Efeito do exercício físico sobre peso corporal em crianças com excesso de peso: ensaio clínico comunitário randomizado em uma favela no Brasil

Effects of physical activity on body mass and composition of school-age children and adolescents with overweight or obesity: Systematic review focusing on intervention characteristics

OBJECTIVE

The characteristics of physical activity (PA) interventions to improve body mass and composition in pediatric populations are unclear. This systematic review summarized the effects of PA on those outcomes in school-age children and adolescents with overweight or obesity, focusing on training components (frequency, intensity, duration, and type - FITT).

METHODS

Databases were searched for controlled trials applying exclusive PA and including children (5-12 y) or adolescents (13-17 y) with overweight/obesity.

RESULTS

Twenty-seven trials yielding 34 interventions were included. PA was recreational (children: k = 9, n = 478), systematized (children: k = 18, n = 565); or combined (children: k = 7, n = 205). Successful interventions were performed for 6- to 35 weeks (mostly 12-14 weeks), 2- to 5 d/wk (mostly 3 d/wk), during 8- to 60 min (mainly 60 min) with moderate to high intensity (60-90% maximal heart rate or 40-70% heart rate reserve). Half of the interventions applying recreational (4 out of 8), 59% of systematized (10 out of 17), and 57% of combined (4 out of 7) interventions reported improvements in body mass or composition, especially body fat. Benefits were more often reported for body composition (18 out of 34 interventions) than body mass (8 out of 34 interventions), irrespective of the age group.

CONCLUSION

Recreational and systematized PA may improve body mass, and particularly body composition in school-age children and adolescents with overweight or obesity. Successful programs were performed for at least six weeks and applied a PA amount consistent with the minimum recommended for pediatric populations (≥60 min of moderate-to-vigorous PA at least 3 d/wk).

Inter-individual differences in body mass index were not observed as a result of aerobic exercise in children and adolescents with overweight and obesity

BACKGROUND

Exercise has been recommended as an important intervention for reducing adiposity in children and adolescents with overweight and obesity.

OBJECTIVE

Determine whether inter-individual differences exist in relation to exercise-induced changes in adiposity among children and adolescents with overweight and obesity.

METHODS

Meta-analysis of randomized controlled aerobic exercise trials and body mass index (BMI) in kg · m^-2 . Change outcome standard deviations were pooled using the inverse-variance heterogeneity model.

RESULTS

Twenty-eight studies (1185 participants) were included. Inter-individual differences in BMI were -0.1 (95% compatibility interval, -0.7 to 0.7). The 95% prediction interval for inter-individual responses in a future study was -2.9 to 2.9. The probability of a clinically meaningful difference in variability was 29% (possibly clinically important) in favour of controls vs exercisers.

CONCLUSIONS

Inter-individual differences for BMI in kg · m^-2 were not observed as a result of aerobic exercise in children and adolescents with overweight and obesity.

The Effects of Physical Activity and Diet Interventions on Body Mass Index in Latin American Children and Adolescents: A Systematic Review and Meta-Analysis

The objective of this systematic review and meta-analysis is to compare the effect of physical activity only with that of physical activity plus diet interventions on body mass index (BMI) in Latin American children and adolescents. We searched the Medline, Embase, Scopus, Web of Science, and Scielo databases from their inception until March 2020, including studies examining the effect of physical activity or physical activity plus diet interventions on BMI in children and adolescents and based on data from intervention studies. The DerSimonian and Laird method was used to compute a pooled standardized mean difference for BMI in terms of effect size (ES) and respective 95% confidence intervals (CIs). Eighteen studies were included. Analyses were performed based on intervention (four studies were included for physical activity only and four studies were included for physical activity plus diet). In the analysis of physical activity only versus control, there was no effect on BMI (ES = 0.00; 95% CI −0.17–0.17, I² = 0.0%; p = 0.443). In the analysis of physical activity plus diet versus control, there was a decrease in BMI in favour of the intervention group (ES = −0.28; 95% CI −0.42–−0.14, I² = 74.5%; p = 0.001). When ES was estimated considering only the effect in intervention groups, there was no evidence of a decrease in BMI (ES = −0.17; 95% CI −0.44–0.11, I² = 84.5%; p < 0.001) for physical activity only (eight studies). However, there was a statistically significant decrease in BMI (ES = −0.30; 95% CI −0.50–0.11, I² = 95.8%; p < 0.001) for physical activity plus diet (ten studies). Some limitations of this review could compromise our results, but the main limitation that should be stated is the quality of the studies (mainly medium/moderate), especially as physical activity and diet interventions cannot be blinded, compromising the quality of these studies. In summary, this meta-analysis offers evidence that physical activity plus diet interventions produced a reduction in BMI in Latin American children and adolescents, but physical activity only interventions did not.

Exercise and adiposity in overweight and obese children and adolescents: a systematic review with network meta-analysis of randomised trials

OBJECTIVES

Determine both the effects and hierarchy of effectiveness for exercise interventions (aerobic, strength training or both) on selected measures of adiposity (body mass index (BMI) in kg/m², fat mass and per cent body fat) in overweight and obese children and adolescents.

DESIGN

Network meta-analysis of randomised exercise intervention trials.

SETTING

Any setting where a randomised trial could be conducted.

PARTICIPANTS

Overweight and obese male and/or female children and adolescents 2-18 years of age.

INTERVENTIONS

Randomised exercise intervention trials>4 weeks, published between 1 January 1973 and 22 August 2018, and which included direct and/or indirect evidence for aerobic, strength training or combined aerobic and strength training.

PRIMARY OUTCOMES

Changes in BMI in kg/m², fat mass and per cent body fat.

RESULTS

Fifty-seven studies representing 127 groups (73 exercise, 54 control) and 2792 participants (1667 exercise, 1125 control) met the criteria for inclusion. Length of training ([Formula: see text] ± SD) averaged 14.1±6.2 weeks, frequency, 3.3±1.1 days per week and duration 42.0±21.0 min per session. Significant and clinically important reductions in BMI, fat mass and per cent body fat were observed in aerobic versus control comparisons (BMI, mean, 95% CI -1.0, 1.4 to -0.6; fat mass -2.1, -3.3 to -1.0 kg; per cent fat -1.5, -2.2 to -0.9%) and combined aerobic and strength versus control comparisons (BMI -0.7, -1.4 to -0.1; fat mass -2.5, -4.1 to -1.0 kg; per cent fat, -2.2, -3.2 to -1.2%). A significant reduction in per cent fat was also found for strength vs control comparisons (-1.3,-2.5 to -0.1%). Combined aerobic and strength training was ranked first for improving both fat mass (kg) and per cent body fat while aerobic exercise was ranked first for improving BMI.

CONCLUSIONS

Aerobic and combined aerobic and strength training are associated with improvements in adiposity outcomes in overweight and obese children and adolescents.

PROSPERO REGISTRATION NUMBER

CRD42017073103.

Interventions for preventing obesity in children

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.

Exercise and adiposity in overweight and obese children and adolescents: protocol for a systematic review and network meta-analysis of randomised trials

INTRODUCTION

Overweight and obesity is a worldwide public health problem among children and adolescents. However, the magnitude of effect, as well as hierarchy of exercise interventions (aerobic, strength training or both), on selected measures of adiposity is not well established despite numerous trials on this issue. The primary purposes of this study are to use the network meta-analytical approach to determine the effects and hierarchy of exercise interventions on selected measures of adiposity in overweight and obese children and adolescents.

METHODS AND ANALYSIS

Randomised exercise intervention trials >4 weeks, available in any language up to 31 August 2017 and which include direct and/or indirect evidence, will be included. Studies will be located by searching seven electronic databases, cross-referencing and expert review. Dual selection and abstraction of data will occur. The primary outcomes will be changes in body mass index (in kg/m²), fat mass and percent body fat. Risk of bias will be assessed using the Cochrane Risk of Bias assessment instrument while confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation instrument for network meta-analysis. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of exercise treatments (aerobic, strength or both).

ETHICS AND DISSEMINATION

This study does not require ethics approval. Findings will be presented at a professional conference and published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD 42017073103 .

Diet, physical activity and behavioural interventions for the treatment of overweight or obese children from the age of 6 to 11 years

BACKGROUND

Child and adolescent overweight and obesity has increased globally, and can be associated with significant short- and long-term health consequences. This is an update of a Cochrane review published first in 2003, and updated previously in 2009. However, the update has now been split into six reviews addressing different childhood obesity treatments at different ages.

OBJECTIVES

To assess the effects of diet, physical activity and behavioural interventions (behaviour-changing interventions) for the treatment of overweight or obese children aged 6 to 11 years.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS as well as trial registers ClinicalTrials.gov and ICTRP Search Portal. We checked references of studies and systematic reviews. We did not apply any language restrictions. The date of the last search was July 2016 for all databases.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) of diet, physical activity, and behavioural interventions (behaviour-changing interventions) for treating overweight or obese children aged 6 to 11 years, with a minimum of six months' follow-up. We excluded interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or included participants with a secondary or syndromic cause of obesity.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened references, extracted data, assessed risk of bias, and evaluated the quality of the evidence using the GRADE instrument. We contacted study authors for additional information. We carried out meta-analyses according to the statistical guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We included 70 RCTs with a total of 8461 participants randomised to either the intervention or control groups. The number of participants per trial ranged from 16 to 686. Fifty-five trials compared a behaviour-changing intervention with no treatment/usual care control and 15 evaluated the effectiveness of adding an additional component to a behaviour-changing intervention. Sixty-four trials were parallel RCTs, and four were cluster RCTs. Sixty-four trials were multicomponent, two were diet only and four were physical activity only interventions. Ten trials had more than two arms. The overall quality of the evidence was low or very low and 62 trials had a high risk of bias for at least one criterion. Total duration of trials ranged from six months to three years. The median age of participants was 10 years old and the median BMI z score was 2.2.Primary analyses demonstrated that behaviour-changing interventions compared to no treatment/usual care control at longest follow-up reduced BMI, BMI z score and weight. Mean difference (MD) in BMI was -0.53 kg/m2 (95% confidence interval (CI) -0.82 to -0.24); P < 0.00001; 24 trials; 2785 participants; low-quality evidence. MD in BMI z score was -0.06 units (95% CI -0.10 to -0.02); P = 0.001; 37 trials; 4019 participants; low-quality evidence and MD in weight was -1.45 kg (95% CI -1.88 to -1.02); P < 0.00001; 17 trials; 1774 participants; low-quality evidence.Thirty-one trials reported on serious adverse events, with 29 trials reporting zero occurrences RR 0.57 (95% CI 0.17 to 1.93); P = 0.37; 4/2105 participants in the behaviour-changing intervention groups compared with 7/1991 participants in the comparator groups). Few trials reported health-related quality of life or behaviour change outcomes, and none of the analyses demonstrated a substantial difference in these outcomes between intervention and control. In two trials reporting on minutes per day of TV viewing, a small reduction of 6.6 minutes per day (95% CI -12.88 to -0.31), P = 0.04; 2 trials; 55 participants) was found in favour of the intervention. No trials reported on all-cause mortality, morbidity or socioeconomic effects, and few trials reported on participant views; none of which could be meta-analysed.As the meta-analyses revealed substantial heterogeneity, we conducted subgroup analyses to examine the impact of type of comparator, type of intervention, risk of attrition bias, setting, duration of post-intervention follow-up period, parental involvement and baseline BMI z score. No subgroup effects were shown for any of the subgroups on any of the outcomes. Some data indicated that a reduction in BMI immediately post-intervention was no longer evident at follow-up at less than six months, which has to be investigated in further trials.

AUTHORS' CONCLUSIONS

Multi-component behaviour-changing interventions that incorporate diet, physical activity and behaviour change may be beneficial in achieving small, short-term reductions in BMI, BMI z score and weight in children aged 6 to 11 years. The evidence suggests a very low occurrence of adverse events. The quality of the evidence was low or very low. The heterogeneity observed across all outcomes was not explained by subgrouping. Further research is required of behaviour-changing interventions in lower income countries and in children from different ethnic groups; also on the impact of behaviour-changing interventions on health-related quality of life and comorbidities. The sustainability of reduction in BMI/BMI z score and weight is a key consideration and there is a need for longer-term follow-up and further research on the most appropriate forms of post-intervention maintenance in order to ensure intervention benefits are sustained over the longer term.

Exercise and BMI z-score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta-Analysis of Randomized Trials

AIM

Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents.

METHODS

Randomized exercise intervention trials ≥ 4 weeks were included. Studies were retrieved by searching six electronic databases, cross-referencing and expert review. Dual selection and abstraction occurred. Risk of bias and confidence in cumulative evidence were assessed. Network meta-analysis was performed using multivariate random-effects meta-regression models while surface under the cumulative ranking curves were used to calculate a hierarchy of exercise treatments. The number needed to treat (NNT) and percentile improvement (U₃ ) were also calculated.

RESULTS

Thirty-four studies representing 2,239 participants were included. Median exercise occurred 3 times per week, 50 minutes per session over a 12-week period. Statistically significant reductions in BMI z-score were found for aerobic exercise and combined aerobic and strength exercise, but not strength training alone (M±SD, 95% CI: aerobic, -0.10, -0.15 to -0.05; aerobic and strength, -0.11, -0.19 to -0.03; strength, 0.04, -0.07 to 0.15). Combined aerobic and strength training was ranked best, followed by aerobic exercise and strength training. The NNT was 2 for both aerobic exercise and combined aerobic exercise and strength training. Percentile improvements were 28.8% for aerobic exercise and 31.5% for combined aerobic exercise and strength training. Confidence in effect estimates was ranked as low for aerobic exercise and very low for combined aerobic and strength training as well as strength training.

CONCLUSIONS

Aerobic exercise and combined aerobic exercise and strength training are associated with reductions in BMI z-score.

Improving the health and welfare of people who live in slums

In the first paper in this Series we assessed theoretical and empirical evidence and concluded that the health of people living in slums is a function not only of poverty but of intimately shared physical and social environments. In this paper we extend the theory of so-called neighbourhood effects. Slums offer high returns on investment because beneficial effects are shared across many people in densely populated neighbourhoods. Neighbourhood effects also help explain how and why the benefits of interventions vary between slum and non-slum spaces and between slums. We build on this spatial concept of slums to argue that, in all low-income and-middle-income countries, census tracts should henceforth be designated slum or non-slum both to inform local policy and as the basis for research surveys that build on censuses. We argue that slum health should be promoted as a topic of enquiry alongside poverty and health.

Exercise and BMI in Overweight and Obese Children and Adolescents: A Systematic Review and Trial Sequential Meta-Analysis

OBJECTIVE

Determine the effects of exercise on body mass index (BMI in kg · m(-2)) among overweight and obese children and adolescents.

METHODS

Trial sequential meta-analysis of randomized controlled exercise intervention trials ≥ 4 weeks and published up to November 11, 2014.

RESULTS

Of the 5,436 citations screened, 20 studies representing 971 boys and girls were included. Average length, frequency, and duration of training were 13 weeks, 3 times per week, for 46 minutes per session. Overall, random-effects models showed that exercise decreased BMI by 3.6% (mean: -1.08; 95% CI: -0.52 to -1.64; Q = 231.4; p < 0.001; I (2) = 90.9%; 95% CI: 87.6% to 93.4%; D (2) = 91.5%). Trial sequential meta-analysis showed that changes in BMI crossed the monitoring boundary for a type 1 error in 2010, remaining stable thereafter. The number needed to treat was 5 while the percentile improvement was 26.9. It was estimated that approximately 2.5 million overweight and obese children in the US and 22.0 million overweight and obese children worldwide could reduce their BMI by participating in a regular exercise program. Overall quality of evidence was rated as moderate.

CONCLUSIONS

Exercise is associated with improvements in BMI among overweight and obese children and adolescents. This trial is registered with PROSPERO Trial Registration #CRD42015017586.

How effective are interventions at reducing socioeconomic inequalities in obesity among children and adults? Two systematic reviews

Background

Tackling obesity is one of the major contemporary public health policy challenges and is vital in terms of addressing health inequalities.

Objectives

To systematically review the effectiveness of interventions (individual, community and societal) in reducing socioeconomic inequalities in obesity among (1) children aged 0–18 years (including prenatal) and (2) adults aged ≥18 years, in any setting, in any country, and (3) to establish how such interventions are organised, implemented and delivered.

Data sources

Nine electronic databases including MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, PsycINFO and NHS Economic Evaluation Database were searched from database start date to 10 October 2011 (child review) and to 11 October 2012 (adult review). We did not exclude papers on the basis of language, country or publication date. We supplemented these searches with website and grey literature searches.

Review methods

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Experimental studies and observational studies with a duration of at least 12 weeks were included. The reviews considered strategies that might reduce existing inequalities in the prevalence of obesity [i.e. effective targeted interventions or universal interventions that work more effectively in low socioeconomic status (SES) groups] as well as those interventions that might prevent the development of inequalities in obesity (i.e. universal interventions that work equally along the SES gradient). Interventions that involved drugs or surgery and laboratory-based studies were excluded from the reviews. The initial screening of titles and abstracts was conducted by one reviewer with a random 10% of the sample checked by a second reviewer. Data extraction was conducted by one reviewer and independently checked by a second reviewer. The methodological quality of the included studies was appraised independently by two reviewers. Meta-analysis and narrative synthesis were conducted focusing on the ‘best-available’ evidence for each intervention type (defined in terms of study design and quality).

Results

Of 56,967 papers of inequalities in obesity in children, 76 studies (85 papers) were included, and of 70,730 papers of inequalities in obesity in adults, 103 studies (103 papers) were included. These studies suggested that interventions that aim to prevent, reduce or manage obesity do not increase inequalities. For children, there was most evidence of effectiveness for targeted school-delivered, environmental and empowerment interventions. For adults, there was most evidence of effectiveness for primary care-delivered tailored weight loss and community-based weight loss interventions, at least in the short term among low-income women. There were few studies of appropriate design that could be included on societal-level interventions, a clear limitation of the evidence base found.

Limitations

The reviews located few evaluations of societal-level interventions and this was probably because they included only experimental study designs. The quality assessment tool, although described as a tool for public health interventions, seemed to favour those that followed a more clinical model. The implementation tool was practical but enabled only a brief summary of implementation factors to be made. Most of the studies synthesised in the reviews were from outside the UK and related to women.

Conclusions

The reviews have found some evidence of interventions with the potential to reduce SES inequalities in obesity and that obesity management interventions do not increase health inequalities. More experimental studies of the effectiveness and cost-effectiveness of interventions (particularly at the societal level) to reduce inequalities in obesity, particularly among adolescents and adult men in the UK, are needed.

Study registration

The studies are registered as PROSPERO CRD42011001740 and CRD42013003612.

Funding

The National Institute for Health Research Public Health Research programme.

A systematic review of the effectiveness of individual, community and societal level interventions at reducing socioeconomic inequalities in obesity amongst children

BACKGROUND

Tackling childhood obesity is one of the major contemporary public health policy challenges and vital in terms of addressing socioeconomic health inequalities.We aimed to systematically review studies of the effectiveness of interventions (individual, community and societal) operating via different approaches (targeted or universal) in reducing socio-economic inequalities in obesity-related outcomes amongst children.

METHODS

Nine electronic databases were searched from start date to October 2012 along with website and grey literature searches. The review examined the best available international evidence from interventions that aimed to prevent obesity, treat obesity, or improve obesity-related behaviours (diet and/or physical activity) amongst children (aged 0-18 years) in any setting and country, so long as they provided relevant information and analysis on both socioeconomic status and obesity-related outcomes. Data extraction and quality appraisal were conducted using established mechanisms and narrative synthesis was conducted.

RESULTS

We located 23 studies that provided the 'best available' (strongest methodologically) international evidence. At the individual level (n = 4), there was indicative evidence that screen time reduction and mentoring health promotion interventions could be effective in reducing inequalities in obesity. For the community level interventions (n = 17), evidence was inconclusive - with some studies suggesting that school-based health promotion activities and community-based group-based programmes were effective in reducing obesity - others not. Societal level evaluations were few (n = 1). However, there was no evidence to suggest that any of these intervention types increase inequalities and several studies found that interventions could at least prevent the widening of inequalities in obesity. The majority of studies were from America and were of 6-12 year old children.

CONCLUSIONS

The review has found only limited evidence although some individual and community based interventions may be effective in reducing socio-economic inequalities in obesity-related outcomes amongst children but further research is required, particularly of more complex, societal level interventions and amongst adolescents.

Research potential of food and nutrition in the Family Health Strategy: A structured review

OBJECTIVE: Determine the profile of research groups and publications with food and nutrition-related actions promoted by the Family Health Strategy in Brazil since 1994. METHODS: Two procedures were used: structured review and research group search. The former searched the databases Web of Science, Medline, Lilacs, SciELO and Embase, and followed the principles that guide systematic reviews in the Cochrane Collaboration. The references of the selected articles were also consulted. The research groups were searched in the Research Group Directory of the National Council for Scientific and Technological Development. RESULTS: A total of 54 articles published between 2002 and 2012 in 20 different journals were identified. Ten of these were retrieved from the references section of other articles. Focusing mostly on children from the Southeast region, these studies were coordinated by dieticians, nurses, and physicians. Diabetes Mellitus, high blood pressure, and breastfeeding were the most common topics (n=23). The quantitative methodology was employed by 42 articles, most about diagnoses. Only five research groups studied the Family Health Strategy, despite the growing number of studies in the area over the years. CONCLUSION: Despite the growing scientific production, the findings of this structured review indicate that few studies focused on food and nutrition in the Family Health Strategy, probably because of the existence of few research groups in the country. More comprehensive and consistent studies on the topic are needed.

School-based programs aimed at the prevention and treatment of obesity: evidence-based interventions for youth in Latin America

BACKGROUND

Rapidly rising childhood obesity rates constitute a public health priority in Latin America which makes it imperative to develop evidence-based strategies. Schools are a promising setting but to date it is unclear how many school-based obesity interventions have been documented in Latin America and what level of evidence can be gathered from such interventions.

METHODS

We performed a systematic review of papers published between 1965 and December 2010. Interventions were considered eligible if they had a school-based component, were done in Latin America, evaluated an obesity related outcome (body mass index [BMI], weight, %body fat, waist circumference, BMI z-score), and compared youth exposed vs not exposed.

RESULTS

Ten studies were identified as having a school-based component. Most interventions had a sample of normal and overweight children. The most successful interventions focused on prevention rather than treatment, had longer follow-ups, a multidisciplinary team, and fewer limitations in execution. Three prevention and 2 treatment interventions found sufficient improvements in obesity-related outcomes.

CONCLUSIONS

We found sufficient evidence to recommend school-based interventions to prevent obesity among youth in Latin America. Evidence-based interventions in the school setting should be promoted as an important component for integrated programs, policies, and monitoring frameworks designed to reverse the childhood obesity in the region.

Interdisciplinary intervention in obese children and impact on health and quality of life

OBJECTIVE

To verify the effects of an intervention program including physical exercise and recreational activities, as well as nutritional counseling, on the health-related quality of life of obese children.

METHODS

This was a controlled clinical trial. The initial study population included children aged eight to 11 years with a body mass index (BMI) > 97th percentile for age and gender, according to the criteria of the World Health Organization, totaling 44 children matched by gender and age, as case (n = 22) and control groups (n = 22). BMI and self-reported health-related quality of life by Pediatric Quality of Life Inventory were measured before and after 12 weeks of intervention (three times weekly). The control group did not participate in the intervention.

RESULTS

Thirty-two children completed the study (16 in each group). The case group showed significant reduction in BMI (p = 0.001) and improved quality of life in the physical (p = 0.001), emotional (p = 0.014), social (p = 0.004), and psychosocial (p = 0.002) domains, as well as in overall quality of life (p = 0.001), which was not observed in the control group.

CONCLUSION

The program was effective in improving the health and quality of life of obese children.

Weight-related child behavioral interventions in Brazil: a systematic review

CONTEXT

Between 1974 and 1997, the prevalence of overweight increased 300% among Brazilian children and adolescents. A systematic review was conducted between January 2010 and December 2011 of obesity-related interventions targeting Brazilian children and adolescents.

EVIDENCE ACQUISITION

Manuscripts from 1965 to December 2010 were evaluated based on inclusion criteria including evaluating obesity-related outcomes and at least 50% of participants living in Brazil. Methods were adapted from the CDC's Community Guide. Evidence was based on the number of available studies, study design, execution, quality, and effect size.

EVIDENCE SYNTHESIS

Sixteen articles were abstracted; five met final inclusion criteria. All intervention samples (range n=14-78; mean n=40.6) included overweight or obese children aged 8-17 years. The intervention duration range was 3-6 months, and dose frequency ranged from two to five times per week. Three of the five interventions included healthy eating and physical activity; two included only physical activity. Two interventions studies were rated as having greatest design suitability. Only one intervention had the greatest design suitability and a large effect size.

CONCLUSIONS

Intervention approaches that combined physical activity and healthy eating had the strongest effects. However, small sample bias, 95% CIs of primary effects, and poor-to-moderate quality of research designs and implementation suggest the combined evidence is best rated as Insufficient. This prohibits the recommendation of specific strategies or settings. Findings suggest that more well-designed evidence-based childhood obesity interventions in Brazil are needed and that promising, but yet unproven, interventions should be evaluated rigorously.

Interventions for preventing obesity in children

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 that governments, communities and families can implement to prevent obesity, and promote health, has been accumulating but remains unclear.

OBJECTIVES

This review primarily aims to update the previous Cochrane review of childhood obesity prevention research and determine the effectiveness of evaluated interventions intended to prevent obesity in children, assessed by change in Body Mass Index (BMI). Secondary aims were to examine the characteristics of the programs and strategies to answer the questions "What works for whom, why and for what cost?"

SEARCH METHODS

The searches were re-run in CENTRAL, MEDLINE, EMBASE, PsychINFO and CINAHL in March 2010 and searched relevant websites. Non-English language papers were included and experts were contacted.

SELECTION CRITERIA

The review includes data from childhood obesity prevention studies that used a controlled study design (with or without randomisation). Studies were included if they evaluated interventions, policies or programs in place for twelve weeks or more. If studies were randomised at a cluster level, 6 clusters were required.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of included studies.  Data was extracted on intervention implementation, cost, equity and outcomes. Outcome measures were grouped according to whether they measured adiposity, physical activity (PA)-related behaviours or diet-related behaviours.  Adverse outcomes were recorded. A meta-analysis was conducted using available BMI or standardised BMI (zBMI) score data with subgroup analysis by age group (0-5, 6-12, 13-18 years, corresponding to stages of developmental and childhood settings).

MAIN RESULTS

This review includes 55 studies (an additional 36 studies found for this update). The majority of studies targeted children aged 6-12 years.  The meta-analysis included 37 studies of 27,946 children and demonstrated that programmes were effective at reducing adiposity, although not all individual interventions were effective, and there was a high level of observed heterogeneity (I(2)=82%).  Overall, children in the intervention group had a standardised mean difference in adiposity (measured as BMI or zBMI) of -0.15kg/m(2) (95% confidence interval (CI): -0.21 to -0.09).  Intervention effects by age subgroups were -0.26kg/m(2) (95% CI:-0.53 to 0.00) (0-5 years), -0.15kg/m(2) (95% CI -0.23 to -0.08) (6-12 years), and -0.09kg/m(2) (95% CI -0.20 to 0.03) (13-18 years). Heterogeneity was apparent in all three age groups and could not explained by randomisation status or the type, duration or setting of the intervention.  Only eight studies reported on adverse effects and no evidence of adverse outcomes such as unhealthy dieting practices, increased prevalence of underweight or body image sensitivities was found.  Interventions did not appear to increase health inequalities although this was examined in fewer studies.

AUTHORS' CONCLUSIONS

We found strong evidence to support beneficial effects of child obesity prevention programmes on BMI, particularly for programmes targeted to children aged six to 12 years. However, given the unexplained heterogeneity and the likelihood of small study bias, these findings must be interpreted cautiously. A broad range of programme components were used in these studies and whilst it is not possible to distinguish which of these components contributed most to the beneficial effects observed, our synthesis indicates the following to be promising policies and strategies:·         school curriculum that includes healthy eating, physical activity and body image·         increased sessions for physical activity and the development of fundamental movement skills throughout the school week·         improvements in nutritional quality of the food supply in schools·         environments and cultural practices that support children eating healthier foods and being active throughout each day·         support for teachers and other staff to implement health promotion strategies and activities (e.g. professional development, capacity building activities)·         parent support and home activities that encourage children to be more active, eat more nutritious foods and spend less time in screen based activitiesHowever, study and evaluation designs need to be strengthened, and reporting extended to capture process and implementation factors, outcomes in relation to measures of equity, longer term outcomes, potential harms and costs.Childhood obesity prevention research must now move towards identifying how effective intervention components can be embedded within health, education and care systems and achieve long term sustainable impacts.