighteen types of PAPP were identified and grouped into 6 categories: goals/control, structure, parental physical activity participation, communication, support, and discipline. These PAPP were viewed as promotive, preventive, or ineffective. Participants had mixed opinions on the effects of 11 PAPP and identified parental, adolescent, and environmental barriers for parents to promote youth physical activity. Compared with parents, adolescents were more likely to value the effects of setting expectation, scheduling, and coparticipation as well as dislike pressuring, restriction, and punishment. Girls were more likely to favor coparticipation and were more sensitive about negative communication than boys. Parents paid more attention to environmental barriers, whereas adolescents, especially girls, focused more on personal issues.

CONCLUSIONS

Future studies need to address both positive and negative PAPP as well as perception discrepancies by child-parent role and adolescent gender to generate more evidence to promote parents as favorable socialization agents of youth physical activity.

School-Based Family-Oriented Health Interventions to Promote Physical Activity in Children and Adolescents: A Systematic Review

OBJECTIVE

This study aimed to systematically review and analyse intervention programs in a school context centred on the family, focused on increasing youths' physical activity.

DATA SOURCE

The research was carried out in the PubMed, Scopus and Web of Science databases.

STUDY INCLUSION CRITERIA

Studies were included if participants were children or adolescents, focusing on school-based intervention studies with parental involvement and physical activity, sedentary behaviour or physical fitness outcomes.

DATA EXTRACTION

The search was performed according to the PRISMA protocol. A total of 416 articles were identified. After being considered for eligibility and duplicates, 22 studies were identified as relevant for inclusion.

DATA SYNTHESIS

Sample and intervention characteristics, objective, the role of the family, outcomes measures, main findings regarding the outcomes and risk of bias.

RESULTS

Ten studies reported improvements in physical activity, 6 in sedentary behaviour and 9 in the components of physical fitness and/or skills related to healthy behaviours and lifestyles. Most of the interventions adopted a multidisciplinary and multi-component approach.

CONCLUSIONS

Most interventions employed a school's multidisciplinary/multi-component approach to promoting physical activity, nutrition, and general education for healthier lifestyle behaviours. The impact of school-based interventions involving families on youth's physical activity levels is still a relatively emerging theme. Further research is needed given the diversity of the intervention's characteristics and the disparity in the results' efficacy.

Barriers and facilitators of childhood obesity prevention policies: A systematic review and meta-synthesis

Objectives

Childhood obesity is one of the worldwide considerable public health challenges and many factors can play a role in its management. Therefore, this article examined the facilitators and barriers of childhood obesity prevention (COP) policies.

Methods

This systematic review of qualitative studies was conducted via a search of the SCOPUS, PubMed, and Google Scholar databases between 1 January 2010 and 11 February 2022 and examined factors that influence the implementation of COP policies at a community approach.

Results

The parents' reluctance to engage in COP activities, lack of sufficient knowledge, and financial problems were the most reported barriers at the individual level. In addition, the beliefs about COP at the sociocultural level and limited funding and resources, time limitations in stakeholders at the implementation level, and lack of policy support at the structural level were the most frequently reported barriers. Further, effective communication between stakeholders and parents and school staff at the sociocultural level and flexibility of the intervention, delivery of healthy food programs in schools, low-cost and appropriate resources, and the availability of appropriate facilities are the most frequently reported facilitators in the structural level.

Conclusion

Individual, sociocultural, and structural level-related barriers and facilitators influence the implementation of COP policies. Most of the barriers and facilitators in this systematic review were related to the structural level.

Outcome of structured health education intervention for obesity-risk reduction among junior high school students: Stratified cluster randomized controlled trial (RCT) in South India

BACKGROUND

Obesity has been identified as a serious global health concern whose prevalence doubles almost every 10 years. Health education regarding physical activity and healthy diet imparted to adolescents could prove to be fruitful in reducing obesity-risk. Objectives of this study were to evaluate the effect of health education intervention on knowledge, attitude, and practices (KAP) regarding obesity-risk reduction and to estimate the postinterventional change in body mass index (BMI) and total body fat (%) among adolescent school children in South India.

MATERIALS AND METHODS

Stratified cluster randomized controlled trial was carried out among 398 students recruited at baseline including 206 and 192 participants in intervention and control group respectively selected through simple random sampling from eligible government aided and private schools to assess KAP regarding physical activity and diet using pretested and validated questionnaire by making three school visits 6 months apart. Anthropometric measurements were recorded in first and third visit only, while health education intervention was given in first visit to intervention and third visit to control group after taking their responses on the questionnaire. Data were entered and analyzed using SPSS version 15.

RESULTS

Overall dropout rate was 13.5% with dropout in intervention and control group being 12.6% and 14.5% respectively, making 180 participants in intervention and 164 in control group available for analysis. Mean physical activity KAP score improved significantly from 16.19 ± 4.61 to 19.46 ± 10.07 in intervention group. Mean dietary KAP score also improved significantly from 21.38 ± 4.07 to 23.43 ± 4.53 in intervention group (p < 0.001). Mean BMI decreased significantly within intervention group (p < 0.001) as compared to control group (p = 0.908). Based on cut-off level for total body fat (%) to categorize obesity-risk among participants, statistically significant decline in proportions from 26.1% to 13.3% was observed in intervention group (p < 0.001).

CONCLUSION

Results depicted better KAP in intervention group than control group in all the three visits while it improved significantly within both groups. Hence, the health education was found to be effective in improving the overall KAP regarding modifiable risk factors of obesity among the study participants. Further studies to screen the adolescents for obesity-risk and successive health education sessions must be carried within schools in order to bring about change in knowledge, attitude, and practices regarding obesity-risk.

Interventions to prevent obesity in school-aged children 6-18 years: An update of a Cochrane systematic review and meta-analysis including studies from 2015-2021

BACKGROUND

Childhood obesity remains a global public health priority due to the enormous burden it generates. Recent surveillance data suggests there has been a sharp increase in the prevalence of childhood obesity during the COVID-19 pandemic. The Cochrane review of childhood obesity prevention interventions (0-18 years) updated to 2015 is the most rigorous and comprehensive review of randomised controlled trials (RCTs) on this topic. A burgeoning number of high quality studies have been published since that are yet to be synthesised.

METHODS

An update of the Cochrane systematic review was conducted to include RCT studies in school-aged children (6-18 years) published to 30 June 2021 that assessed effectiveness on child weight (PROSPERO registration: CRD42020218928). Available cost-effectiveness and adverse effect data were extracted. Intervention effects on body mass index (BMI) were synthesised in random effects meta-analyses by setting (school, after-school program, community, home), and meta-regression examined the association of study characteristics with intervention effect.

FINDINGS

Meta-analysis of 140 of 195 included studies (183,063 participants) found a very small positive effect on body mass index for school-based studies (SMD -0·03, 95%CI -0·06,-0·01; trials = 93; participants = 131,443; moderate certainty evidence) but not after-school programs, community or home-based studies. Subgroup analysis by age (6-12 years; 13-18 years) found no differential effects in any setting. Meta-regression found no associations between study characteristics (including setting, income level) and intervention effect. Ten of 53 studies assessing adverse effects reported presence of an adverse event. Insufficient data was available to draw conclusions on cost-effectiveness.

INTERPRETATION

This updated synthesis of obesity prevention interventions for children aged 6-18 years, found a small beneficial impact on child BMI for school-based obesity prevention interventions. A more comprehensive assessment of interventions is required to identify mechanisms of effective interventions to inform future obesity prevention public health policy, which may be particularly salient in for COVID-19 recovery planning.

FUNDING

This research was funded by the National Health and Medical Research Council (NHMRC), Australia (Application No APP1153479).

School Gardening, Cooking and Sports Participation Intervention to Improve Fruits and Vegetables Intake and Moderate-to-Vigorous Physical Activity among Chinese Children: Study Protocol for a Cluster Randomized Controlled Trial

Inadequate intake of fruits and vegetables (FV) and moderate-to-vigorous physical activity (MVPA) in children has become a global public health problem. Therefore, school-based gardening and cooking (SGC) and sports participation (SP) interventions may be effective in improving children's FV intake and MVPA. The aim of this study is to develop and evaluate the effectiveness of SGC and SP interventions on FV intake and MVPA among Chinese children. In this cluster randomized controlled trial study, 237 children in grades 4-5 from six public primary schools from Changsha, Hunan Province, China will be randomly assigned to: (1) a SGC and SP combined intervention group; (2) a SP intervention group; (3) a regular practice group. The intervention clusters will be implemented for a period of 6 months and follow up will be carried out after 12 months. The outcome will be collected using a combination of self-reported and objective measures. Primary outcomes will include children's FV intake and duration of MVPA per day, and secondary outcomes will included frequency and attitudes of FV intake and SP, in addition to other measures. Finally, a process evaluation will be used to analyze the facilitators and barriers to intervention implementation. Trial Registration: (Registration Number: ChiCTR2200064141).

Effectiveness of a Multifaceted Intervention for Prevention of Obesity in Primary School Children in China: A Cluster Randomized Clinical Trial

IMPORTANCE

A rapid nutritional transition has caused greater childhood obesity prevalence in many countries, but the repertoire of effective preventive interventions remains limited.

OBJECTIVE

To determine the effectiveness of a novel multifaceted intervention for obesity prevention in primary school children.

DESIGN, SETTING, AND PARTICIPANTS

A cluster randomized clinical trial was conducted during a single school year (from September 11, 2018, to June 30, 2019) across 3 socioeconomically distinct regions in China according to a prespecified trial protocol. Twenty-four schools were randomly allocated (1:1) to the intervention or the control group, with 1392 eligible children aged 8 to 10 years participating. Data from the intent-to-treat population were analyzed from October 1 to December 31, 2019.

INTERVENTIONS

A multifaceted intervention targeted both children (promoting healthy diet and physical activity) and their environment (engaging schools and families to support children's behavioral changes). The intervention was novel in its strengthening of family involvement with the assistance of a smartphone app. The control schools engaged in their usual practices.

MAIN OUTCOMES AND MEASURES

The primary outcome was the change in body mass index (BMI; calculated as weight in kilograms divided by height in square meters) from baseline to the end of the trial. Secondary outcomes included changes in adiposity outcomes (eg, BMI z score, prevalence of obesity), blood pressure, physical activity and dietary behaviors, obesity-related knowledge, and physical fitness. Generalized linear mixed models were used in the analyses.

RESULTS

Among the 1392 participants (mean [SD] age, 9.6 [0.4] years; 717 boys [51.5%]; mean [SD] BMI, 18.6 [3.7]), 1362 (97.8%) with follow-up data were included in the analyses. From baseline to the end of the trial, the mean BMI decreased in the intervention group, whereas it increased in the control group; the mean between-group difference in BMI change was -0.46 (95% CI, -0.67 to -0.25; P < .001), which showed no evidence of difference across different regions, sexes, maternal education levels, and primary caregivers (parents vs nonparents). The prevalence of obesity decreased by 27.0% of the baseline figure (a relative decrease) in the intervention group, compared with 5.6% in the control group. The intervention also improved other adiposity outcomes, dietary, sedentary, and physical activity behaviors, and obesity-related knowledge, but it did not change moderate- to vigorous-intensity physical activity, physical fitness, or blood pressure. No adverse events were observed during the intervention.

CONCLUSIONS AND RELEVANCE

The multifaceted intervention effectively reduced the mean BMI and obesity prevalence in primary school children across socioeconomically distinct regions in China, suggesting its potential for national scaling.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03665857.

Health policy and public health implications of obesity in China

China has experienced many drastic social and economic changes and shifts in people's lifestyles since the 1990s, in parallel with the fast rising prevalence of obesity. About half of adults and a fifth of children have overweight or obesity according to the Chinese criteria, making China the country with the highest number of people with overweight or obesity in the world. Assuming that observed time trends would continue in the future, we projected the prevalence of and the number of people affected by overweight and obesity by 2030, and the associated medical costs. The rising incidence of obesity and number of people affected, as well as the related health and economic consequences, place a huge burden on China's health-care system. China has made many efforts to tackle obesity, including the implementation of relevant national policies and programmes. However, these measures are inadequate for controlling the obesity epidemic. In the past decade, China has attached great importance to public health, and the Healthy China 2030 national strategy initiated in 2016 provides a historical opportunity to establish comprehensive national strategies for tackling obesity. China is well positioned to explore an effective model to overcome the obesity epidemic; however, strong commitment and leadership from central and local governments are needed, as well as active participation of all related society sectors and individual citizens. TRANSLATION: For the Chinese translation of the paper see Supplementary Materials section.

Childhood obesity prevention policies in Iran: a policy analysis of agenda-setting using Kingdon's multiple streams

BACKGROUND

Pediatric obesity is one of the most important health challenges of the twenty-first century. Primary prevention of childhood obesity, can lessen its consequences. This study aims to assess childhood obesity prevention policies in Iran through a policy analysis of agenda-setting using Kingdon's multiple streams.

METHODS

A qualitative study was conducted using in-depth interviews with 39 key informants and document review from different stages of the policymaking process of childhood and adolescent obesity prevention programs in Iran. The analysis of documents and interviews were guided based on Kingdon's multiple streams (problem, policy and political streams).

RESULTS

The important factors of the problem stream were the high prevalence of childhood and adolescent obesity and its risk factors in Iran. In the policy stream, a focus on preventing non-communicable diseases in the health system, increasing the workforce in health centers, promoting health school programs, and creating healthy eating buffets in schools was identified. Under the political stream, the impact of the WHO ECHO program in 2015 and the implementation of the health system transformation plan in Iran in the new government took place after 2013, caused the Iran ECHO program entered the agenda and implemented from 2016.

CONCLUSIONS

Now that a window of opportunity for childhood and adolescent obesity prevention policymaking has been created, the problems such as the therapeutic approach in the health system, the existence of sanctions against Iran and outbreak of coronavirus disease-19 (COVID-19), have hindered the successful implementation of this policy and the opportunity window has not been well used. However, actors need political support from the high levels of government to keep this policy on the agenda.

How effective are physical activity interventions when they are scaled-up: a systematic review

Background

The ‘scale-up’ of effective physical activity interventions is required if they are to yield improvements in population health. The purpose of this study was to systematically review the effectiveness of community-based physical activity interventions that have been scaled-up. We also sought to explore differences in the effect size of these interventions compared with prior evaluations of their efficacy in more controlled contexts, and describe adaptations that were made to interventions as part of the scale-up process.

Methods

We performed a search of empirical research using six electronic databases, hand searched reference lists and contacted field experts. An intervention was considered ‘scaled-up’ if it had been intentionally delivered on a larger scale (to a greater number of participants, new populations, and/or by means of different delivery systems) than a preceding randomised control trial (‘pre-scale’) in which a significant intervention effect (p < 0.05) was reported on any measure of physical activity. Effect size differences between pre-scale and scaled up interventions were quantified ([the effect size reported in the scaled-up study / the effect size reported in the pre-scale-up efficacy trial] × 100) to explore any scale-up ‘penalties’ in intervention effects.

Results

We identified 10 eligible studies. Six scaled-up interventions appeared to achieve significant improvement on at least one measure of physical activity. Six studies included measures of physical activity that were common between pre-scale and scaled-up trials enabling the calculation of an effect size difference (and potential scale-up penalty). Differences in effect size ranged from 132 to 25% (median = 58.8%), suggesting that most scaled-up interventions typically achieve less than 60% of their pre-scale effect size. A variety of adaptations were made for scale-up – the most common being mode of delivery.

Conclusion

The majority of interventions remained effective when delivered at-scale however their effects were markedly lower than reported in pre-scale trials. Adaptations of interventions were common and may have impacted on the effectiveness of interventions delivered at scale. These outcomes provide valuable insight for researchers and public health practitioners interested in the design and scale-up of physical activity interventions, and contribute to the growing evidence base for delivering health promotion interventions at-scale.

Trial registration

PROSPERO CRD42020144842.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01080-4.

Effectiveness of school-based interventions to prevent obesity among children aged 4 to 12 years old in middle-income countries: A systematic review and meta-analysis

Economic and accompanying nutrition transition in middle-income countries is resulting in rapidly increasing childhood obesity prevalence, exceeding acceleration rates in the West. Previous school-based obesity prevention reviews have mainly included studies from high-income countries. This review aimed to summarize the evidence from randomized controlled trials evaluating the effectiveness of school-based interventions in preventing childhood obesity in middle-income countries. Six electronic databases were searched: MEDLINE, EMBASE, CINAHL Plus, LILACS, IBECS and WPRIM. Eligibility criteria included middle-income country setting, randomized/cluster-randomized controlled trials, children aged 4-12 years and school-based interventions targeting dietary intake and/or physical activity. Twenty-one cluster-randomized controlled trials, conducted in Asia (n = 10), South America (n = 4), North America (n = 4) and the Middle East (n = 3), were included. Fifteen studies reported a significant intervention effect on at least one adiposity-related outcome. Characteristics of effective interventions included combined diet and PA interventions, school teacher-delivery, duration of >8 months, parental involvement, education sessions and school food modifications. The risk of bias in these trials was mixed. The pooled estimate of the odds ratio for obesity in intervention versus control schools (nine studies) was 0.77; 95% CI, 0.63 to 0.94; p = 0.009. In conclusion, there is some evidence to support school-based interventions in preventing childhood obesity in middle-income countries.

National School-Based Health Lifestyles Intervention in Chinese Children and Adolescents on Obesity and Hypertension

Introduction: This study aimed to examine the effectiveness of the national school-based intervention on both obesity and high blood pressure in Chinese children and adolescents aged 6-18 years. Methods: The national school-based cluster non-randomized controlled trial was done in seven provinces from September 2013 to February 2014. A total of 23,175 children and adolescents in the control group and 25,702 in the intervention group were included in this trial with a mean follow-up of 6.7 ± 0.9 months. Mixed-effects regression models were used to evaluate the effect of the interventions on body weight and blood pressure (BP). Results: A significant upward in the body mass index (BMI) levels but downward in systolic BP (SBP), diastolic BP (DBP), BMI Z-scores, SBP Z-scores, and DBP Z-scores were witnessed in the intervention group compared to those in the control group (<0.001). Subgroup analyses presented significant intervention effects in children aged 6-12 years for BMI, SBP, DBP, and their standardized values Z-scores, but no effective results were found in adolescents aged 13-18 years. Stratification analyses based on the dynamic weight changes presented non-differential HBP, SHBP, and DHBP prevalence gaps between the control and intervention groups. Children aged 6-12 years with higher BMI percentiles at baseline presented obvious declines in SBP and DBP standardized values Z-scores. Conclusion: A mean 6-month multi-centered school-based comprehensive obesity intervention in China yields a small to null effect on obesity and hypertension with increasing age; the early age before 12 years may be the key period for interventions, and the younger, the better. Precise and high-intensity interventions targeting the population at different stages of childhood and adolescence are urgently needed to be developed. Clinical Trial Registration: https://www.clinicaltrials.gov/, identifier: NCT02343588.

The effectiveness of pediatric obesity prevention policies: a comprehensive systematic review and dose-response meta-analysis of controlled clinical trials

BACKGROUND

Childhood obesity persists as a serious public health problem. In the current meta-analysis, we summarized the results of controlled trials that evaluated the effect of obesity prevention policies in children and adolescents.

METHODS

Three databases (SCOPUS, PubMed and Embase) were searched for studies published before the 6th April 2020, by reported outcome measures of body mass index (BMI) and BMI-Zscore. Forty-seven studies reported BMI, while 45 studies reported BMI-Zscore as final outcome.

RESULTS

The results showed that the obesity-prevention policies had significant effect in reducing BMI (WMD: - 0.127; CI - 0.198, - 0.056; P < 0.001). These changes were not significant for BMI-Zscore (WMD: - 0.020; CI - 0.061, 0.021; P = 0.340). In dose-response meta-analysis, a non-linear association was reported between the duration of intervention and BMI (Pnonlinearity < 0.001) as well as BMI-Zscore (Pnonlinearity = 0.023). In subgroup analysis, the more favorite results were observed for 5-10 years old, with combination of physical activity and diet as intervention materials.

CONCLUSION

In conclusion, the obesity prevention policies in short-term periods of less than 2 years, in rather early age of school with approaches of change in both of diet and physical activity, could be more effective in prevention of childhood obesity. Trial registration PROSPERO registration number: CRD42019138359.

A sex/gender perspective on interventions to promote children's and adolescents' overall physical activity: results from genEffects systematic review

Background

To evaluate the effects of interventions on children’s and adolescents’ overall physical activity (PA) for boys and girls separately and to appraise the extent to which the studies haven taken sex/gender into account.

Methods

Systematic review and semi-quantitative analysis. Eleven electronic databases were searched to identify all relevant randomized and non-randomized controlled trials. Studies had to report overall PA as the main outcome to be eligible for inclusion in the review. The main outcomes of the studies is a quantified measure of overall PA. Additionally, all studies had to report sex/gender disaggregated overall PA at baseline and/or follow up and/or explain how they dealt with sex/gender during outcome analysis (i.e., sex/gender adjusted analyses) and/or report that there were no differences in the outcome when looking at sex/gender. PRISMA guidelines were followed. Two authors independently screened studies for eligibility and assessed the risk of bias. Semi-quantitative analyses were conducted to evaluate intervention effects, taking into account the extent to which studies have considered sex/gender aspects. To evaluate sex/gender considerations in primary studies, a newly developed sex/gender checklist was used. The study was registered previously (registration number CRD42018109528).

Results

In total, 97 articles reporting 94 unique studies with 164 outcomes for overall PA were included in the present review. Average sample size was 829 participants, ranging from five to 9839. Participants’ ages ranged from three to 19 years. Our review shows that overall 35% of PA outcomes had significant effects in increasing overall PA of children and adolescents. Not including single sex/gender studies, 105 out of 120 PA outcomes resulted in same intervention effects for boys and girls. The interventions reported to have similar effects on PA outcomes for boys and girls showed higher quality of reporting sex/gender aspects of measurement instruments, participant flow and intervention content and materials than PA outcomes with effects only in boys or only in girls. Overall, consideration of sex/gender aspects in intervention studies is low.

Conclusions

There is still a need to address sufficient consideration of sex/gender aspects in developing and implementing interventions in the context of PA.

A Community-Based Lifestyle-Integrated Physical Activity Intervention to Enhance Physical Activity, Positive Family Communication, and Perceived Health in Deprived Families: A Cluster Randomized Controlled Trial

Background: Zero-time exercise (ZTEx) is an approach integrating simple strength- and stamina-enhancing physical activity into daily life. The study evaluated the effectiveness of a community-based lifestyle-integrated physical activity intervention using ZTEx to enhance participants' physical activity, family communication, perceived health and happiness, and family harmony.

Methods: A parallel group, cluster randomized controlled trial was conducted in a sample of 673 participants from eight Integrated Family Service Centers in Hong Kong. The experimental group (n = 316) received a physical activity intervention. The control group (n = 357) received information on healthy eating. Both groups received three face-to-face intervention sessions (totalling 6 h and 30 min) and 16 text messages. The primary outcome was the change in days spent engaged in ZTEx. Secondary outcomes included changes in sitting time, days engaged in moderate or vigorous physical activities, family communication (encouraging and engaging family members in ZTEx), dietary habits, perceived health and happiness, and family harmony. Self-administered questionnaires were used at baseline and at 3, 6, and 12 months. Mixed effects models with intention-to-treat analysis was used.

Results: Compared with the control group at 3 months, the experimental group showed significantly greater increases of 1.3 days spent doing ZTEx (Cohen's d: 0.60), 0.3 days spent doing moderate physical activity (Cohen's d: 0.08), 0.3 days encouraging family members to do ZTEx (Cohen's d: 0.16), and 0.7 days doing ZTEx with family members (Cohen's d: 0.39) during the 7 days prior. At 3 months, the experimental group also showed a significantly greater improvement in perceived health, by a score of 0.2 (Cohen's d: 0.14). The effect sizes ranged from small to medium, with similar intervention effects at the 6-month and 1-year assessments. Compared with the experimental group, the control group showed a significantly greater reduction of 0.4 days on which sweetened beverages were consumed (95% CI: 0.01, 0.9, p < 0.05, Cohen's d: 0.28). The qualitative results supported the quantitative findings.

Conclusions: Our findings show that a community-based lifestyle-integrated physical activity (PA) intervention can enhance physical activity, family communication, and perceived health in deprived families in Hong Kong.

Trial registration: The research protocol was retrospectively registered at the National Institutes of Health (identifier number: NCT02601534) on November 10, 2015.

A school-based, multi-faceted health promotion programme to prevent obesity among children: protocol of a cluster-randomised controlled trial (the DECIDE-Children study)

INTRODUCTION

Obesity is a public health concern that is becoming increasingly more serious worldwide. Effective and sustainable childhood obesity prevention strategies may help to reduce the prevalence of obesity and may have an impact on lifelong health. However, few such strategies have been rigorously evaluated for Chinese children in different regions of China.

METHODS AND ANALYSIS

The Diet, ExerCIse and CarDiovascular hEalth-Children is a cluster-randomised controlled trial that aims to assess the effectiveness and sustainability of a school-based, multi-faceted intervention to prevent obesity among Grade 4 primary school students (8-10 years old) in China. Twenty-four schools (approximately 1200 students) from above average, average and below average developed regions in China will be randomised to an intervention (12 schools) or usual practice (12 schools) group. The intervention will last for one school year (9 months) and consists of activities towards students, parents and school environment. A smartphone application will be used to assist in providing information on, monitoring and providing feedback on the behaviours and body weight of the students. Data will be collected at baseline, 4 months, 9 months and 21 months. The primary outcome will be the difference between groups in the change in students' body mass index at 9 months after the baseline investigation. The secondary outcomes will include the differences between groups in the changes in anthropometric measures, diet, physical activity levels and other measures at the follow-up visits. A variety of process evaluation methods will be used to evaluate the implementation process of the complex intervention.

ETHICS AND DISSEMINATION

This study was approved by the Peking University Institution Review Board (IRB00001052-18021). The results will be disseminated through publication in peer-reviewed journals, presentations at conferences and in lay summaries provided to school staff and participants.

TRIAL REGISTRATION NUMBER

NCT03665857.

The CHIRPY DRAGON intervention in preventing obesity in Chinese primary-school--aged children: A cluster-randomised controlled trial

BACKGROUND

In countries undergoing rapid economic transition such as China, rates of increase in childhood obesity exceed that in the West. However, prevention trials in these countries are inadequate in both quantity and methodological quality. In high-income countries, recent reviews have demonstrated that school-based prevention interventions are moderately effective but have some methodological limitations. To address these issues, this study evaluated clinical- and cost- effectiveness of the Chinese Primary School Children Physical Activity and Dietary Behaviour Changes Intervention (CHIRPY DRAGON) developed using the United Kingdom Medical Research Council complex intervention framework to prevent obesity in Chinese primary-school-aged children.

METHODS AND FINDINGS

In this cluster-randomised controlled trial, we recruited 40 state-funded primary schools from urban districts of Guangzhou, China. A total of 1,641 year-one children with parent/guardian consent took part in baseline assessments prior to stratified randomisation of schools (intervention arm, 20 schools, n = 832, mean age = 6.15 years, 55.6% boys; control arm n = 809, mean age = 6.14 years, 53.3% boys). The 12-month intervention programme included 4 school- and family-based components delivered by 5 dedicated project staff. We promoted physical activity and healthy eating behaviours through educational and practical workshops, family activities, and supporting the school to improve physical activity and food provision. The primary outcome, assessed blind to allocation, was between-arm difference in body mass index (BMI) z score at completion of the intervention. A range of prespecified, secondary anthropometric, behavioural, and psychosocial outcomes were also measured. We estimated cost effectiveness based on quality-adjusted life years (QALYs), taking a public sector perspective. Attrition was low with 55 children lost to follow up (3.4%) and no school dropout. Implementation adherence was high. Using intention to treat analysis, the mean difference (MD) in BMI z scores (intervention - control) was -0.13 (-0.26 to 0.00, p = 0.048), with the effect being greater in girls (MD = -0.18, -0.32 to -0.05, p = 0.007, p for interaction = 0.015) and in children with overweight or obesity at baseline (MD = -0.49, -0.73 to -0.25, p < 0.001, p for interaction < 0.001). Significant beneficial intervention effects were also observed on consumption of fruit and vegetables, sugar-sweetened beverages and unhealthy snacks, screen-based sedentary behaviour, and physical activity in the intervention group. Cost effectiveness was estimated at £1,760 per QALY, with the probability of the intervention being cost effective compared with usual care being at least 95% at a willingness to pay threshold of £20,000 to 30,000 per QALY. There was no evidence of adverse effects or harms. The main limitations of this study were the use of dietary assessment tools not yet validated for Chinese children and the use of the UK value set to estimate QALYS.

CONCLUSIONS

This school- and family-based obesity prevention programme was effective and highly cost effective in reducing BMI z scores in primary-school-aged children in China. Future research should identify strategies to enhance beneficial effects among boys and investigate the transferability of the intervention to other provinces in China and countries that share the same language and cultures.

TRIAL REGISTRATION

ISRCTN Identifier ISRCTN11867516.

A systematic review and meta-analysis of the overall effects of school-based obesity prevention interventions and effect differences by intervention components

Background

Childhood obesity is a serious public health concern. School-based interventions hold great promise to combat the rising trend of childhood obesity. This systematic review aimed to assess the overall effects of school-based obesity prevention interventions, and to investigate characteristics of intervention components that are potentially effective for preventing childhood obesity.

Methods

We systematically searched MEDLINE, CENTRAL and Embase databases to identify randomized- or cluster randomized- controlled trials of school-based obesity interventions published between 1990 and 2019. We conducted meta-analyses and subgroup analyses to determine the overall effects of obesity prevention programs and effect differences by various characteristics of intervention components on body mass index (BMI) or BMI Z-score of children.

Results

This systematic review included a total of 50 trials (reported by 56 publications). Significant differences were found between groups on BMI (− 0.14 kg/m² (95% confidence interval: − 0.21, − 0.06)) and BMI Z-score (− 0.05 (− 0.10, − 0.01)) for single-component interventions; significant differences were also found between groups on BMI (− 0.32 (− 0.54, − 0.09) kg/m²) and BMI Z-score (− 0.07 (− 0.14, − 0.001)) for multi-component interventions. Subgroup analyses consistently demonstrated that effects of single-component (physical activity) interventions including curricular sessions (− 0.30 (− 0.51, − 0.10) kg/m² in BMI) were stronger than those without curricular sessions (− 0.04 (− 0.17, 0.09) kg/m² in BMI); effects of single-component (physical activity) interventions were also strengthened if physical activity sessions emphasized participants’ enjoyment (− 0.19 (− 0.33, − 0.05) kg/m² in BMI for those emphasizing participants’ enjoyment; − 0.004 (− 0.10, 0.09) kg/m² in BMI for those not emphasizing participants’ enjoyment). The current body of evidence did not find specific characteristics of intervention components that were consistently associated with improved efficacy for multi-component interventions (P > 0.05).

Conclusions

School-based interventions are generally effective in reducing excessive weight gain of children. Our findings contribute to increased understandings of potentially effective intervention characteristics for single-component (physical activity) interventions. The impact of combined components on effectiveness of multi-component interventions should be the topic of further research. More high-quality studies are also needed to confirm findings of this review.

Scaling-up evidence-based obesity interventions: A systematic review assessing intervention adaptations and effectiveness and quantifying the scale-up penalty

Maximizing the benefits of investments in obesity research requires effective interventions to be adopted and disseminated broadly across populations (scaled-up). However, interventions often need considerable adaptation to enable implementation at scale, a process that can reduce the effects of interventions. A systematic review was undertaken for trials that sought to deliver an obesity intervention to populations on a larger scale than a preceding randomized controlled trial (RCT) that established its efficacy. Ten scaled-up obesity interventions (six prevention and four treatment) were included. All trials made adaptations to interventions as part of the scale-up process, with mode of delivery adaptations being most common. A meta-analysis of body mass index (BMI)/BMI z score (zBMI) from three prevention RCTs found no significant benefit of scaled-up interventions relative to control (standardized mean difference [SMD] = 0.03; 95% CI, -0.09 to 0.15, P = 0.639 - I²  = 0.0%). All four treatment interventions reported significant improvement on all measures of weight status. Pooled BMI/zBMI data from prevention trials found significantly lower effects among scaled-up intervention trials than those reported in pre-scale-up efficacy trials (SMD = -0.11; 95% CI, -0.20 to -0.02, P = 0.018 - I²  = 0.0%). Across measures of weight status, physical activity/sedentary behaviour, and nutrition, the effects reported in scaled-up interventions were typically 75% or less of the effects reported in pre-scale-up efficacy trials. The findings underscore the challenge of scaling-up obesity interventions.