HEALTHY intervention: fitness, physical activity, and metabolic syndrome results

Coordinated Approach: Comprehensive Policy and Action Planning

BACKGROUND

Schools play a vital role in student health, and a collaborative approach may affect health factors such as physical activity (PA) and nutrition. There is a lack of recent literature synthesizing collaborative approaches in K-12 settings. We present updated evidence about interventions that used a coordinated school health approach to support K-12 student PA and nutrition in the United States.

METHODS

A 2-phase literature review search included a search of systematic reviews for individual qualifying studies (2010-2018), followed by a search for individual articles (2010-2020) that evaluated a coordinated approach or use of school wellness councils, committees, or teams to address PA and/or nutrition.

RESULTS

We identified 35 articles describing 30 studies and grouped them by intervention type. Interventions demonstrated promising findings for environmental changes and student dietary and PA behaviors.

IMPLICATIONS

Coordinated and multicomponent interventions demonstrated significant improvements or null results, indicating that implementation of programs and/or policies to promote healthier eating and PA practices may support and do not appear to hinder environmental or behavioral outcomes.

CONCLUSIONS

Schools can use a coordinated approach to implement opportunities for PA and nutrition; this may influence students' PA and dietary behaviors.

School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6 to 18

BACKGROUND

Physical activity among children and adolescents is associated with lower adiposity, improved cardio-metabolic health, and improved fitness. Worldwide, fewer than 30% of children and adolescents meet global physical activity recommendations of at least 60 minutes of moderate to vigorous physical activity per day. Schools may be ideal sites for interventions given that children and adolescents in most parts of the world spend a substantial amount of time in transit to and from school or attending school.

OBJECTIVES

The purpose of this review update is to summarise the evidence on effectiveness of school-based interventions in increasing moderate to vigorous physical activity and improving fitness among children and adolescents 6 to 18 years of age. Specific objectives are: • to evaluate the effects of school-based interventions on increasing physical activity and improving fitness among children and adolescents; • to evaluate the effects of school-based interventions on improving body composition; and • to determine whether certain combinations or components (or both) of school-based interventions are more effective than others in promoting physical activity and fitness in this target population.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, BIOSIS, SPORTDiscus, and Sociological Abstracts to 1 June 2020, without language restrictions. We screened reference lists of included articles and relevant systematic reviews. We contacted primary authors of studies to ask for additional information.

SELECTION CRITERIA

Eligible interventions were relevant to public health practice (i.e. were not delivered by a clinician), were implemented in the school setting, and aimed to increase physical activity among all school-attending children and adolescents (aged 6 to 18) for at least 12 weeks. The review was limited to randomised controlled trials. For this update, we have added two new criteria: the primary aim of the study was to increase physical activity or fitness, and the study used an objective measure of physical activity or fitness. Primary outcomes included proportion of participants meeting physical activity guidelines and duration of moderate to vigorous physical activity and sedentary time (new to this update). Secondary outcomes included measured body mass index (BMI), physical fitness, health-related quality of life (new to this update), and adverse events (new to this update). Television viewing time, blood cholesterol, and blood pressure have been removed from this update.  DATA COLLECTION AND ANALYSIS: Two independent review authors used standardised forms to assess each study for relevance, to extract data, and to assess risk of bias. When discrepancies existed, discussion occurred until consensus was reached. Certainty of evidence was assessed according to GRADE. A random-effects meta-analysis based on the inverse variance method was conducted with participants stratified by age (children versus adolescents) when sufficient data were reported. Subgroup analyses explored effects by intervention type.

MAIN RESULTS

Based on the three new inclusion criteria, we excluded 16 of the 44 studies included in the previous version of this review. We screened an additional 9968 titles (search October 2011 to June 2020), of which 978 unique studies were potentially relevant and 61 met all criteria for this update. We included a total of 89 studies representing complete data for 66,752 study participants. Most studies included children only (n = 56), followed by adolescents only (n = 22), and both (n = 10); one study did not report student age. Multi-component interventions were most common (n = 40), followed by schooltime physical activity (n = 19), enhanced physical education (n = 15), and before and after school programmes (n = 14); one study explored both enhanced physical education and an after school programme. Lack of blinding of participants, personnel, and outcome assessors and loss to follow-up were the most common sources of bias.  Results show that school-based physical activity interventions probably result in little to no increase in time engaged in moderate to vigorous physical activity (mean difference (MD) 0.73 minutes/d, 95% confidence interval (CI) 0.16 to 1.30; 33 studies; moderate-certainty evidence) and may lead to little to no decrease in sedentary time (MD -3.78 minutes/d, 95% CI -7.80 to 0.24; 16 studies; low-certainty evidence). School-based physical activity interventions may improve physical fitness reported as maximal oxygen uptake (VO₂max) (MD 1.19 mL/kg/min, 95% CI 0.57 to 1.82; 13 studies; low-certainty evidence). School-based physical activity interventions may result in a very small decrease in BMI z-scores (MD -0.06, 95% CI -0.09 to -0.02; 21 studies; low-certainty evidence) and may not impact BMI expressed as kg/m² (MD -0.07, 95% CI -0.15 to 0.01; 50 studies; low-certainty evidence). We are very uncertain whether school-based physical activity interventions impact health-related quality of life or adverse events.

AUTHORS' CONCLUSIONS

Given the variability of results and the overall small effects, school staff and public health professionals must give the matter considerable thought before implementing school-based physical activity interventions. Given the heterogeneity of effects, the risk of bias, and findings that the magnitude of effect is generally small, results should be interpreted cautiously.

Time-efficient intervention to improve older adolescents' cardiorespiratory fitness: findings from the 'Burn 2 Learn' cluster randomised controlled trial

BACKGROUND

Cardiorespiratory fitness (CRF) is an important marker of current and future health status. The primary aim of our study was to evaluate the impact of a time-efficient school-based intervention on older adolescents' CRF.

METHODS

Two-arm cluster randomised controlled trial conducted in two cohorts (February 2018 to February 2019 and February 2019 to February 2020) in New South Wales, Australia. Participants (N=670, 44.6% women, 16.0±0.43 years) from 20 secondary schools: 10 schools (337 participants) were randomised to the Burn 2 Learn (B2L) intervention and 10 schools (333 participants) to the control. Teachers in schools allocated to the B2L intervention were provided with training, resources, and support to facilitate the delivery of high-intensity interval training (HIIT) activity breaks during curriculum time. Teachers and students in the control group continued their usual practice. The primary outcome was CRF (20 m multi-stage fitness test). Secondary outcomes were muscular fitness, physical activity, hair cortisol concentrations, mental health and cognitive function. Outcomes were assessed at baseline, 6 months (primary end-point) and 12 months. Effects were estimated using mixed models accounting for clustering.

RESULTS

We observed a group-by-time effect for CRF (difference=4.1 laps, 95% CI 1.8 to 6.4) at the primary end-point (6 months), but not at 12 months. At 6 months, group-by-time effects were found for muscular fitness, steps during school hours and cortisol.

CONCLUSIONS

Implementing HIIT during curricular time improved adolescents' CRF and several secondary outcomes. Our findings suggest B2L is unlikely to be an effective approach unless teachers embed sessions within the school day.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12618000293268).

Intervention Effects of "Girls on the Move" on Increasing Physical Activity: A Group Randomized Trial

BACKGROUND

Limited intervention success in increasing and sustaining girls' moderate-to-vigorous physical activity (MVPA) underscores a need for continued research.

PURPOSE

The aim of this study was to evaluate the effect of a 17-week Girls on the Move (GOTM) intervention on increasing MVPA among fifth- to eighth-grade girls.

METHODS

This study is a group (cluster) randomized trial, including 24 schools, pair matched and assigned to intervention (n = 12) or control (n = 12) conditions. Participants included 1,519 girls in racially diverse public schools in urban, underserved areas of the Midwestern USA. The intervention included three components: (i) 90-min after-school physical activity (PA) club offered 3 days/week; (ii) two motivational, individually tailored counseling sessions; and (iii) an interactive Internet-based session at the midpoint of the intervention. Main outcome measures were weighted mean minutes of MVPA per week post-intervention and at 9-month follow-up measured via accelerometer.

RESULTS

No between-group differences occurred for weighted mean minutes of MVPA per week at post-intervention (B = -0.08, p = .207) or 9-month follow-up (B = -0.09, p = .118) while controlling for baseline MVPA.

CONCLUSIONS

Research is needed to identify interventions that assist girls in attaining and maintaining adequate PA.

CLINICALTRIALS.GOV IDENTIFIER

NCT01503333.

Effect of multidimensional lifestyle interventions on metabolic risk reduction in children: a cluster randomised controlled trial

Few clinical trials have investigated lifestyle intervention effect on metabolic health in children. The study aimed to examine the effect of diet and physical activity intervention on the reduction of clustered metabolic risk score (CMRS) in children and moderators and mediators of the intervention effect. A multicentre, clustered randomised controlled trial was conducted with examination conducted at baseline and after intervention over one year. 7110 children (49.7% girls) with a mean of 9.06 (95% CI: 9.03, 9.09) years were included in the analysis. In Beijing, each three schools were randomly assigned to diet-only, physical activity-only intervention and control groups. In five other urban cities, each 15 schools were randomly assigned to comprehensive intervention and control groups. CMRS was computed by summing the Z scores of % fat mass, systolic blood pressure, fasting glucose, ratio of cholesterol to high-density lipoprotein, and triglyceride. Compared with controls (n = 2808), children in the comprehensive intervention group (n = 2848) had more reduction in CMRS (multivariate-adjusted mean difference (95% CI): -0.49 (-0.85, -0.14)). The body mass index (BMI) reduction explained 7.3% (95% CI 2.8%-18.1%) of the total intervention effect. The intervention was more effective in children with higher birthweight, lower parental BMI, or complete parental data. Diet-only or physical activity-only intervention had non-significant effects on CMRS reduction. Our multidimensional comprehensive intervention resulted in significant reduction in CMRS in primary school children and this effect was modified by birthweight, parental BMI, and parental involvement. A minority of metabolic risk reduction was mediated through BMI. Clinical Trial Registry number and website: ChiCTR-PRC-09000402, URL: http://www.chictr.org.cn.

Evaluation of an Intervention to Increase Physical Activity in Low-Income, Urban Middle Schools

BACKGROUND

Physical education (PE) can provide opportunities to engage in daily moderate-to-vigorous physical activity (MVPA), but MVPA levels in many classes are low. This study examines MVPA during middle school PE lessons before and after receiving the SPARK (Sports, Play, and Active Recreation for Kids) program.

METHODS

Sixteen schools were enrolled in the study. PE teachers at eight schools received the intervention. PE lessons at all schools (N = 561) were observed over 2 years. Hierarchical linear regression models examined the effect of the intervention on the amount and consistency of MVPA and sedentary behavior.

RESULTS

An average of 13.7% of observed class time was spent in MVPA (approximately 5 minutes of a 60-minute class), compared to 27.5% of time spent sedentary. There was no evidence that the curriculum resulted in increased MVPA or consistent MVPA, or that it decreased sedentary behavior. Findings also suggested that contextual factors may contribute to physical activity levels in PE.

CONCLUSIONS

Mixed evaluation findings of the SPARK middle school curriculum demonstrate that an out-of-the-box curriculum does not have the same results in all contexts. Implications for school health are described based upon findings. Further research is needed to identify effective strategies to increase MVPA for adolescents both in and outside of PE.

School-Based Physical Activity Interventions in Prevocational Adolescents: A Systematic Review and Meta-Analyses

PURPOSE

Literature detailing the effectiveness of school-based physical activity promotion interventions in prevocational adolescents was reviewed to identify effective intervention characteristics.

METHODS

The search strategy assessed studies against inclusion criteria study design, study population, school setting, language, and construct. The risk of bias of the included studies was assessed, and extractions were made of the physical activity (PA) level outcome measures and intervention characteristics regarding organizational, social, and content features. A meta-analysis was conducted to determine the overall effect of the interventions on the PA level. Identification of effective intervention characteristics was done by subgroup analyses. Meta-regression analysis was performed with PA level as dependent variable and intervention characteristics as covariates.

RESULTS

A total of 40 eligible studies was included for meta-analyses. Among the included studies, the overall intervention effect on increasing the PA level of prevocational adolescents was weak (standardized mean difference [SMD] .19, 95% confidence interval [CI] .12-.27). Intervention characteristics that improve the effect size to a moderate level were intracurricular PA (SMD .43, 95% CI .19-.68), involving school staff in an intracurricular intervention (SMD .37, 95% CI .16-.58) and a tailored intracurricular intervention (SMD .35, 95% CI .13-.58). Meta-regression analysis confirmed PA as a positive predictor.

CONCLUSIONS

The effect of a school-based PA intervention was small to moderate. A sensible choice in the assembly of a multicomponent school-based PA intervention increases the effectiveness considerably. Physical education teachers, school administrators, and policy makers should consider organizational (intracurriculum, short and medium duration), personal (tailoring, participation), social (school staff) and content (PA) determinants.

Interventions for preventing obesity in children

EDITORIAL NOTE

This Cochrane review is now out of date and should not be used for reference. It has been split into four age groups and updated. Please refer to the 5‐11 and 12‐18 age group Cochrane reviews which were published in May 2024: https://doi.org/10.1002/14651858.CD015328.pub2 https://doi.org/10.1002/14651858.CD015330.pub2 The 2‐4 age group Cochrane review is planned for publication in September 2024.

BACKGROUND

Prevention of childhood obesity is an international public health priority given the significant impact of obesity on acute and chronic diseases, general health, development and well-being. The international evidence base for strategies to prevent obesity is very large and is accumulating rapidly. This is an update of a previous review.

OBJECTIVES

To determine the effectiveness of a range of interventions that include diet or physical activity components, or both, designed to prevent obesity in children.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsychINFO and CINAHL in June 2015. We re-ran the search from June 2015 to January 2018 and included a search of trial registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of diet or physical activity interventions, or combined diet and physical activity interventions, for preventing overweight or obesity in children (0-17 years) that reported outcomes at a minimum of 12 weeks from baseline.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data, assessed risk-of-bias and evaluated overall certainty of the evidence using GRADE. We extracted data on adiposity outcomes, sociodemographic characteristics, adverse events, intervention process and costs. We meta-analysed data as guided by the Cochrane Handbook for Systematic Reviews of Interventions and presented separate meta-analyses by age group for child 0 to 5 years, 6 to 12 years, and 13 to 18 years for zBMI and BMI.

MAIN RESULTS

We included 153 RCTs, mostly from the USA or Europe. Thirteen studies were based in upper-middle-income countries (UMIC: Brazil, Ecuador, Lebanon, Mexico, Thailand, Turkey, US-Mexico border), and one was based in a lower middle-income country (LMIC: Egypt). The majority (85) targeted children aged 6 to 12 years.Children aged 0-5 years: There is moderate-certainty evidence from 16 RCTs (n = 6261) that diet combined with physical activity interventions, compared with control, reduced BMI (mean difference (MD) -0.07 kg/m2, 95% confidence interval (CI) -0.14 to -0.01), and had a similar effect (11 RCTs, n = 5536) on zBMI (MD -0.11, 95% CI -0.21 to 0.01). Neither diet (moderate-certainty evidence) nor physical activity interventions alone (high-certainty evidence) compared with control reduced BMI (physical activity alone: MD -0.22 kg/m2, 95% CI -0.44 to 0.01) or zBMI (diet alone: MD -0.14, 95% CI -0.32 to 0.04; physical activity alone: MD 0.01, 95% CI -0.10 to 0.13) in children aged 0-5 years.Children aged 6 to 12 years: There is moderate-certainty evidence from 14 RCTs (n = 16,410) that physical activity interventions, compared with control, reduced BMI (MD -0.10 kg/m2, 95% CI -0.14 to -0.05). However, there is moderate-certainty evidence that they had little or no effect on zBMI (MD -0.02, 95% CI -0.06 to 0.02). There is low-certainty evidence from 20 RCTs (n = 24,043) that diet combined with physical activity interventions, compared with control, reduced zBMI (MD -0.05 kg/m2, 95% CI -0.10 to -0.01). There is high-certainty evidence that diet interventions, compared with control, had little impact on zBMI (MD -0.03, 95% CI -0.06 to 0.01) or BMI (-0.02 kg/m2, 95% CI -0.11 to 0.06).Children aged 13 to 18 years: There is very low-certainty evidence that physical activity interventions, compared with control reduced BMI (MD -1.53 kg/m2, 95% CI -2.67 to -0.39; 4 RCTs; n = 720); and low-certainty evidence for a reduction in zBMI (MD -0.2, 95% CI -0.3 to -0.1; 1 RCT; n = 100). There is low-certainty evidence from eight RCTs (n = 16,583) that diet combined with physical activity interventions, compared with control, had no effect on BMI (MD -0.02 kg/m2, 95% CI -0.10 to 0.05); or zBMI (MD 0.01, 95% CI -0.05 to 0.07; 6 RCTs; n = 16,543). Evidence from two RCTs (low-certainty evidence; n = 294) found no effect of diet interventions on BMI.Direct comparisons of interventions: Two RCTs reported data directly comparing diet with either physical activity or diet combined with physical activity interventions for children aged 6 to 12 years and reported no differences.Heterogeneity was apparent in the results from all three age groups, which could not be entirely explained by setting or duration of the interventions. Where reported, interventions did not appear to result in adverse effects (16 RCTs) or increase health inequalities (gender: 30 RCTs; socioeconomic status: 18 RCTs), although relatively few studies examined these factors.Re-running the searches in January 2018 identified 315 records with potential relevance to this review, which will be synthesised in the next update.

AUTHORS' CONCLUSIONS

Interventions that include diet combined with physical activity interventions can reduce the risk of obesity (zBMI and BMI) in young children aged 0 to 5 years. There is weaker evidence from a single study that dietary interventions may be beneficial.However, interventions that focus only on physical activity do not appear to be effective in children of this age. In contrast, interventions that only focus on physical activity can reduce the risk of obesity (BMI) in children aged 6 to 12 years, and adolescents aged 13 to 18 years. In these age groups, there is no evidence that interventions that only focus on diet are effective, and some evidence that diet combined with physical activity interventions may be effective. Importantly, this updated review also suggests that interventions to prevent childhood obesity do not appear to result in adverse effects or health inequalities.The review will not be updated in its current form. To manage the growth in RCTs of child obesity prevention interventions, in future, this review will be split into three separate reviews based on child age.

School-Based Intervention on Cardiorespiratory Fitness in Brazilian Students: A Nonrandomized Controlled Trial

BACKGROUND

In response to the worldwide increasing prevalence of low cardiorespiratory fitness (CRF), several interventions have been developed. The aim of this study was to examine the effect of a school-based intervention on CRF in Brazilian students.

METHODS

A nonrandomised controlled design tested 432 students (intervention group: n = 247) from 6th to 9th grade recruited from two public secondary schools in Florianopolis, in 2015. The intervention entitled "MEXA-SE" (move yourself), applied over 13 weeks, included four components: (1) increases in physical activity during Physical Education classes; (2) active recess; (3) educational sessions; and (4) educational materials. CRF (20-m shuttle run test) was the primary outcome.

RESULTS

The effect size of the intervention on CRF was 0.15 (CI 95% = -0.04; 0.34). In the within-group comparisons, VO2max decreased significantly from baseline to follow-up in the control group but remained constant in the intervention group. After adjustment variables, differences between intervention and control group were not statistically significant (p > 0.05).

CONCLUSION

The "MEXA-SE" intervention did not have an effect on adolescents' CRF. However, maintenance of VO2max in intervention group and a reduction within control group demonstrates that this intervention may be beneficial for long-term CRF and, possibly, the increased intervention time could result in a better effect.

EFFECTIVENESS OF OBESITY INTERVENTION PROGRAMS BASED ON GUIDELINES FOR ADOLESCENT STUDENTS: SYSTEMATIC REVIEW

OBJECTIVE

To verify the effectiveness of educational interventions based on guidance on physical activity and nutrition in schoolchildren.

DATA SOURCES

A systematic search was carried out in four electronic databases containing articles published between October 2007 and January 2017 and addressing educational interventions with emphasis on both nutritional education and physical activity in schoolchildren and adolescents aged 10 to 19 years.

DATA SYNTHESIS

Twelve articles were selected for this review, of which four included only educational interventions; four made and association between educational interventions, inclusion of healthy foods and physical activity; two made a relation between guidelines and physical activity; and finally, two associated guidelines with consumption of healthy foods.

CONCLUSIONS

Interventions based on physical activity and/or nutrition counseling were efficient and showed superior results in studies that associated the practice of physical activity with counseling. However, the need for new studies on educational interventions among schoolchildren and adolescents was made evident.

Comparison between different criteria for metabolic syndrome in schoolchildren from southern Brazil

The metabolic syndrome (MetS), although more frequent in adults, is already evident in the infant-juvenile population. On the other hand, there are different criteria for the diagnosis, without a consensus of which is the best to be used in this population. The aim of this study was to evaluate the agreement between different criteria for diagnosis of MetS in adolescents from southern Brazil. A cross-sectional study consisting of a sample of 1200 subjects, 679 females, aged between 12 and 17 years. MetS was assessed by three different criteria: Cook (2003), Ferranti (2004), and International Diabetes Federation - IDF (2007). The agreement between the criteria was evaluated by the Kappa index. Low prevalence of MetS was found among schoolchildren (1.9% for Cook, 5.0% for Ferranti, and 2.1% for IDF). Regular (Ferranti - IDF: Kappa 0.382; p < 0.001) and moderate (Cook - Ferranti: Kappa 0.542; p < 0.001; Cook - IDF: Kappa 0.532; p < 0.001) agreement was demonstrated between the criteria. Elevated blood pressure was the most frequent condition in all the criteria, and the least frequent condition was in the glycemia (Cook and Ferranti) and high-density lipoprotein cholesterol levels.

CONCLUSION

The low prevalence of MetS and the low agreement among the existing criteria suggest the elaboration of new criteria for the diagnosis of MetS in the child and adolescent population. What is Known: • There are different criteria for the diagnosis of the metabolic syndrome (MetS), without a consensus of which is the best to be used in the infant-juvenile population. What is New: • Low prevalence of MetS identified among schoolchildren and the low agreement among the existing criteria suggest the elaboration of new criteria for the diagnosis of MetS in the child and adolescent population.

Characteristics of Teacher Training in School-Based Physical Education Interventions to Improve Fundamental Movement Skills and/or Physical Activity: A Systematic Review

BACKGROUND

Fundamental movement skill (FMS) competence is positively associated with physical activity (PA). However, levels of both FMS and PA are lower than expected. Current reviews of interventions to improve FMS and PA have shown that many school-based programs have achieved positive outcomes, yet the maintenance of these interventions is variable. Teachers play a central role in the success and longevity of school-based interventions. Despite the importance of teacher engagement, research into the nature and quality of teacher training in school-based PA and FMS interventions has received little attention.

OBJECTIVE

The aim of this systematic review was to investigate the type and quantity of teacher training in school-based physical education PA and/or FMS interventions, and to identify what role teacher training had on the intervention outcome.

METHODS

A systematic search of eight electronic databases was conducted. Publication date restrictions were not implemented in any database, and the last search was performed on 1 March 2015. School physical education-based interventions facilitated by a school teacher, and that included a quantitative assessment of FMS competence and/or PA levels were included in the review.

RESULTS

The search identified 39 articles. Eleven of the studies measured FMS, 25 studies measured PA and three measured both FMS and PA. Nine of the studies did not report on any aspect of the teacher training conducted. Of the 30 studies that reported on teacher training, 25 reported statistically significant intervention results for FMS and/or PA. It appears that teacher training programs: are ≥ 1 day; provide comprehensive subject and pedagogy content; are framed by a theory or model; provide follow-up or ongoing support; and measure teacher satisfaction of the training, are more effective at improving student outcomes in FMS and/or PA. However, the provision of information regarding the characteristics of the teacher training was largely inadequate. Therefore, it was difficult to ascertain which teacher training characteristics were most important in relation to intervention effectiveness.

CONCLUSION

It is clear that whilst teachers are capable of making substantial improvements in student outcomes in PA and FMS, the findings of this review suggest the teacher training component of school-based PA and/or FMS interventions is not only under-reported but is under-studied, and, perhaps as a result, the value of teacher training is not widely understood. What remains unclear, due to poor reporting, is what role teacher training is having on these outcomes.

School-Based Interventions to Improve Cardiorespiratory Fitness in Adolescents: Systematic Review with Meta-analysis

BACKGROUND

School-based intervention can contribute to the promotion of cardiorespiratory fitness (CRF) in adolescents. However, it is neces sary to systematize how intervention strategies and the methodological characteristics of studies influence the effects of CRF interventions.

OBJECTIVE

A meta-analysis review of school-based intervention studies aimed at increasing CRF in adolescents (10-19 years of age) was conducted.

METHODS

A search for studies was conducted using the Medline, Web of Science, LILACS, PsycINFO, Embase, Scopus, SPORTDiscus and Cochrane databases and the reference lists of the selected studies. The peer selection process included consideration of school-based randomized or non-randomized controlled trials with a duration ≥12 weeks published in English, Portuguese or Spanish, and with some CRF measures. The methodological quality of the studies was also assessed. The standardized mean differences (SMDs) and 95 % confidence intervals (95 % CIs) were calculated as an effect measure.

RESULTS

Forty publications of 30 interventions were included in the review, and 25 of these were meta-analysed. The effects of CRF interventions were moderate and significant (SMD = 0.68, 95 % CI 0.45-0.90), with high heterogeneity (I (2) = 97 %). The effect size varied significantly according to the age group, sample size, intervention environment, strategies in experimental groups, CRF priority in the study, CRF test and indicator, session length, weekly frequency, intervention duration and presentation of results by sex.

CONCLUSION

Interventions in the school environment seem to have a positive effect on CRF among adolescents, but there is high heterogeneity between studies. Some intervention characteristics can explain better effects on CRF (e.g. exercise sessions in addition to physical education classes; primary focus on this outcome; combination of aerobic and resistance exercises; classes lasting ≥60 min; frequency of three times weekly; and intensity control).

The theory of expanded, extended, and enhanced opportunities for youth physical activity promotion

BACKGROUND

Physical activity interventions targeting children and adolescents (≤18 years) often focus on complex intra- and inter-personal behavioral constructs, social-ecological frameworks, or some combination of both. Recently published meta-analytical reviews and large-scale randomized controlled trials have demonstrated that these intervention approaches have largely produced minimal or no improvements in young people's physical activity levels.

DISCUSSION

In this paper, we propose that the main reason for previous studies' limited effects is that fundamental mechanisms that lead to change in youth physical activity have often been overlooked or misunderstood. Evidence from observational and experimental studies is presented to support the development of a new theory positing that the primary mechanisms of change in many youth physical activity interventions are approaches that fall into one of the following three categories: (a) the expansion of opportunities for youth to be active by the inclusion of a new occasion to be active, (b) the extension of an existing physical activity opportunity by increasing the amount of time allocated for that opportunity, and/or (c) the enhancement of existing physical activity opportunities through strategies designed to increase physical activity above routine practice. Their application and considerations for intervention design and interpretation are presented. The utility of these mechanisms, referred to as the Theory of Expanded, Extended, and Enhanced Opportunities (TEO), is demonstrated in their parsimony, logical appeal, support with empirical evidence, and the direct and immediate application to numerous settings and contexts. The TEO offers a new way to understand youth physical activity behaviors and provides a common taxonomy by which interventionists can identify appropriate targets for interventions across different settings and contexts. We believe the formalization of the TEO concepts will propel them to the forefront in the design of future intervention studies and through their use, lead to a greater impact on youth activity behaviors than what has been demonstrated in previous studies.

Novel measures of inflammation and insulin resistance are related to obesity and fitness in a diverse sample of 11-14 year olds: The HEALTHY Study

Background

GlycA is a novel serum marker of systemic inflammation. There is no information on GlycA in pediatric populations, how it differs by gender or its association with body mass index (BMI) or fitness. LP-IR is a serum measure of insulin resistance which is related to changes in BMI group in adolescents, but its relationship with fitness is unknown. The current study examined the independent associations between fitness and BMI with GlycA and LP-IR among US adolescents.

Methods

Participants were 1664 US adolescents from the HEALTHY study with complete 6^th and 8^th grade BMI, fitness and blood data. GlycA and LP-IR were measured by NMR spectroscopy. Three BMI groups and three fitness groups were created. Linear mixed models examined associations between GlycA, LP-IR, fitness and BMI.

Results

LP-IR decreased between 6^th and 8^th grade. GlycA increased among girls but decreased among boys. At 8^th grade, median GlycA values were 27 (7.6%) μmol/L higher (381 versus 354) for girls than boys. Median GlycA 6^th grade values were 9% higher in obese girls than healthy weight girls. Overall there was strong evidence (p<0.001) that GlycA was higher in higher BMI groups. Fitness was negatively associated with GlycA (r = −0.37 and −0.35) and LP-IR (r = −0.34 and − 0.18) at the 6^th and 8^th grade assessments. As BMI category increased and fitness category decreased, GlycA and LP-IR levels increased. Lowest GlycA was found in the low BMI/high fitness group.

Conclusions

GlycA was associated with BMI and fitness among in US adolescents. These findings suggest that there are independent effects for BMI and fitness group with both GlycA and LP-IR. Future studies should validate the role of GlycA and LP-IR to evaluate the effects of interventions to modify obesity and fitness in order to improve systemic inflammation and insulin resistance.

Two years of school-based intervention program could improve the physical fitness among Ecuadorian adolescents at health risk: subgroups analysis from a cluster-randomized trial

Background

Adolescents with overweight and poor physical fitness have an increased likelihood of developing cardiovascular diseases during adulthood. In Ecuador, a health promotion program improved the muscular strength and speed-agility, and reduced the decline of the moderate-to-vigorous physical activity of adolescents after 28 months. We performed a sub-group analysis to assess the differential effect of this intervention in overweight and low-fit adolescents.

Methods

We performed a cluster-randomized pair matched trial in schools located in Cuenca–Ecuador. In total 20 schools (clusters) were pair matched, and 1440 adolescents of grade 8 and 9 (mean age of 12.3 and 13.3 years respectively) participated in the trial. For the purposes of the subgroup analysis, the adolescents were classified into groups according to their weight status (body mass index) and aerobic capacity (scores in the 20 m shuttle run and FITNESSGRAM standards) at baseline. Primary outcomes included physical fitness (vertical jump, speed shuttle run) and physical activity (proportion of students achieving over 60 min of moderate–to-vigorous physical activity/day). For these primary outcomes, we stratified analysis by weight (underweight, normal BMI and overweight/obese) and fitness (fit and low fitness) groups. Mixed linear regression models were used to assess the intervention effect.

Results

The prevalence of overweight/obesity, underweight and poor physical fitness was 20.3 %, 5.8 % and 84.8 % respectively. A higher intervention effect was observed for speed shuttle run in overweight (β = −1.85 s, P = 0.04) adolescents compared to underweight (β = −1.66 s, P = 0.5) or normal weight (β = −0.35 s, P = 0.6) peers. The intervention effect on vertical jump was higher in adolescents with poor physical fitness (β = 3.71 cm, P = 0.005) compared to their fit peers (β = 1.28 cm, P = 0.4). The proportion of students achieving over 60 min of moderate-to-vigorous physical activity/day was not significantly different according to weight or fitness status.

Conclusion

Comprehensive school-based interventions that aim to improve diet and physical activity could improve speed and strength aspects of physical fitness in low-fit and overweight/obese adolescents.

Trial registration

Clinicaltrials.gov identifier NCT01004367. Registered October 28, 2009.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0588-8) contains supplementary material, which is available to authorized users.

Energy Balance 4 Kids with Play: Results from a Two-Year Cluster-Randomized Trial

BACKGROUND

Identifying sustainable approaches to improving the physical activity (PA) and nutrition environments in schools is an important public health goal. This study examined the impact of Energy Balance for Kids with Play (EB4K with Play), a school-based intervention developed by the Academy of Nutrition and Dietetics Foundation and Playworks, on students' PA, dietary habits and knowledge, and weight status over 2 years.

METHODS

This cluster-randomized, controlled trial took place in four intervention and two control schools over 2 years (n=879; third- to fifth-grade students). PA (fourth and fifth grades only), dietary knowledge and behaviors, school policies, and BMI z-score were assessed at baseline (fall 2011), midpoint (spring 2012), and endpoint (fall 2012 for accelerometers; spring 2013 for all other outcomes).

RESULTS

At endpoint, there were no group differences in change in PA or dietary behaviors, although BMI z-score decreased overall by -0.07 (p=0.05). Students' dietary knowledge significantly increased, as did the amount of vegetables schools served. Post-hoc analyses stratified by grade revealed that, relative to control students, fourth-grade intervention students reduced school-day sedentary time by 15 minutes (p=0.023) and third-grade intervention students reduced BMI z-score by -0.2 (0.05; p<0.05). There were no significant differences for older students.

CONCLUSIONS

EB4K with Play, which leverages the existing infrastructure of two national programs, increases children's dietary knowledge and may improve weight status and decrease sedentary behaviors among younger children. Future iterations should examine programming specific for different age groups.

Exercise intervention and cardiovascular risk factors in obese children. Comparison between obese youngsters taking part in a physical activity school-based programme with and without individualised diet counselling: the ACORDA project

AIM

To determine the effects of a school-based exercise intervention programme on cardiovascular risk factors, including body fat (BF), metabolic profile and physical activity (PA) in children with and without individualised dietary counselling approach (IDC and WIDC).

SUBJECTS AND METHODS

Forty-six overweight children from 6-16 years old (25 girls, 54.3%; age = 10.3 ± 2.8) of six schools took part in an 8-month interdisciplinary, school-based intervention programme. All children were engaged in PA classes, but only one group was exposed to individualised counselling. Blood pressure (BP), lipids and lipoproteins, accelerometer-based PA, percentage of body fat (%BF) and trunk fat (%TF) measures were taken before and after intervention. General Linear Model (Repeated Measures ANOVA) adjusted for age, maturation and height change was used to analyse the longitudinal effect of individualised counselling between two evaluations in each group.

RESULTS

Favourable changes were observed for %BF, %TF, systolic BP and total cholesterol in the IDC group. Subjects WIDC only increased light and moderate-vigorous PA. In IDC, significant effects for time * group interactions were found for systolic BP, total cholesterol and LDL-cholesterol, indicating that counselling might add favourable changes in these markers, beyond those explained by PA and growth.

CONCLUSION

School-based interventions can contribute to counteracting obesity in youth, particularly when individualised dietary counselling is provided. Therefore, the link between schools and professional counselling should be strengthened to ensure consolidated changes towards healthy behaviours.

Systematic review shows only few reliable studies of physical activity intervention in adolescents

Introduction. Several studies have pointed to the high prevalence of low levels of physical activity in adolescents, suggesting the need for more effective interventions for this group. The aim of this study was to present evidence of intervention programs for efficacy of physical activity for adolescents. Methods. Surveys in PubMed, SportDiscus, LiLacs, and SciELO databases were conducted using keywords to identify population, intervention, and outcome, as well as DeCS and MeSH terms in English, Portuguese, and Spanish, whenever appropriate. The review included observational studies with minimal intervention of six months, minimum sample size of 100 adolescents, written in any language, and those who have reached STROBE score greater than 70%. Results. Only seven studies met all inclusion criteria. Of these, five were pre- and postintervention and two had n > 2000 participants. Interventions were of several types, durations, and strategies for physical activity implementation. Behavior change was assessed in 43% of studies and three reported success in some way. Conclusion. Due to heterogeneity in their contents and methodologies, as well as the lack of jobs that accompany adolescents after the intervention period, one cannot draw conclusions about the actual effects of the intervention programs of physical activity on the behavior of young people.

Promotion of cardiovascular health at three stages of life: never too soon, never too late

Cardiovascular disease is the leading cause of death worldwide, with an especially devastating impact in low-to-medium income countries. Cardiovascular disease has been elevated to this position by a combination of factors that include urbanization and its attendant effects, such as obesity, a sedentary lifestyle, changes in dietary habits, and smoking. Given the enormous extent of the problem and the complexity of its causes, which include cultural, social, political, and health care factors, an equally sophisticated and comprehensive strategy is required to combat cardiovascular disease on a global scale. Because exposure to cardiovascular risk factors occurs from early ages, this strategy must be expanded and adjusted throughout the life of an individual. Thus, our efforts should be concentrated not only on cardiovascular disease treatment and prevention, but also on health promotion and primordial prevention. In this review, we present different strategies yielding encouraging results at the population level, from childhood until old age, that aim to protect against the challenges facing the scientific community when combating cardiovascular disease.

Effect of relative weight group change on nuclear magnetic resonance spectroscopy derived lipoprotein particle size and concentrations among adolescents

OBJECTIVE

To examine whether longitudinal changes in relative weight category (as indicated by change in body mass index [BMI] classification group) were associated with changes in nuclear magnetic resonance (NMR)-derived lipoprotein particles among US youth.

STUDY DESIGN

Secondary analysis of data from a clustered randomized controlled trial. BMI and fasting blood samples were obtained from 2069 participants at the start of the 6th grade and end of the 8th grade. BMI was categorized as normal weight, overweight, or obese at both time points. Lipoprotein particle profiles were measured with NMR spectroscopy at both time points. Regression models were used to examine changes in relative weight group and change in lipoprotein variables.

RESULTS

A total of 38% of participants changed relative weight category (BMI group) during the 2.5-year study period. Low-density lipoprotein (LDL) cholesterol and non-high-density lipoprotein (HDL) cholesterol decreased almost universally, but more with improved BMI category. There were adverse effects on LDL size and total LDL particles, HDL size, and cholesterol for participants who remained obese or whose relative weight group worsened. Changes in relative category had no impact on HDL particles.

CONCLUSION

Improvement in relative weight group from 6th to 8th grade was associated with favorable changes in non-HDL cholesterol, very low-density lipoprotein size, LDL size, HDL size, and LDL particles but had no effect on HDL particles. Findings indicate that an improvement in relative weight group between 6th and 8th grade had an effect on NMR-derived particles sizes and concentrations among a large group of adolescents, which overrepresented low-income minorities.

Do school-based physical activity interventions increase or reduce inequalities in health?

Little is known about the effectiveness of school-based health promotion on physical activity inequalities among children from low-income areas. This study compared the two-year change in physical activity among 10-11 year-old children attending schools with and without health promotion programs by activity level, body weight status, and socioeconomic backgrounds to assess whether health promotion programs reduce or exacerbate health inequalities. This was a quasi-experimental trial of a Comprehensive School Health (CSH) program implemented in schools located in socioeconomically disadvantaged neighbourhoods in Edmonton, Alberta, Canada. In the spring of 2009 and 2011, pedometer (7 full days) and demographic data were collected from cross-sectional samples of grade five children from 10 intervention and 20 comparison schools. Socioeconomic status was determined from parent self-report. Low-active, active, and high-active children were defined according to step-count tertiles. Multilevel linear regression methods adjusted for potential confounders were used to assess the relative inequity in physical activity and were compared between groups and over-time. In 2009, a greater proportion of students in the intervention schools were overweight (38% vs. 31% p = 0.03) and were less active (10,827 vs. 12,265 steps/day p < 0.001). Two years later, the relative difference in step-counts between intervention and comparison schools reduced from -15.5% to 0% among low-active students, from -13.4% to 0% among active students, and from -15.1% to -2.7% among high-active students. The relative difference between intervention and comparison schools reduced from -11.1% to -1.6% among normal weight students, from -16.8% to -1.4% among overweight students, and was balanced across socioeconomic subgroups. These findings demonstrate that CSH programs implemented in socioeconomically disadvantaged neighbourhoods reduced inequalities in physical activity. Investments in school-based health promotion are a viable, promising, and important approach to improve physical activity and prevent childhood obesity, and may also reduce inequalities in health.

The WHO Health Promoting School framework for improving the health and well-being of students and their academic achievement

BACKGROUND

The World Health Organization's (WHO's) Health Promoting Schools (HPS) framework is an holistic, settings-based approach to promoting health and educational attainment in school. The effectiveness of this approach has not been previously rigorously reviewed.

OBJECTIVES

To assess the effectiveness of the Health Promoting Schools (HPS) framework in improving the health and well-being of students and their academic achievement.

SEARCH METHODS

We searched the following electronic databases in January 2011 and again in March and April 2013: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, CINAHL, Campbell Library, ASSIA, BiblioMap, CAB Abstracts, IBSS, Social Science Citation Index, Sociological Abstracts, TRoPHI, Global Health Database, SIGLE, Australian Education Index, British Education Index, Education Resources Information Centre, Database of Education Research, Dissertation Express, Index to Theses in Great Britain and Ireland, ClinicalTrials.gov, Current controlled trials, and WHO International Clinical Trials Registry Platform. We also searched relevant websites, handsearched reference lists, and used citation tracking to identify other relevant articles.

SELECTION CRITERIA

We included cluster-randomised controlled trials where randomisation took place at the level of school, district or other geographical area. Participants were children and young people aged four to 18 years, attending schools or colleges. In this review, we define HPS interventions as comprising the following three elements: input to the curriculum; changes to the school's ethos or environment or both; and engagement with families or communities, or both. We compared this intervention against schools that implemented either no intervention or continued with their usual practice, or any programme that included just one or two of the above mentioned HPS elements.

DATA COLLECTION AND ANALYSIS

At least two review authors identified relevant trials, extracted data, and assessed risk of bias in the trials. We grouped different types of interventions according to the health topic targeted or the approach used, or both. Where data permitted, we performed random-effects meta-analyses to provide a summary of results across studies.

MAIN RESULTS

We included 67 eligible cluster trials, randomising 1443 schools or districts. This is made up of 1345 schools and 98 districts. The studies tackled a range of health issues: physical activity (4), nutrition (12), physical activity and nutrition combined (18), bullying (7), tobacco (5), alcohol (2), sexual health (2), violence (2), mental health (2), hand-washing (2), multiple risk behaviours (7), cycle-helmet use (1), eating disorders (1), sun protection (1), and oral health (1). The quality of evidence overall was low to moderate as determined by the GRADE approach. 'Risk of bias' assessments identified methodological limitations, including heavy reliance on self-reported data and high attrition rates for some studies. In addition, there was a lack of long-term follow-up data for most studies.We found positive effects for some interventions for: body mass index (BMI), physical activity, physical fitness, fruit and vegetable intake, tobacco use, and being bullied. Intervention effects were generally small but have the potential to produce public health benefits at the population level. We found little evidence of effectiveness for standardised body mass index (zBMI) and no evidence of effectiveness for fat intake, alcohol use, drug use, mental health, violence and bullying others; however, only a small number of studies focused on these latter outcomes. It was not possible to meta-analyse data on other health outcomes due to lack of data. Few studies provided details on adverse events or outcomes related to the interventions. In addition, few studies included any academic, attendance or school-related outcomes. We therefore cannot draw any clear conclusions as to the effectiveness of this approach for improving academic achievement.

AUTHORS' CONCLUSIONS

The results of this review provide evidence for the effectiveness of some interventions based on the HPS framework for improving certain health outcomes but not others. More well-designed research is required to establish the effectiveness of this approach for other health topics and academic achievement.

Treadmill workstations: the effects of walking while working on physical activity and work performance

We conducted a 12-month-long experiment in a financial services company to study how the availability of treadmill workstations affects employees' physical activity and work performance. We enlisted sedentary volunteers, half of whom received treadmill workstations during the first two months of the study and the rest in the seventh month of the study. Participants could operate the treadmills at speeds of 0-2 mph and could use a standard chair-desk arrangement at will. (a) Weekly online performance surveys were administered to participants and their supervisors, as well as to all other sedentary employees and their supervisors. Using within-person statistical analyses, we find that overall work performance, quality and quantity of performance, and interactions with coworkers improved as a result of adoption of treadmill workstations. (b) Participants were outfitted with accelerometers at the start of the study. We find that daily total physical activity increased as a result of the adoption of treadmill workstations.

Six physical education lessons a week can reduce cardiovascular risk in school children aged 6-13 years: a longitudinal study

AIMS

Cardiovascular disease (CVD) originates during childhood and adolescence. Schools are potentially effective settings for early public health prevention strategies. The aim of this study was to evaluate the effect of six physical education (PE) lessons on children's CVD risk.

METHODS

This longitudinal study in 10 public schools (1218 children, aged 6-13 years), 6 intervention and 4 control schools evaluates a natural experiment, where intervention schools tripled PE to six lessons per week compared to the mandatory two PE lessons in the control schools. Baseline (2008) and 2-year follow-up measures were anthropometrics, cardiorespiratory fitness, blood pressure and blood samples providing lipids and measures for insulin resistance. Based on these variables, a composite risk score was calculated and used for further analysis. Multivariate multilevel mixed effect regression models were used to estimate effect of intervention taking the hierarchical structure of data into account. Individual, class and school were considered random effects. Intra class correlation (ICC) was calculated.

RESULTS

Intervention significantly lowered mean of composite risk score with 0.17 SD (95% CI: -0.34 to -0.01). Six PE lessons per week had a beneficial effect on triglycerides (TG) levels (-0.18 SD, 95% CI: -0.36 to 0.00), systolic blood pressure (SBP) (-0.22 SD, 95% CI: -0.42 to -0.02) and insulin resistance (HOMA-IR) (-0.17 SD, 95% CI: -0.34 to 0.01).

CONCLUSIONS

Six PE lessons at school can reduce children's CVD risk measured as a composite risk score. The changes in risk score are considered substantial in the perspective of public health strategy for preventing CVD in later life.

Lessons learned from the HEALTHY primary prevention trial of risk factors for type 2 diabetes in middle school youth

The HEALTHY trial was designed to take a primary prevention approach to risk factors for type 2 diabetes in youth, primarily obesity. The study involved over 6,000 students at 42 middle schools across the U.S. Half received an integrated intervention program of components addressing the school food environment, physical education, lifestyle behaviors, and promotional messaging. The intervention was designed to be more comprehensive than previous efforts, and the research was amply funded. Although the primary objective of reducing the percentage of overweight and obesity in schools that received the intervention program, as compared with control schools, was not obtained, key secondary outcomes indicated an intervention effect. In retrospect, senior investigators involved in the study's design, conduct, and analysis discuss weaknesses and strengths and offer recommendations for future research efforts that address prevention of childhood obesity from a public health perspective.

BMI change, fitness change and cardiometabolic risk factors among 8th grade youth

This paper examined whether a two-year change in fitness, body mass index (BMI) or the additive effect of change in fitness and BMI were associated with change in cardiometabolic risk factors among youth. Cardiometabolic risk factors, BMI group (normal weight, overweight or obese) were obtained from participants at the start of 6th grade and end of 8th grade. Shuttle run laps were assessed and categorized in quintiles at both time points. Regression models were used to examine whether changes in obesity, fitness or the additive effect of change in BMI and fitness were associated with change in risk factors. There was strong evidence (p < .001) that change in BMI was associated with change in cardiometabolic risk factors. There was weaker evidence of a fitness effect, with some evidence that change in fitness was associated with change in total cholesterol, HDL-C, LDL-C and clustered risk score among boys, as well as HDL-C among girls. Male HDL-C was the only model for which there was some evidence of a BMI, fitness and additive BMI*fitness effect. Changing body mass is central to the reduction of youth cardiometabolic risk. Fitness effects were negligible once change in body mass had been taken into account.

Gamified physical activation of young men--a Multidisciplinary Population-Based Randomized Controlled Trial (MOPO study)

BACKGROUND

Inactive and unhealthy lifestyles are common among adolescent men. The planned intervention examines the effectiveness of an interactive, gamified activation method, based on tailored health information, peer networks and participation, on physical activity, health and wellbeing in young men. We hypothesize that following the intervention the physical activation group will have an improved physical activity, as well as self-determined and measured health compared with the controls.

METHODS/DESIGN

Conscription-aged men (18 years) attending compulsory annual call-ups for military service in the city of Oulu in Finland (n = 1500) will be randomized to a 6-months intervention (n = 640) or a control group (n = 640) during the fall 2013. A questionnaire on health, health behaviour, diet and wellbeing is administered in the beginning and end of the intervention. In addition, anthropometric measures (height, weight and waist circumference), body composition, grip strength, heart rate variability and aerobic fitness will be measured. The activation group utilizes an online gamified activation method in combination with communal youth services, objective physical activity measurement, social networking, tailored health information and exercise programs according to baseline activity level and the readiness of changes of each individual. Daily physical activity of the participants is monitored in both the activation and control groups. The activation service rewards improvements in physical activity or reductions in sedentary behaviour. The performance and completion of the military service of the participants will also be followed.

DISCUSSION

The study will provide new information of physical activity, health and health behaviour of young men. Furthermore, a novel model including methods for increasing physical activity among young people is developed and its effects tested through an intervention. This unique gamified service for activating young men can provide a translational model for community use. It can also be utilized as such or tailored to other selected populations or age groups.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01376986.

Population approaches to improve diet, physical activity, and smoking habits: a scientific statement from the American Heart Association

BACKGROUND

Poor lifestyle behaviors, including suboptimal diet, physical inactivity, and tobacco use, are leading causes of preventable diseases globally. Although even modest population shifts in risk substantially alter health outcomes, the optimal population-level approaches to improve lifestyle are not well established.

METHODS AND RESULTS

For this American Heart Association scientific statement, the writing group systematically reviewed and graded the current scientific evidence for effective population approaches to improve dietary habits, increase physical activity, and reduce tobacco use. Strategies were considered in 6 broad domains: (1) Media and educational campaigns; (2) labeling and consumer information; (3) taxation, subsidies, and other economic incentives; (4) school and workplace approaches; (5) local environmental changes; and (6) direct restrictions and mandates. The writing group also reviewed the potential contributions of healthcare systems and surveillance systems to behavior change efforts. Several specific population interventions that achieved a Class I or IIa recommendation with grade A or B evidence were identified, providing a set of specific evidence-based strategies that deserve close attention and prioritization for wider implementation. Effective interventions included specific approaches in all 6 domains evaluated for improving diet, increasing activity, and reducing tobacco use. The writing group also identified several specific interventions in each of these domains for which current evidence was less robust, as well as other inconsistencies and evidence gaps, informing the need for further rigorous and interdisciplinary approaches to evaluate population programs and policies.

CONCLUSIONS

This systematic review identified and graded the evidence for a range of population-based strategies to promote lifestyle change. The findings provide a framework for policy makers, advocacy groups, researchers, clinicians, communities, and other stakeholders to understand and implement the most effective approaches. New strategic initiatives and partnerships are needed to translate this evidence into action.

Bristol girls dance project feasibility trial: outcome and process evaluation results

Background

Many adolescent girls do not engage in sufficient physical activity (PA). This study examined the feasibility of conducting a cluster randomized controlled trial (RCT) to evaluate an after-school dance program to increase PA among 11–12 year old girls in Bristol, UK.

Methods

Three-arm, cluster RCT. Three secondary schools were assigned to intervention arm. Intervention participants received a 9-week dance program with 2, 90-minute dance classes per week. Participants at 2 control schools received incentives for data collection. Participants at 2 additional control schools received incentives and a delayed dance workshop. Accelerometer data were collected at baseline (time 0), during the last week of the dance program (time 1) and 20 weeks after the start of the study (time 2). Weekly attendance, enjoyment and perceived exertion were assessed in intervention participants. Post-study qualitative work was conducted with intervention participants and personnel.

Results

40.1% of girls provided consent to be in the study. The mean number of girls attending at least one dance session per week ranged from 15.4 to 25.9. There was greater number of participants for whom accelerometer data were collected in control arms. The mean attendance was 13.3 sessions (maximum = 18). Perceived exertion ratings indicated that the girls did not find the sessions challenging. The dance teachers reported that the program content would benefit from revisions including less creative task time, a broader range of dance genres and improved behavioral management policies. At time 2, the 95% confidence intervals suggest between 5 and 12 minutes more weekday MVPA in the intervention group compared with the control incentives only group, and between 6 minutes fewer and 1 minute more compared with the control incentives plus workshop group. Between 14 and 24 schools would be required to detect a difference of 10 minutes in mean weekday MVPA between intervention and control groups.

Conclusions

It is possible to recruit 11–12 year old girls to participate in an after-school dance study. An after-school dance intervention has potential to positively affect the PA levels of 11–12 year old girls but an adequately powered RCT is required to test this intervention approach.