Physical activity interventions in the prevention and treatment of paediatric obesity: systematic review and critical appraisal

Effectiveness of utilizing step-monitoring devices to prevent and treat obesity in children and adolescents: A systematic review and meta-analysis

Background

Children and adolescents who are overweight and obese represent a growing public health issue. The use of step-monitoring devices as an intervention tool may be a simple, cost-effective, and easily replicable solution for addressing obesity in children and adolescents. No prior systematic reviews have evaluated the effectiveness of utilizing step-monitoring devices as an intervention method for obesity in children and adolescents.

Methods

Previous studies on using step-monitoring devices to prevent and treat obesity in children and adolescents were identified in the following databases: Web of Science, EMBASE, PubMed, Cochrane Library, SPORTDiscus, and SCOPUS. The search period for each database ranged from the year of their inception to 8 March 2023 (updated in June 2024). Meta-analyses were performed for mean differences (MDs) in body mass index (BMI), BMI z-score (BMI-Z), body fat, waist circumference, and body weight.

Results

From 12,907 relevant records, 23 studies were included in this meta-analysis. The included studies were mainly at low risk of bias, except for blinding. Step-monitoring device-based interventions had significant effects in reducing BMI-Z (MD -0.06; 95% CI -0.10 to -0.02), body fat (MD -0.95%; 95% CI -1.35 to -0.54), and body weight (MD -1.23 kg; 95% CI -2.36 to -0.10). However, there was no significant effect on BMI (MD -0.16 kg/m2; 95% CI -0.55 to 0.22) and waist circumference (MD -0.33 cm; 95% CI -1.23 to 0.58). Subgroup analyses indicated that participants who were overweight or obese showed greater intervention effects on BMI and BMI-Z compared to participants with normal weight. The programs with an intervention duration of ≤6 months presented a greater intervention effect on BMI-Z than those with an intervention duration of more than 6 months. The programs that established goals had a greater intervention effect on body fat than those that did not.

Conclusions

Step-monitoring devices may be an effective and generalizable intervention tool for the prevention and treatment of obesity in children and adolescents. Future studies should further explore how to set step goals and the duration of interventions to achieve better intervention effects.

Effect of Dietary Modification and Physical Activity on Obese Young Adults Going to Gym for Weight Loss in Central India: A Before and After Study

BACKGROUND

An adequate diet is a prerequisite for appropriate growth and development so as to remain active. Balanced nutrition coupled with physical activity forms a healthy lifestyle which eventually leads to multiple health benefits such as positive mental health and a lower risk of noncommunicable diseases like diabetes, hypertension, etc. It has become an upcoming trend for young adults to join a gym. In order to maintain weight members, go to the gym because they consider it as a positive opportunity to boost self-esteem and to make appropriate health decisions to feel better. There is a need to highlight with the help of research studies that lifestyle modification in the form of diet and physical activity on a regular basis can help in controlling obesity.

METHODS

A before and after the study was carried out in Nagpur city located in Central India for a period of 8 months (April 1, 2022 to November 30, 2022). The study subjects were obese young adults going to the gym in Nagpur city. Diet and physical activity interventions were given for a duration of three months to the study subjects. The study instrument was a predesigned and pretested questionnaire.

RESULTS

In the present study, total 110 study subjects responded by completely filling out the questionnaire The total calorie and protein intake of the study subjects before and after giving intervention for three months was found to be highly significant (p-value < 0.0001). The change in mean anthropometric parameters of the study subjects before and after giving intervention for three months was found to be highly significant (p-value < 0.0001).

CONCLUSIONS

Dietary modification combined with physical activity for an average of 75 minutes is the most effective short-term intervention for weight loss. The present study concludes that lifestyle modifications can reverse the trend of obesity. It is reversible, and obese individuals can normalize their BMI with appropriate interventions as was performed with the present obese study subjects.

Influencing factors of children's physical activity in family

BACKGROUND

Children's physical activity (PA) is an important guarantee for children's physical and mental health. Influencing factors of children's PA in family is related to the healthy growth of children and the happy life of families.

METHODS

This is a cross-sectional study of influencing factors of children's PA in family. Parents whose children in 15 kindergartens(i.e., children are aged from 3 to 6 years) were sampled.

RESULTS

Government had a significant negative impact on parents' perceived risks. Community has a significant positive effect on parents' perceived benefits and a significant negative effect on parents' perceived risks. Kindergarten has a significant positive effect on parents' perceived benefits, but has no significant effect on the parents' perceived risks. Children sports club has a significant positive effect on parents' perceived benefits. Parents' perceived benefits has a significant positive impact on children's PA in family, while perceived risks has a significant negative impact.

CONCLUSION

Government should play a leading role in the development of children's PA in family. Community provides supplementary support. Kindergarten is the key point of developing children's PA in family. Children sports club is the auxiliary force of children's PA in family.

Does Motivational Interviewing Improve the Weight Management Process in Adolescents? A Systematic Review and Meta-analysis

BACKGROUND

Due to the complex nature and high heterogeneity of motivational interviewing (MI) trials, available data on the effectiveness of these interventions on weight management in the early years of life is not yet conclusive. This study aimed to (1) evaluate the effectiveness of MI-based interventions on modifying obesity-related behaviors and consequently controlling weight in adolescents, and (2) determine characteristics of participants and interventions through sub-group analysis.

METHODS

Electronic databases, i.e., Medline, Elsevier, ISI, Cochrane Central Register of Controlled Trials (Clinical Trials), PsycINFO, and subject-related key journals were searched for randomized controlled trials that investigated the effect of MI-based interventions on weight management in overweight/obese adolescents. Primary outcomes were BMI, BMI Z-score, waist circumference, and fat percentage. Secondary outcomes were related behaviors (dietary intake and physical activity) and cognitive abilities (self-efficacy, self-regulation, self-control). Of the 3673 studies initially screened for eligibility, nineteen studies met the inclusion criteria and eighteen studies were entered in the meta-analysis. Meta-regression and sub-group analyses were conducted to control the high heterogeneity of studies. Sensitivity analysis has been conducted based on the Cochrane guidelines using the leave-one-out methods.

RESULTS

MI-based interventions did not affect on all primary outcomes, including BMI, BMI Z-score, waist circumference, and fat percentage; however, in terms of secondary outcomes, only sugary beverage intake was reduced in adolescents (SMD =  - 0.47, K = 3, I² = 26.2%). Physical activity and cognitive variables were not considered in the current analysis due to limited data and high heterogeneity in measurements and reports. In addition, findings of sensitivity results showed that MI could significantly reduce waist circumference among adolescents (SMD =  - 0.51, 95% CI - 0.91 to - 0.11). In terms of subgroup analysis, our results showed that various characteristics of participants (age, sex, weight status) and interventions (parental involvement, study duration, fidelity assessment, type of the control groups) could affect related primary and secondary outcomes among adolescents.

CONCLUSION

MI-based behavioral interventions had minor effects on reducing sugary beverage intake in all adolescents while a reduction in central obesity was noted predominantly among girls and those with complete participation. The current results indicate that the main characteristics influencing goal achievement in MI interventions are the age of participants, MI fidelity assessment, parental involvement, duration of interventions, and type of the control groups.

Classroom-based physical activity and math performance: Integrated physical activity or not?

AIM

This 8-week intervention examined the effect of two different types of classroom-based physical activity on math performance in elementary school children.

METHODS

Students in 4th and 5th grade (N = 560; 32 classes, 9-11 years old) from six schools were assigned to integrated physical activity (Move for Thought [M4T], n = 221), activity break (AB; n = 134) and a control group (n = 205; usual instruction) for eight weeks. Students completed a standardised math test before and after the intervention. Programme fidelity was measured with a teacher daily log, recording the duration and frequency of the physical activity sessions. Linear mixed models were used for the analyses. Grade and gender were explored as moderators.

RESULTS

Move for Thought group outperformed AB (p < 0.001, d = 0.44) and control groups (p = 0.013, d = 0.38). However, subgroup analyses showed that these effects were evident only in Grade 4. No gender differences were found. Intervention fidelity showed that the classroom-based physical activities (M4T and AB) were used about every other day, with higher implementation among 4th graders.

CONCLUSION

This study indicated that integrating physical activity with mathematics has stronger effects on mathematics than activity breaks and traditional instruction.

Changing activity behaviours in vocational school students: the stepwise development and optimised content of the 'let's move it' intervention

Background: School-based interventions that increase physical activity (PA) in a sustainable way are lacking. Systematic and participatory, theory and evidence-based intervention development may enhance the effectiveness of complex behavioural interventions in the long term. However, detailed descriptions of the intervention development process are rarely openly published, hindering transparency and progress in the field. Aims: To illustrate a stepwise process to develop intervention targeting PA and sedentary behaviour (SB) among older adolescents, and to describe the final, optimised version of the intervention, detailing content of sessions by theoretical determinants and techniques. Methods: Two established intervention development frameworks (Intervention Mapping and Behaviour Change Wheel) were integrated, leading to a comprehensive evidence and theory-based process. It was informed by empirical studies, literature reviews, expert and stakeholder consultation, including scenario evaluation and component pre-testing. In all steps, contextual fit and potential for sustainability were ensured by stakeholder engagement. Results: As a large majority of youth opposed decreasing screen time, increasing PA and decreasing SB were defined as target behaviours, with peers and the school context including classroom practices as key social environments in influencing youth PA (problem specification, step 1). Behavioural diagnosis (step 2) identified a variety of determinants in the domains of capability (e.g. self-regulation skills), motivation (e.g. outcome expectations) and environmental opportunities. These were organised into an intervention theory integrating several formal theories, including Self-Determination Theory. Theory-aligned principles guided material design (Step 3). Feasibility RCT allowed optimisation into a final intervention protocol (step 4). Conclusions: Intervention elements target students directly, and indirectly by changing teacher behaviour and the school and wider environment. A systematic development and optimisation led to a high potential for sustainability. The detailed intervention content, with specification of the hypothesised mechanisms, allows for other researchers to replicate, adapt or refine parts or the whole intervention, considering specific target groups and (sub-)cultures.

Identification and evaluation of risk of generalizability biases in pilot versus efficacy/effectiveness trials: a systematic review and meta-analysis

BACKGROUND

Preliminary evaluations of behavioral interventions, referred to as pilot studies, predate the conduct of many large-scale efficacy/effectiveness trial. The ability of a pilot study to inform an efficacy/effectiveness trial relies on careful considerations in the design, delivery, and interpretation of the pilot results to avoid exaggerated early discoveries that may lead to subsequent failed efficacy/effectiveness trials. "Risk of generalizability biases (RGB)" in pilot studies may reduce the probability of replicating results in a larger efficacy/effectiveness trial. We aimed to generate an operational list of potential RGBs and to evaluate their impact in pairs of published pilot studies and larger, more well-powered trial on the topic of childhood obesity.

METHODS

We conducted a systematic literature review to identify published pilot studies that had a published larger-scale trial of the same or similar intervention. Searches were updated and completed through December 31st, 2018. Eligible studies were behavioral interventions involving youth (≤18 yrs) on a topic related to childhood obesity (e.g., prevention/treatment, weight reduction, physical activity, diet, sleep, screen time/sedentary behavior). Extracted information included study characteristics and all outcomes. A list of 9 RGBs were defined and coded: intervention intensity bias, implementation support bias, delivery agent bias, target audience bias, duration bias, setting bias, measurement bias, directional conclusion bias, and outcome bias. Three reviewers independently coded for the presence of RGBs. Multi-level random effects meta-analyses were performed to investigate the association of the biases to study outcomes.

RESULTS

A total of 39 pilot and larger trial pairs were identified. The frequency of the biases varied: delivery agent bias (19/39 pairs), duration bias (15/39), implementation support bias (13/39), outcome bias (6/39), measurement bias (4/39), directional conclusion bias (3/39), target audience bias (3/39), intervention intensity bias (1/39), and setting bias (0/39). In meta-analyses, delivery agent, implementation support, duration, and measurement bias were associated with an attenuation of the effect size of - 0.325 (95CI - 0.556 to - 0.094), - 0.346 (- 0.640 to - 0.052), - 0.342 (- 0.498 to - 0.187), and - 0.360 (- 0.631 to - 0.089), respectively.

CONCLUSIONS

Pre-emptive avoidance of RGBs during the initial testing of an intervention may diminish the voltage drop between pilot and larger efficacy/effectiveness trials and enhance the odds of successful translation.

Effects of Exergaming on Preschoolers' Executive Functions and Perceived Competence: A Pilot Randomized Trial

Purpose: This study aimed to evaluate the effects of a child-centered exergaming program and a traditional teacher-led physical activity (PA) program on preschoolers’ executive functions and perceived competence. Methods: Sixty children aged 4–5 years from an urban childcare center in China completed an 8-week exergaming/traditional PA intervention. After baseline measurements of executive functions and perceived competence (i.e., perceived physical competence and social acceptance), children were randomly assigned to either an exergaming group or traditional PA group (30 children per group). Exergaming and traditional PA programs were offered 20 min/session by trained instructors for 8 weeks. Post-intervention measures were identical to baseline measures. Results: In general, children’s executive functions, perceived physical competence, and perceived social acceptance were enhanced over time. Analysis of variance revealed significant time by group interaction effects for executive functions, F(1, 58) = 12.01, p = 0.01, and perceived social acceptance, F(1, 58) = 6.04, p = 0.02, indicating that the exergaming intervention group displayed significantly greater increases in executive functions and perceived social acceptance in comparison with traditional PA children. In addition, children’s executive functions and perceived physical and social competence significantly improved from baseline to post-intervention. However, there was no significant difference in the increase of children’s perceived physical competence across groups over time. Conclusion: The results suggested exergaming to be beneficial in enhancing young children’s executive functions and perceived social acceptance compared to the traditional PA program. More diverse samples with a longer intervention duration in preschool children in urban areas are warranted.

Effects of exergaming on motor skill competence, perceived competence, and physical activity in preschool children

BACKGROUND

Few school settings offer opportunities for preschool children to engage in structured physical activity, and only a few studies have been conducted examining exergaming's effectiveness on health outcomes in this age group. This study's purpose, therefore, was to examine a school-based exergaming intervention's effect on preschool children's perceived competence (PC), motor skill competence (MSC), and physical activity versus usual care (recess), as well as to examine gender differences for these outcomes.

METHODS

A total of 65 preschool children from 2 underserved urban schools were assigned to 1 of 2 conditions, with the school as the experimental unit: (1) usual care recess group (8 weeks of 100min of recess/week (5 days × 20 min)) and (2) exergaming intervention group (8 weeks of 100min of exergaming/week (5 days × 20 min) at school). All children underwent identical assessments of PC, MSC, and moderate-to-vigorous physical activity (MVPA) at baseline and at the end of the 8th week.

RESULTS

A significant Group × Time effect was observed for MVPA, F(1, 52) = 4.37, p = 0.04, η p 2  = 0.04, but not for PC, F(1, 52) = 0.83, p = 0.37, η p 2  = 0.02, or MSC, F(1, 52) = 0.02, p = 0.88, η p 2  = 0.00. Specifically, the intervention children displayed significantly greater increased MVPA after 8weeks than the comparison children. Additionally, there was a significant time effect for MSC, F(1, 52) = 15.61, p < 0.01, η p 2  = 0.23, and gender effect for MVPA, F(1, 52) = 5.06, p = 0.02, η p 2  = 0.09. Although all preschoolers' MSC improved across time, boys demonstrated greater MVPA than girls at both time points.

CONCLUSION

Exergaming showed a positive effect in promoting preschool children's MVPA at school and has the potential to enhance PC and MSC. More research with larger sample sizes and longer study durations are warranted.

Reward sensitivity and body weight: the intervening role of food responsive behavior and external eating

BACKGROUND

During the last three decades, the prevalence of childhood overweight and obesity has increased worldwide. It is well established that different child-related factors such as food approach behaviors (i.e. eating behaviors that imply movements towards food) contribute to the development of overweight. However, research is lacking on the underlying mechanisms leading to food approach behaviors, which in turn lead to overweight.

SUBJECT/METHODS

Via parent-report questionnaires, we investigated the relation between the personality trait reward sensitivity and body weight in a convenience sample of 211 children aged 2.5-9 years. We further investigated the intervening role of food approach behaviors in the association between reward sensitivity and body weight.

RESULTS

Unexpectedly, there was no direct association between reward sensitivity and body weight. Despite the absence of a direct effect, a significant indirect association was found between reward sensitivity and body weight through the intervening food approach variables (i.e. food responsive behavior and external eating).

CONCLUSIONS

These results highlight the importance of the focus on eating behaviors as well as trait characteristics in prevention programs for overweight.

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.

Special Article: Physical Activity, Physical Fitness, and Cardiovascular Risk Factors in Childhood

In adults, physical activity and exercise training are associated with reduced cardiovascular morbidity and mortality, a reduced likelihood of developing adverse cardiovascular risk factors, and improved insulin sensitivity. In childhood, participation in appropriate physical activity may prevent the development of cardiovascular risk factors in the future and complement treatment of existing cardiovascular risk factors, including hypertension, dyslipidemia, and overweight. Exercise in children can also significantly improve insulin sensitivity independent of weight loss. These e fects are mediated in overweight children by increases in lean body mass relative to fat mass and associated improvements in inflammatory mediators, endothelial function, and the associated adverse hormonal milieu.

Environmental components of childhood obesity prevention interventions: an overview of systematic reviews

Childhood obesity has a complex multi-factorial aetiology grounded in environmental and individual level factors that affect behaviour and outcomes. An ecological, systems-based approach to addressing childhood obesity is increasingly being advocated. The primary aim of this review is to summarize the evidence reported in systematic reviews on the effectiveness of population-level childhood obesity prevention interventions that have an environmental component. We conducted a systematic review of reviews published since 1995, employing a standardized search strategy in nine databases. Inclusion criteria required that reviews be systematic and evaluated at least one population-level, environmental intervention in any setting aimed at preventing or reducing obesity in children (5-18 years). Sixty-three reviews were included, ten of which were of high quality. Results show modest impact of a broad range of environmental strategies on anthropometric outcomes. Systematic reviews vary in methodological quality, and not all relevant primary studies may be included in each review. To ensure relevance of our findings to practice, we also report on relevant underlying primary studies, providing policy-relevant recommendations based on the evidence reviewed. Greater standardization of review methods and reporting structures will benefit policymakers and public health professionals seeking informed decision-making.

Socioeconomic Factors Influence Physical Activity and Sport in Quebec Schools

BACKGROUND

School environments providing a wide selection of physical activities and sufficient facilities are both essential and formative to ensure young people adopt active lifestyles. We describe the association between school opportunities for physical activity and socioeconomic factors measured by low-income cutoff index, school size (number of students), and neighborhood population density.

METHODS

A cross-sectional survey using a 2-stage stratified sampling method built a representative sample of 143 French-speaking public schools in Quebec, Canada. Self-administered questionnaires collected data describing the physical activities offered and schools' sports facilities. Descriptive and bivariate analyses were performed separately for primary and secondary schools.

RESULTS

In primary schools, school size was positively associated with more intramural and extracurricular activities, more diverse interior facilities, and activities promoting active transportation. Low-income primary schools were more likely to offer a single gym. Low-income secondary schools offered lower diversity of intramural activities and fewer exterior sporting facilities. High-income secondary schools with a large school size provided a greater number of opportunities, larger infrastructures, and a wider selection of physical activities than smaller low-income schools.

CONCLUSIONS

Results reveal an overall positive association between school availability of physical and sport activity and socioeconomic factors.

The Effectiveness of Screening for Obesity in Primary Care: Weighing the Evidence

In response to growing alarm about the increase in the prevalence of obesity in the United States, several organizations have recommended that physicians screen their adult patients for this condition and initiate treatment. Screening can be an effective intervention when the condition is grave and prevalent, when an accurate test exists, when effective treatment exists, when the screening program itself does not pose undue risks, and when early detection and treatment improve outcomes. This article critically reviews the evidence supporting these criteria in the case of obesity in adults. It extends previous reviews by assessing the potential impact that uncertainties in the evidence base may have on the effectiveness a screening program. It also examines the feasibility of such a program. We conclude that following the recommendation to screen all adults for obesity is unlikely to improve outcomes.

Vietnamese mother's conceptions of childhood overweight: findings from a qualitative study

Background

Childhood overweight and obesity is a new and emerging problem in Vietnam. The so far observed prevalence increases have pointed to the need for public health intervention strategies with parents as crucial resources for change.

Objective

The aim of this study was to understand mothers’ conceptions of childhood overweight.

Design

Four focus group discussions were conducted with a total of 33 mothers of preschool children, 4–6 years old, living in urban and rural districts of Hanoi, Vietnam. The discussions were audio taped and transcribed verbatim. The obtained data were analyzed using the principles of phenomenography.

Results

Four main categories with 13 subcategories emerged in the process of analysis. The first category, called ‘Concept of overweight’, contained mothers’ views on childhood overweight. A major concern was the negative aspects of overweight such as impaired social interaction and health problems. The second category, ‘Identification of overweight’, described the ways mothers use to recognize overweight in children: own experience, growth chart, and public or health care system's information. The third category, ‘Causes of overweight’, showed mothers’ understanding of factors possibly contributing to overweight development: unhealthy food and lifestyle, genetic susceptibility, parent's lack of knowledge, and limited time to take care of children as well as economic improvement. The fourth category, ‘Management of overweight’, described the ways mothers use to manage a child's weight problem: control of their food intake, increasing their physical activity, and encouraging their child self-control. However, they find such strategies difficult to implement and their intentions are sometimes challenged by the child's grandparents.

Conclusions

The study gives an understanding of the mothers’ conceptions of four important and practically useful aspects of overweight in children. The findings highlight the roles of media and the health care system in enhancing a social awareness of the problem and the need for prevention. Growth charts need to be used more regularly and consciously in child health care for early detection of children at risk and as a tool for information to parents. When designing intervention programs, the entire extended families, especially grandparents and their roles, need to be considered.

Assessing the usefulness of systematic reviews for policymakers in public health: A case study of overweight and obesity prevention interventions

OBJECTIVE

Systematic reviews (SRs) should include policy-relevant information in order to more readily inform policy and practice. We investigated whether SRs of overweight and obesity prevention interventions are framed in such a way that maximises their usefulness for policymakers.

METHOD

We conducted a systematic review of SRs of overweight and obesity prevention interventions published in 4 databases any time up to December 2014. We analysed the SRs for their usefulness to policymakers, using a coding frame developed based on literature around what policymakers want and need from systematic reviews. Systematic reviews were assessed for a) policy links and framing; b) quality assessment and conflict of interest statements: and c) discussion of policy implications.

RESULTS

Of the 153 SRs that met the inclusion criteria, very few (7%) had authors from policy-based organisations, 48% had funding from such organisations, and almost a third (31%) framed their introduction or aims around policy. Most (69%) discussed issues affecting generalisability of the SR findings but only a quarter (24%) discussed cost or cost-effectiveness of the intervention under investigation. Less than a third (29%) of SRs discussed the policy implications of their findings. SRs that were policy-framed were significantly more likely to discuss costs (PR=1.8, 95%CI 1.0-3.0) and policy implications (PR=2.5, 95%CI 1.5-4.0).

CONCLUSION

SRs should discuss the policy and practice implications of their findings to maximise the influence of SRs on policy making. It is recommended that SR guidelines are updated to include generalisability and discussion of policy and practice implications as a requirement.

Physical activity in overweight and obese adolescents: systematic review of the effects on physical fitness components and cardiovascular risk factors

BACKGROUND

The increasing prevalence of obesity in the pediatric age range has become a major concern. Studies have investigated the role of physical activity (PA) to prevent obesity in this population. However, previous reviews did not focus on the effects of PA in overweight/obese adolescents on physical fitness and risk factors for cardiovascular disease altogether.

OBJECTIVE

The present systematic review analyzed trials investigating the effect of PA on aerobic capacity, muscle strength, body composition, hemodynamic variables, biochemical markers, and endothelial function in obese/overweight adolescents.

METHODS

PubMed, LILACS, Web of Science, Scopus (including Embase), and SPORTDiscus databases were searched for relevant reports without time limits. Inclusion criteria included studies published in English, with overweight and obese adolescents aged 12-17 years. The review was registered (Number CRD42013004632) on PROSPERO, the International Prospective Register of Systematic Reviews.

RESULTS

The results indicated that PA is associated with significant and beneficial changes in fat percentage, waist circumference, systolic blood pressure, insulin, low-density lipoprotein cholesterol, and total cholesterol, as well as with small non-significant changes in diastolic blood pressure, glucose, and high-density lipoprotein cholesterol.

CONCLUSION

Although limited, results from controlled trials suggest that PA intervention may improve physical fitness and risk factors for cardiovascular disease in adolescents who are overweight or obese.

Physical activity and cardiovascular risk factors in children: meta-analysis of randomized clinical trials

OBJECTIVE

To assess the effects of physical activity interventions in preventing cardiovascular risk factors in childhood through a systematic review and meta-analysis of randomized clinical trials (RCTs).

METHODS

A search of online databases (PubMed, EMBASE and Cochrane CENTRAL) was conducted from inception until June 2013. RCTs enrolling children 6-12years old conducted physical activity interventions longer than 6months, assessing their effect on body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP), total cholesterol (TC) and triglycerides (TG) were included. Data analysis was performed using a random-effects model.

RESULTS

Of 23.091 articles retrieved, 11 RCTs (10.748 subjects) were included. Physical activity interventions were not associated with reductions of BMI [-0.03kg/m(2) (95%CI -0.16, 0.13) I(2) 0%]. However, there was an association between the interventions and reduction of SBP [-1.25mmHg (95%CI -2.47, -0.02) I(2) 0%], DBP [-1.34mmHg (95%CI -2.57, -0.11) I(2) 43%] and TG [-0.09mmol/L (95%CI -0.14, -0.04) I(2) 0%], and increase of TC [0.14mmol/L (95%CI 0.01, 0.27) I(2) 0%].

CONCLUSION

As physical activity intervention programs lasting longer than 6months are associated with reductions in blood pressure levels and triglycerides, they should be considered to be included in prevention programs for cardiovascular diseases in schoolchildren.

Effects of exercise on BMI z-score in overweight and obese children and adolescents: a systematic review with meta-analysis

BACKGROUND

Overweight and obesity are major public health problems in children and adolescents. The purpose of this study was to conduct a systematic review with meta-analysis to determine the effects of exercise (aerobic, strength or both) on body mass index (BMI) z-score in overweight and obese children and adolescents.

METHODS

Studies were included if they were randomized controlled exercise intervention trials ≥ 4 weeks in overweight and obese children and adolescents 2 to 18 years of age, published in any language between 1990-2012 and in which data were available for BMI z-score. Studies were retrieved by searching eleven electronic databases, cross-referencing and expert review. Two authors (GAK, KSK) selected and abstracted data. Bias was assessed using the Cochrane Risk of Bias Assessment Instrument. Exercise minus control group changes were calculated from each study and weighted by the inverse of the variance. All results were pooled using a random-effects model with non-overlapping 95% confidence intervals (CI) considered statistically significant. Heterogeneity was assessed using Q and I2 while funnel plots and Egger's regression test were used to assess for small-study effects. Influence and cumulative meta-analysis were performed as well as moderator and meta-regression analyses.

RESULTS

Of the 4,999 citations reviewed, 835 children and adolescents (456 exercise, 379 control) from 10 studies representing 21 groups (11 exercise, 10 control) were included. On average, exercise took place 4 x week for 43 minutes per session over 16 weeks. Overall, a statistically significant reduction equivalent to 3% was found for BMI z-score (Χ¯, -0.06, 95% CI, -0.09 to -0.03; Q = 24.9, p = 0.01; I(2)=59.8%). No small-study effects were observed and results remained statistically significant when each study was deleted from the model once. Based on cumulative meta-analysis, results have been statistically significant since 2009. None of the moderator or meta-regression analyses were statistically significant. The number-needed-to treat was 107 with an estimated 116,822 million obese US children and adolescents and approximately 1 million overweight and obese children and adolescents worldwide potentially improving their BMI z-score by participating in exercise.

CONCLUSIONS

Exercise improves BMI z-score in overweight and obese children and adolescents and should be recommended in this population group. However, a need exists for additional studies on this topic.

A policy-driven multifaceted approach for early childhood physical fitness promotion: impacts on body composition and physical fitness in young Chinese children

BACKGROUND

The prevalence of obesity increased while certain measures of physical fitness deteriorated in preschool children in China over the past decade. This study tested the effectiveness of a multifaceted intervention that integrated childcare center, families, and community to promote healthy growth and physical fitness in preschool Chinese children.

METHODS

This 12-month study was conducted using a quasi-experimental pretest/posttest design with comparison group. The participants were 357 children (mean age = 4.5 year) enrolled in three grade levels in two childcare centers in Beijing, China. The intervention included: 1) childcare center intervention (physical activity policy changes, teacher training, physical education curriculum and food services training), 2) family intervention (parent education, internet website for support, and family events), and 3) community intervention (playground renovation and community health promotion events). The study outcome measures included body composition (percent body fat, fat mass, and muscle mass), Body Mass Index (BMI) and BMI z-score and physical fitness scores in 20-meter agility run (20M-AR), broad jump for distance (BJ), timed 10-jumps, tennis ball throwing (TBT), sit and reach (SR), balance beam walk (BBW), 20-meter crawl (20M-C)), 30-meter sprint (30M-S)) from a norm referenced test. Measures of process evaluation included monitoring of children's physical activity (activity time and intensity) and food preparation records, and fidelity of intervention protocol implementation.

RESULTS

Children in the intervention center significantly lowered their body fat percent (-1.2%, p < 0.0001), fat mass (-0.55 kg, p <0.0001), and body weight (0.36 kg, p <0.02) and increased muscle mass (0.48 kg, p <0.0001), compared to children in the control center. They also improved all measures of physical fitness except timed 10-jumps (20M-AR: -0.74 seconds, p < 0.0001; BJ: 8.09 cm, p < 0.0001; TBT: 0.52 meters, p < 0.006; SR: 0.88 cm, p < 0.03; BBW: -2.02 seconds, p <0.0001; 30M-S: -0.45 seconds, p < 0.02; 20M-C: -3.36 seconds, p < 0.0001). Process evaluation data showed that the intervention protocol was implemented with high fidelity.

CONCLUSIONS

The study demonstrated that a policy-driven multi-faceted intervention can improve preschool children's body composition and physical fitness. Program efficacy should be tested in a randomized trial.

TRIAL REGISTRATION

ChiCTR-ONRC-14004143.

Effect of a school-based active play intervention on sedentary time and physical activity in preschool children

Early childhood is a critical time for promoting physical activity. Few studies have investigated the effect of interventions in this population. The aim of this study was to investigate the effect of a school-based active play intervention on preschool children's sedentary time and physical activity. Preschool children were recruited from randomly selected preschools. Schools were randomly assigned to an intervention or comparison group. One teacher per intervention school received training from active play professionals in the delivery of a 6-week active play programme. Comparison schools continued their usual practice. Children wore a uni-axial accelerometer for 7 days at baseline, immediately after and at 6-month post-intervention. No significant intervention effects were observed for sedentary time or physical activity. However, sex and hours spent at school were significant predictors of physical activity. Children who spent fewer hours (half-day children) at school were significantly more active than their full-day counterparts. Physical activity during the intervention classes was high even though neither daily physical activity nor sedentary time changed. Notably children who spent more time at preschool were less active suggesting that preschool was not as conducive to physical activity engagement as other environments.

Current mHealth technologies for physical activity assessment and promotion

CONTEXT

Novel mobile assessment and intervention capabilities are changing the face of physical activity (PA) research. A comprehensive systematic review of how mobile technology has been used for measuring PA and promoting PA behavior change is needed.

EVIDENCE ACQUISITION

Article collection was conducted using six databases from February to June 2012 with search terms related to mobile technology and PA. Articles that described the use of mobile technologies for PA assessment, sedentary behavior assessment, and/or interventions for PA behavior change were included. Articles were screened for inclusion and study information was extracted.

EVIDENCE SYNTHESIS

Analyses were conducted from June to September 2012. Mobile phone-based journals and questionnaires, short message service (SMS) prompts, and on-body PA sensing systems were the mobile technologies most utilized. Results indicate that mobile journals and questionnaires are effective PA self-report measurement tools. Intervention studies that reported successful promotion of PA behavior change employed SMS communication, mobile journaling, or both SMS and mobile journaling.

CONCLUSIONS

mHealth technologies are increasingly being employed to assess and intervene on PA in clinical, epidemiologic, and intervention research. The wide variations in technologies used and outcomes measured limit comparability across studies, and hamper identification of the most promising technologies. Further, the pace of technologic advancement currently outstrips that of scientific inquiry. New adaptive, sequential research designs that take advantage of ongoing technology development are needed. At the same time, scientific norms must shift to accept "smart," adaptive, iterative, evidence-based assessment and intervention technologies that will, by nature, improve during implementation.

The impact of a 20-month physical activity intervention in child care centers on motor performance and weight in overweight and healthy-weight preschool children

A child-centered physical activity intervention was administered in child care centers over 20 months to promote motor performance and reduce weight in preschool children. The intervention group (N = 211) received at least one weekly 45-min. session of physical education and sessions of physical activities of at least 20 minutes on the other days. Control children (N = 217) experienced the regular curriculum, which consisted of one session of physical activities of 45 min. per week. At the end of the study, children in the intervention group surpassed children in the control group in motor performance (body coordination, physical fitness, and dexterity, measured by a motor test battery MoTB 3-7). Children in the top 20% by BMI at the beginning of the study ("high weight") had inferior motor performance. Children with higher BMIs in the intervention group had better motor scores than children with higher BMIs in the control group, but the intervention had no effect on body weight, BMI, or skinfold thickness.

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

BACKGROUND

The World Health Organization (WHO) estimates that 1.9 million deaths worldwide are attributable to physical inactivity and at least 2.6 million deaths are a result of being overweight or obese. In addition, WHO estimates that physical inactivity causes 10% to 16% of cases each of breast cancer, colon, and rectal cancers as well as type 2 diabetes, and 22% of coronary heart disease and the burden of these and other chronic diseases has rapidly increased in recent decades.

OBJECTIVES

The purpose of this systematic review was to summarize the evidence of the effectiveness of school-based interventions in promoting physical activity and fitness in children and adolescents.

SEARCH METHODS

The search strategy included searching several databases to October 2011. In addition, reference lists of included articles and background papers were reviewed for potentially relevant studies, as well as references from relevant Cochrane reviews. Primary authors of included studies were contacted as needed for additional information.

SELECTION CRITERIA

To be included, the intervention had to be relevant to public health practice (focused on health promotion activities), not conducted by physicians, implemented, facilitated, or promoted by staff in local public health units, implemented in a school setting and aimed at increasing physical activity, included all school-attending children, and be implemented for a minimum of 12 weeks. In addition, the review was limited to randomized controlled trials and those that reported on outcomes for children and adolescents (aged 6 to 18 years). Primary outcomes included: rates of moderate to vigorous physical activity during the school day, time engaged in moderate to vigorous physical activity during the school day, and time spent watching television. Secondary outcomes related to physical health status measures including: systolic and diastolic blood pressure, blood cholesterol, body mass index (BMI), maximal oxygen uptake (VO2max), and pulse rate.

DATA COLLECTION AND ANALYSIS

Standardized tools were used by two independent reviewers to assess each study for relevance and for data extraction. In addition, each study was assessed for risk of bias as specified in the Cochrane Handbook for Systematic Reviews of Interventions. Where discrepancies existed, discussion occurred until consensus was reached. The results were summarized narratively due to wide variations in the populations, interventions evaluated, and outcomes measured.

MAIN RESULTS

In the original review, 13,841 records were identified and screened, 302 studies were assessed for eligibility, and 26 studies were included in the review. There was some evidence that school-based physical activity interventions had a positive impact on four of the nine outcome measures. Specifically positive effects were observed for duration of physical activity, television viewing, VO2 max, and blood cholesterol. Generally, school-based interventions had little effect on physical activity rates, systolic and diastolic blood pressure, BMI, and pulse rate. At a minimum, a combination of printed educational materials and changes to the school curriculum that promote physical activity resulted in positive effects.In this update, given the addition of three new inclusion criteria (randomized design, all school-attending children invited to participate, minimum 12-week intervention) 12 of the original 26 studies were excluded. In addition, studies published between July 2007 and October 2011 evaluating the effectiveness of school-based physical interventions were identified and if relevant included. In total an additional 2378 titles were screened of which 285 unique studies were deemed potentially relevant. Of those 30 met all relevance criteria and have been included in this update. This update includes 44 studies and represents complete data for 36,593 study participants. Duration of interventions ranged from 12 weeks to six years.Generally, the majority of studies included in this update, despite being randomized controlled trials, are, at a minimum, at moderate risk of bias. The results therefore must be interpreted with caution. Few changes in outcomes were observed in this update with the exception of blood cholesterol and physical activity rates. For example blood cholesterol was no longer positively impacted upon by school-based physical activity interventions. However, there was some evidence to suggest that school-based physical activity interventions led to an improvement in the proportion of children who engaged in moderate to vigorous physical activity during school hours (odds ratio (OR) 2.74, 95% confidence interval (CI), 2.01 to 3.75). Improvements in physical activity rates were not observed in the original review. Children and adolescents exposed to the intervention also spent more time engaged in moderate to vigorous physical activity (with results across studies ranging from five to 45 min more), spent less time watching television (results range from five to 60 min less per day), and had improved VO2max (results across studies ranged from 1.6 to 3.7 mL/kg per min). However, the overall conclusions of this update do not differ significantly from those reported in the original review.

AUTHORS' CONCLUSIONS

The evidence suggests the ongoing implementation of school-based physical activity interventions at this time, given the positive effects on behavior and one physical health status measure. However, given these studies are at a minimum of moderate risk of bias, and the magnitude of effect is generally small, these results should be interpreted cautiously. Additional research on the long-term impact of these interventions is needed.

Physical activity promotion and obesity prevention in Girl Scouts: Scouting Nutrition and Activity Program+

BACKGROUND

A previous version of Scouting Nutrition and Activity Program (SNAP) resulted in greater physical activity (PA) during troop meetings, but no impact on girls' body mass index (BMI) or overall PA. The purpose of this study was to evaluate the effects of a 6-month intervention that coupled the evidence-based program SNAP with a channel of communication to parents using health report cards.

METHODS

Thirty-two Girl Scouts (mean age = 9.5, SD = 1.4 years) received the SNAP+ intervention. Girls were measured before and after the intervention on body composition, BMI, and 7-day step counts. Troop leaders were trained to implement an interactive obesity-prevention curriculum. Parents received health report cards designed to provide personalized information about their daughters' PA and weight status.

RESULTS

The full sample of participants took more steps per day after the intervention (mean difference = 1741, P= 0.007). Results showed that lower values for body fat percentage (P= 0.620), BMI percentile (P= 0.100) and BMI z-scores (P= 0.055) at intervention end were not statistically significant. In the subsample of girls at risk for overweight and obesity, there were lower values for BMI z-score (P= 0.010), BMI percentile (P= 0.027), and body fat percentage (P= 0.053).

CONCLUSIONS

From this preliminary study, the SNAP+ intervention appears to be effective for Scout-based promotion of PA, and for the prevention of overweight and obesity in at-risk Girl Scouts, but further evaluation through a fully powered randomized controlled trial is warranted.

An Objective Method for Measurement of Sedentary Behavior in 3- to 4-Year Olds

OBJECTIVE

To test the ability of accelerometry to quantify sedentary behavior in 3- to 4-year-old children.

RESEARCH METHODS AND PROCEDURES

We developed a cut-off for accelerometry output (validation study) in 30 healthy 3 to 4 year olds, which provided highest sensitivity and specificity for the detection of sedentary behavior relative to a criterion method of measurement, direct observation using the children's physical activity form. We then cross-validated the cut-off in an independent sample of healthy 3 to 4 year olds (n = 52).

RESULTS

In the validation study, optimal sensitivity and specificity for the detection of sedentary behavior were obtained at an accelerometry output cut-off of <1100 counts/min. In the cross-validation, sensitivity was 83%: 438/528 inactive minutes were correctly classified. Specificity was 82%: 1251/1526 noninactive minutes were correctly classified using this cut-off.

DISCUSSION

Sedentary behavior can be quantified objectively in young children using accelerometry. This new technique could be considered for a wide variety of applications in the etiology, prevention, and treatment of childhood obesity.

Translating the PLAYgrounds program into practice: a process evaluation using the RE-AIM framework

OBJECTIVES

To present the results of the process evaluation of the PLAYgrounds program, using the RE-AIM framework.

DESIGN

This study provides information regarding Reach, Adoption, Implementation and Maintenance.

METHODS

The PLAYgrounds program promotes increasing levels of physical activity in 6-12 years old children and was evaluated using the RE-AIM framework in 4 intervention schools. Data collection consisted of a physical activity questionnaire with children (n=765, Reach), SOPLAY observations (Implementation and Maintenance), questionnaires on the satisfaction of the implemented elements with teachers (n=59) and children (n=730, Implementation) and interviews for increased depth of information. In addition a simple counting of participating schools, describing of non-participating reasons and characteristics of the schools were documented (Adoption).

RESULTS

Reach of the target population (i.e. inactive children) was 60.7% (n=464) and the target population was representative for populations in low-SES neighbourhoods. The PLAYgrounds program was adopted by 4 schools (80%), at which 5 (from 7) program elements were successfully implemented. At 18 months follow-up, 3 of those 5 elements were completely maintained.

CONCLUSIONS

Adoption, Implementation, and Maintenance proved to be very high. Most likely due to the PLAYgrounds program being a complete intervention package that included financial, material, and staff support. Therefore, it is recommended to retain this high level of support when introducing the PLAYgrounds (or any other intervention) program in schools. In the future it would be recommended to evaluate the PLAYgrounds program on maintenance in schools where the key-person is employed at the school and funding is not available.

Adolescents' Views on Active and Non-Active Videogames: A Focus Group Study

OBJECTIVE

Active games require whole-body movement and may be an innovative tool to substitute sedentary pastime with more active time and may therefore contribute to adolescents' health. To inform strategies aimed at reducing sedentary behavior by replacing non-active with active gaming, perceptions and context of active and non-active gaming are explored.

SUBJECTS AND METHODS

Six focus groups were conducted with adolescents 12-16 years old representing a range of education levels. A semistructured question route was used containing questions about perceptions and the context of gaming.

RESULTS

The adolescents had positive attitudes toward active gaming, especially the social interactive aspect, which was greatly appreciated. A substantial number of adolescents enjoyed non-active games more than active ones, mainly because of better game controls and more diversity in non-active games. Active games were primarily played when there was a social gathering. Few game-related rules and restrictions at home were reported.

CONCLUSIONS

Given the positive attitudes of adolescents and the limited restrictions for gaming at home, active videogames may potentially be used in a home setting as a tool to reduce sedentary behavior. However, to make active games as appealing as non-active games, attention should be paid to the quality, diversity, and sustainability of active games, as these aspects are currently inferior to those of traditional non-active games.

Recent advances in obesity: genetics and beyond

The prevalence of obesity, which is a heritable trait that arises from the interactions of multiple genes and lifestyle factors, continues to increase worldwide, causing serious health problems and imposing a substantial economic burden on societies. For the past several years, various genetic epidemiological approaches have been utilized to identify genetic loci for obesity. Recent evidence suggests that development of obesity involves hormones and neurotransmitters (such as leptin, cocaine- and amphetamine-regulated transcript (CART), and ghrelin) that regulate appetite and energy expenditure. These hormones act on specific centers in the brain that regulate the sensations of satiety. Mutations in these hormones or their receptors can lead to obesity. Aberrant circadian rhythms and biochemical pathways in peripheral organs or tissues have also been implicated in the pathology of obesity. More interestingly, increasing evidence indicates a potential relation between obesity and central nervous system disorders (such as cognitive deficits). This paper discusses recent advances in the field of genetics of obesity with an emphasis on several established loci that influence obesity. These recently identified loci may hold the promise to substantially improve our insights into the pathophysiology of obesity and open up new therapeutic strategies to combat growing obesity epidemic facing the human population today.

An adaptive community-based participatory approach to formative assessment with high schools for obesity intervention*

BACKGROUND

In the emerging debate around obesity intervention in schools, recent calls have been made for researchers to include local community opinions in the design of interventions. Community-based participatory research (CBPR) is an effective approach for forming community partnerships and integrating local opinions. We used CBPR principles to conduct formative research in identifying acceptable and potentially sustainable obesity intervention strategies in 8 New Mexico school communities.

METHODS

We collected formative data from 8 high schools on areas of community interest for school health improvement through collaboration with local School Health Advisory Councils (SHACs) and interviews with students and parents. A survey based on formative results was created to assess acceptability of specific intervention strategies and was provided to SHACs. Quantitative data were analyzed using descriptive statistics while qualitative data were evaluated using an iterative analytic process for thematic identification.

RESULTS

Key themes identified through the formative process included lack of healthy food options, infrequent curricular/extracurricular physical activity opportunities, and inadequate exposure to health/nutritional information. Key strategies identified as most acceptable by SHAC members included healthier food options and preparation, a healthy foods marketing campaign, yearly taste tests, an after-school noncompetitive physical activity program, and community linkages to physical activity opportunities.

CONCLUSION

An adaptive CBPR approach for formative assessment can be used to identify obesity intervention strategies that address community school health concerns. Eight high school SHACs identified 6 school-based strategies to address parental and student concerns related to obesity.

Critical narrative review to identify educational strategies promoting physical activity in preschool

The aim of this narrative review is critically to evaluate educational strategies promoting physical activity that are used in the preschool setting in the context of obesity prevention programmes. Literature search was conducted between April and August 2010 in English and German databases (PubMED, PsychINFO, PSYNDEX, ERIC, FIS Bildung). Outcomes considered were time and intensity of physical activity, motor skills or measures of body composition. A total of 19 studies were included. Ten studies added physical activity lessons into their curriculum, one study provided more time for free play, eight studies focused on the social and play environment. Studies reporting positive outcomes implemented physical activity sessions that lasted at least 30 min d(-1). Several studies showed that children are most active in the first 10-15 min. The existence or installation of playground markings or fixed play equipment had no effect, whereas the presence or addition of portable play equipment was positively correlated with moderate-to-vigorous physical activity. Teacher training may be a key element for successful interventions. To overcome time constraints, a suggested solution is to integrate physical activity into daily routines and other areas of the preschool curriculum.

Healthy Beginnings Trial Phase 2 study: follow-up and cost-effectiveness analysis

BACKGROUND

In 2007, we commenced the Healthy Beginnings Trial (HBT) Phase 1 study, which is the first randomised controlled trial (RCT) to test the effectiveness of an early childhood obesity intervention in children aged up to 2 years. The results were promising with significant improvements in infant feeding practices and a lower mean body mass index (BMI). The aims of this proposed Phase 2 study are to determine if the early intervention will lead to a lower mean BMI, lower screen time, improved dietary behaviours and demonstrated cost-effectiveness of the intervention, in children aged 3½ and 5 years.

METHODS/DESIGN

In Phase 1 of HBT 667 families participated in the RCT. No further intervention will be carried out in HBT Phase 2. In this study the intervention and control groups will be compared for children's outcomes at ages 3½ and 5 years. Primary outcome measures will be 1) BMI, 2) selected dietary measures using a validated survey tool, and 3) physical activity and screen time using a new generation of tri-axial accelerometers. Intention to treat principles will be used in the analysis. Multiple imputation will be used to impute outcomes for subjects lost to follow-up. A cost-effectiveness analysis (CEA) and cost-utility analysis for both HBT Phase 1 and 2 will also be conducted.

DISCUSSION

This is the first time that a home-based early intervention strategy has been implemented to prevent the development of childhood obesity and obesity-conducive behaviours. The results of this trial will ascertain whether early intervention during the first 2 years of life is effective and cost-effective in preventing childhood overweight and obesity at 3½ and 5 years old.

Changing the future of obesity: science, policy, and action

The global obesity epidemic has been escalating for four decades, yet sustained prevention efforts have barely begun. An emerging science that uses quantitative models has provided key insights into the dynamics of this epidemic, and enabled researchers to combine evidence and to calculate the effect of behaviours, interventions, and policies at several levels--from individual to population. Forecasts suggest that high rates of obesity will affect future population health and economics. Energy gap models have quantified the association of changes in energy intake and expenditure with weight change, and have documented the effect of higher intake on obesity prevalence. Empirical evidence that shows interventions are effective is limited but expanding. We identify several cost-effective policies that governments should prioritise for implementation. Systems science provides a framework for organising the complexity of forces driving the obesity epidemic and has important implications for policy makers. Many parties (such as governments, international organisations, the private sector, and civil society) need to contribute complementary actions in a coordinated approach. Priority actions include policies to improve the food and built environments, cross-cutting actions (such as leadership, healthy public policies, and monitoring), and much greater funding for prevention programmes. Increased investment in population obesity monitoring would improve the accuracy of forecasts and evaluations. The integration of actions within existing systems into both health and non-health sectors (trade, agriculture, transport, urban planning, and development) can greatly increase the influence and sustainability of policies. We call for a sustained worldwide effort to monitor, prevent, and control obesity.

Interventions for the prevention of overweight and obesity in preschool children: a systematic review of randomized controlled trials

The objective of this study was to analyse interventions for the prevention of overweight and obesity in children under 5 years of age. We carried out a systematic review focusing exclusively on randomized controlled trials (RCTs). Data sources include Medline, Cochrane Library, EMBASE, CINHAL, PsychInfo and Web of Science. Data were extracted from seventeen articles describing seven RCTs identified through electronic search, screening of references in systematic reviews, own files and contact with authors. RCTs were assessed with the Jadad scale. Four trials were carried out in preschool settings, one with an exclusive educational component, two with an exclusive physical activity component and one with both. Two trials were family-based, with education and counselling for parents and children. The remaining trial was carried out in maternity hospitals, with a training intervention on breastfeeding. None of the interventions had an effect in preventing overweight and obesity. The failure to show an effect may be due to the choice of outcomes, the quality of the RCTs, the suboptimal implementation of the interventions, the lack of focus on social and environmental determinants. More rigorous research is needed on interventions and on social and environmental factors that could impact on lifestyle.

Systematic review of the effectiveness of weight management schemes for the under fives

Overweight and obesity in pre-school children are an increasing problem, with poor diet and exercise habits laying the foundation for serious health risks in later life. Yet most research into childhood obesity has focused on school-age children. Two previous systematic reviews of pre-school children have included uncontrolled designs and self-report outcomes potentially biasing the results in favour of the interventions. We have conducted a systematic review of the effectiveness and cost-effectiveness of weight management schemes for the under fives restricting the inclusion criteria to controlled trials with objective measures. We found four effectiveness randomized controlled trials of prevention. No treatment or cost-effectiveness studies were found. Only one study in a Latino community showed a statistically significant advantage from the intervention in a slower rate of increase in body mass index. However, trends in decrease in body mass index and weight loss favoured the intervention groups in other studies. From the studies characteristics we hypothesize that important features to include in future interventions may be; cultural sensitivity, sustained moderate to vigorous exercise, active engagement of the parents in the programme and as role models of healthy living and active engagement of the children in nutrition education. Further randomized controlled trials are needed in this population.

Translating research to practice: using the RE-AIM framework to examine an evidence-based physical activity intervention in primary school settings

Although there has been an increase in the availability of effective, evidence-based physical activity interventions in school settings during the past decade, there is a paucity of published research focusing on the translation of these effective interventions into real-world practice. The purpose of this research was to examine the translatability of an existing school-based physical activity intervention. More specifically, this research sought to identify the barriers and facilitators in adopting, implementing, and maintaining a school-based physical activity intervention using RE-AIM as a theoretical evaluation framework. It was concluded that interventions that consider issues around complexity and compatibility with the school setting are more likely to be adopted, implemented, and maintained. It was recommended that future evaluations of physical activity interventions should not be limited to testing internal validity, but should consider external validity and ecological aspects, relevant to increasing dissemination in real-world settings.

Patterns of moderate and vigorous physical activity in obese and overweight compared with non-overweight children

OBJECTIVE

We determined whether overweight and obese children performed less combined moderate and vigorous physical activity (MVPA), less vigorous physical activity (VPA) alone, and had distinct patterns of sustained MVPA or VPA compared with non-overweight children.

METHODS

We monitored 106 children (aged 8 to 10 years) for 7 consecutive days using accelerometers. Differences in mean daily MVPA and VPA were assessed by comparing non-overweight (NOW) with overweight and obese (OW/OB) participants using descriptive statistics and regression analysis. We used an algorithm to identify periods of consecutive minutes where MVPA or VPA was continuous, called bouts. We then compared the bouts performed by NOW versus OW and OB participants with respect to the mean of the counts·minute(-1) for the minutes included in the bout, their mean length in minutes, and the number of MVPA bouts performed in sequence.

RESULTS

The non-overweight group averaged 143 minutes of MVPA per day versus 120 minutes among the OW/OB (p=0.004). The OW/OB group had fewer MVPA bouts per day compared with the NOW (11.6 versus17.6, p=0.012). Fewer VPA bouts were associated with greater body mass index z-score (p<0.001). The NOW children had more intense body motion during MVPA bouts and performed a greater proportion of MVPA bouts in sequences of five or more consecutive bouts, compared with the OW/OB (p=0.05 and p=0.002, respectively).

CONCLUSIONS

In addition to performing less physical activity, we found that obese and overweight children had distinct patterns of MVPA and VPA bouts compared with non-overweight peers.

Association Between Short Sleep Duration and Obesity Among South Korean Adolescents

Short sleep duration and obesity are common health concerns in youth. This study of South Korean adolescents explores the association between the two conditions analyzing secondary data from the 2007 Korea Youth Risk Behavior Web-Based Survey. The sample is representative of the South Korean adolescent population ( N = 73,836). For data analysis, analysis of variance, chi-square test, and logistic regression were used. Findings indicated that (a) sleep duration is inversely associated with levels of body mass index, F(4, 72654) = 240.07, p < .0001, and risks for overweight and obesity, χ2(4, 72659) = 27.41, p < .0001; and (b) after controlling for obesity-related factors, reduced sleep is strongly associated with a greater risk for overweight and obesity, OR = 0.94, p < .0001. Given the important link between sleep and obesity, health professionals should consider sleep habits as a significant factor in obesity-related problems of youth.

The impact of child and adolescent obesity treatment interventions on physical activity: a systematic review

Efforts to treat obesity in childhood and adolescence would benefit from a greater understanding of evidence-based strategies to modify physical activity behaviour. A systematic review was conducted to examine the impact of child and adolescent obesity treatment interventions on physical activity. Studies included were randomized controlled trials or controlled trials, with overweight and obese youth (aged < 18 years), which reported statistical analysis of free-living physical activity at pretreatment and post-treatment. Two independent reviewers assessed each study for methodological quality. Seventeen child and three adolescent studies were retrieved, half of which were conducted in the USA. Studies were characterized by small samples of limited cultural and economic diversity. Fifteen studies reported an increase in at least one physical activity outcome at post-test or follow-up. Overall, study quality was rated as low (child median score = 3/10, range = 0-9; adolescent median score = 3/10, range = 2-5) with three child studies classified as high quality (>or=6/10). Research evaluating the effect of child and adolescent obesity treatment trials on physical activity is limited in both quantity and quality. Studies testing innovative, theoretically driven treatment approaches that use robust methodologies are required to better understand generalizable approaches for promoting physical activity participation among obese youth.

Interventions for increasing physical activity at child care

Experts agree that physical activity is critical to children's health and development. Child care is an ideal setting that could be used to increase physical activity given the large number of young children enrolled. To effectively address physical activity at child care, it is necessary to understand what strategies are most effective. This article reviews existing intervention studies targeting physical activity conducted within a child care setting (including preschools, nursery schools, and day care). Given the limited work in this setting, liberal criteria were used that allowed for inclusion of studies with diverse outcomes (physical activity, physical activity-related, motor skills) and a variety of research designs (randomized control, quasi-experimental, single group). Searching six databases, 1355 studies were located, and 19 met inclusion criteria. Half of the studies that assessed intervention impact on physical activity reported significant findings. All five studies measuring motor skills and eight assessing physical activity-related outcomes demonstrated generally positive findings. Although the variety of outcome measures and research quality made it difficult to draw conclusions, findings do provide encouragement that regularly provided, structured physical activity programs can increase the amount and intensity of physical activity that children receive and improve children's motor skills. These studies also demonstrate that the organized child care setting provides multiple targets for intervention beyond structured activity programs; however, additional studies are needed to explore such opportunities.

A meta-analysis of obesity interventions among U.S. minority children

PURPOSE

To quantitatively evaluate the efficacy of interventions designed to prevent or treat obesity among U.S. minority children using meta-analytic techniques.

METHODS

A total of 40 intervention trials involving 10,725 children aged 6-19 years were examined.

RESULTS

Interventions with more components showed a higher mean effect size than those with fewer components: among 32 controlled trials, d = .07 for one-component (n = 6); d = .08 for two-component (n = 15); d = .33 for three-component (n = 10); and d = .71 for four-component (n = 1) interventions. Interventions with parental involvement (n = 22, d = .21) and lifestyle interventions (n = 14, d = .34) showed a greater mean effect size than those without parental involvement (n = 10, d = .05) or lifestyle interventions (n = 18, d = .04), despite the fact that their 90% confidence intervals overlapped. Among uncontrolled trials (n = 8), two-component interventions (n = 5) yielded d = .86 and three-component interventions (n = 3) yielded d = .96.

CONCLUSIONS

Evidence indicates that, among U.S. minority children, obesity interventions with three or more components might be more efficacious than those using fewer components. Parental involvement, lifestyle change, culturally-based adaptation, and interactive computer programs seem to show promise in the reduction of obese minority children.

How useful are systematic reviews of child obesity interventions?

To facilitate the translation of research evidence into practice, policy makers and practitioners require practice-relevant information such as the effectiveness of interventions delivered in specific settings, by various personnel, using various intervention modalities, and descriptions of intervention costs or adverse outcomes. The aim of this study was to review the relevance of information reported in systematic reviews of child obesity interventions in terms of these requirements. A systematic search was conducted for systematic reviews of child obesity interventions published in English between 1990 and 2008. A total of 3150 citations were examined. Of the 44 eligible reviews, 16 examined prevention interventions, 18 examined treatment interventions, and 10 examined both prevention and treatment interventions. Less than 50% of prevention and treatment reviews reported the effect of interventions conducted in specific settings, the effect of interventions conducted by various personnel and the effect of those delivered via various intervention modalities. Similarly, few (4-15%) reviews reported cost or adverse event outcomes. Existing systematic reviews of childhood obesity interventions provide limited practice-relevant information. The potential for benefit from the translation of evidence into practice is therefore limited. Involving end users in systematic review development may improve the relevance of outcomes reported in systematic reviews.