The long-term effects of primary school-based obesity prevention interventions in children: A systematic review and meta-analysis

Randomized controlled trials on physical activity, diet, or both for public health through body weight management in 5- to 10-year-old pupils: a systematic review and meta-analysis

Improving the quality of the most basic health behavior among youth may contribute to short-term body composition management with long-term implications for noncommunicable disease regression. This investigation aimed to assess the impact of primary school physical activity (PA), dietary, or dual approach interventions on pupils' body weight (BW) and body mass index (BMI). A systematic review and meta-analysis was completed following a study protocol and a trial registration (PROSPERO: CRD4202347770) with the PRISMA approach. Publications in English or German were included with school-based randomized controlled trials on diet and/or PA. Pupils of primary schools (aged 5-10) with no major nutritional deficiency or unstable health condition were included. The Boolean search strategy revealed a total of 9479 articles, qualifying 39 studies with 20 462 pupils (including 10 211 girls and 10 251 boys) for quantitative synthesis. The interventions were mostly PA (n = 31), several were dietary (n = 6), and some were dual approach (n = 5). Random effects meta-analyses revealed PA intervention (n = 20) to have an effect size of +0.07 kg (95% CI: -0.01 to 0.15) and -0.12 kg/m2 (95% CI: -0.23 to -0.01). Low statistical heterogeneity was found for BW (I2 = 0%; P = 1.000) and BMI (I2 = 0%; P = .9688), respectively. The findings indicate a scarcity of top-quality scientific research performed on healthy diet for body weight management in primary schools. PA intervention for elementary school pupils provides support for a healthier body composition profile amidst the current world health crisis.

Long-term effects of a primary school-based overweight preventive intervention on physical fitness and physical activity: a propensity score-matched retrospective cohort study within the Generation R Study

OBJECTIVES

In this study, we evaluate the long-term effects (±1.5 years postintervention) of 6-year exposure to the Lekker Fit! intervention on physical fitness and physical activity (PA).

DESIGN

The retrospective intervention evaluation is embedded within the Generation R Study in Rotterdam, the Netherlands, a population-based prospective birth cohort study.

SETTING

Measurements took place in the research centre of the Generation R cohort study.

PARTICIPANTS

5489 adolescents from the Generation R Study were eligible for inclusion within this study. Successful linking to school career data was possible for 4129 adolescents who were then retrospectively subdivided into a Lekker Fit! group, mixed group and regular school group based on their primary school career.

INTERVENTIONS

The Lekker Fit! intervention is a multicomponent primary school-based intervention for the prevention of overweight. It focuses on a healthy diet and healthy lifestyle rather than focusing directly on the reduction of overweight. The intervention targets individual behaviour of children as well as their obesogenic environment and parental engagement in shaping their children's behaviour.

PRIMARY AND SECONDARY OUTCOME MEASURES

Aged 13/14 years old, physical fitness was measured with an incremental ergometer test. The actual highest achieved work rate was divided by the expected highest achieved work rate (age- and sex-related Dutch population-based reference data), and converted into z-scores. PA was determined by the number of days with at least 1 hour of PA, obtained by a self-reported questionnaire. Propensity score matching was performed to correct for non-random selection bias. Linear regression analyses were performed to estimate intervention effects.

RESULTS

Children from the Lekker Fit! group had significantly lower fitness z-scores (-0.18 (95% CI -0.29 to -0.06), n=1826) compared with children from the matched regular school group. No Lekker Fit! intervention effect was found on PA (-0.12 (95% CI -0.36 to 0.12), n=1258).

CONCLUSIONS

No evidence was found for long-term favourable effects of a school-based multicomponent intervention on physical fitness and PA. Recommendations for policy and future research are discussed.

The long-term effects of a school-based intervention on preventing childhood overweight: Propensity score matching analysis within the Generation R Study cohort

BACKGROUND

This study investigated the long-term impact of the primary school-based multicomponent lifestyle intervention "Lekker Fit!" (LF) on obesity-related outcomes, and studied whether the impact differed between population subgroups.

METHODS

Children from the Generation R Study (Rotterdam, the Netherlands) were categorized into the LF group (6 years exposure, between the ages 6/7 to 12/13 years) or regular school group (no exposure). BMI and DXA-derived fat mass were assessed after 4 years of intervention (age 10 years), and 1.5 years post-intervention (age 14 years). A propensity score matching model was fitted to examine the intervention effect on BMI-z-score and percent fat mass, and we tested for differences by sex, pre-intervention weight status, ethnic background, and income.

RESULTS

We found no effect on BMI-z-score [0.06 (95% confidence interval [CI]: -0.04 to 0.17)] and percent fat mass (0.4%-point [95% CI: -0.2 to 1.1]) after 4 years of intervention. 1.5 years post-intervention and after 6 years of exposure, BMI-z-score (0.11 [95% CI: 0.00-0.22]) and percent fat mass (1.1%-point [95% CI: 0.2-1.9]) were significantly higher for children in the LF group. No subgroup differences were found.

CONCLUSION

Findings suggest the need for obesity prevention programs that extend beyond primary education.

Long-term follow-up of the impact of brief sleep and lifestyle interventions in infancy on BMI z-score at 11 years of age: The POI randomized controlled trial

OBJECTIVE

To determine whether BMI differences observed at 5 years of age, from early intervention in infancy, remained apparent at 11 years.

METHODS

Participants (n = 734) from the original randomized controlled trial (n = 802) underwent measures of body mass index (BMI), body composition (DXA), sleep and physical activity (24-h accelerometry, questionnaire), diet (repeated 24-h recalls), screen time (daily diaries), wellbeing (CHU-9D, WHO-5), and family functioning (McMaster FAD) around their 11th birthday. Following multiple imputation, regression models explored the effects of two interventions ('Sleep' vs. 'Food, Activity and Breastfeeding' [FAB]) using a 2 × 2 factorial design.

RESULTS

Five hundred twelve children (48% female, mean [SD] age 11.1 [0.1] years) returned for the 11-year assessment (63% of original sample). Significant differences in BMI z-score (mean difference; 95% CI: -0.16; -0.41, 0.08) or the risk of overweight (including obesity) (odds ratio; 95% CI: 0.85; 0.56, 1.29) were no longer observed between children who had received the sleep intervention compared with those who had not. By contrast, children who had received the FAB intervention had greater BMI z-scores (0.24; 0.01, 0.47) and a higher risk of obesity (1.56; 1.03, 2.36) than children not enrolled in FAB. No significant differences were observed in any lifestyle variables nor wellbeing measures across all groups.

CONCLUSIONS

Sustained reductions in BMI and obesity risk from an early sleep intervention were not apparent 9 years later, whereas a more traditional lifestyle intervention resulted in increased rates of obesity, not explained by any differences in lifestyle behaviours measured.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov number NCT00892983, https://clinicaltrials.gov/study/NCT00892983.

Effectiveness of a health promotion program on overweight in vulnerable children from primary schools (BeE-school): A cluster-randomized controlled trial

BACKGROUND

Obesity is a complex, multifactorial disease with rising global prevalence. Considering its significant association with lower socioeconomic status, implementing obesity prevention programs in vulnerable school-age children is particularly pertinent. This cluster-randomized controlled trial aims to evaluate the effectiveness of a health promotion program on overweight in vulnerable children from primary schools.

METHODS

The BeE-school study involved 735 children (51.7% boys, average age 7.7 (1.2) years old) from 10 primary schools in the Northern region of Portugal, identified as Educational Territories for Priority Intervention. After the initial assessment, the schools were randomized into two groups: one receiving the intervention (4 schools, n = 353) and the other not (6 schools, n = 382). The intervention included education and training teachers for 16 weeks, their implementation in the classroom, and giving families challenges every two weeks during this length of time. The program's effectiveness was assessed short-term, immediately post-intervention (for 95.5% of participants) and long-term, one year after (for 50.8%). We considered the difference in BMI z-scores (BMIz), waist-to-height ratio and waist-to-weight ratio, from baseline to post-intervention and follow-up assessment.

RESULTS

In post-intervention, intervened children presented a significant reduction in all the three measures of adiposity: BMIz (B = -0.098, 95% CI: -0.156 to -0.040, p = 0.001), waist-to-height ratio (B = -0.007, 95% CI: -0.010 to -0.003, p < 0.001) and waist-to-weight ratio (B = -0.121, 95% CI: -0.193 to -0.048, p = 0.001). One year after the intervention ended the decrease in BMIz remained significant (B = -0.114, 95% CI: -0.213 to -0.015, p = 0.023).

CONCLUSION

Conclusion: The school-based intervention, focusing on teacher training in health promotion and involving families, proved to be effective in improving body composition in socially vulnerable children.

Appetite Self-Regulation in Childhood: A Narrative Review and Conceptual Model of Processes and Mechanisms With Implications for Research and Practice

The purpose of the present narrative review was to propose a unifying generalized conceptual model of mechanisms and processes in appetite self-regulation (ASR) in childhood. Appetite self-regulation, along with other domains of self-regulation, develops across childhood and contributes to energy intake and balance, diet quality, weight, and therefore long-term health outcomes. There have been efforts to conceptualize and measure components of ASR and associated processes/mechanisms, but, at present, there is no unifying conceptualization of ASR in childhood. A search of key databases supplemented by snowballing was undertaken for definitions/conceptions and theoretical models of ASR with a focus on children. An interpretive synthesis approach was used to identify themes from the definitions and models. The themes formed the basis of the proposed unifying generalized model of ASR in childhood, which is the main contribution of the article. At the center of the model is bottom-up reactivity to food, food cues and hunger, satiation and satiety signals, together with top-down regulatory control. An additional contribution is the proposed 5 interacting and overlapping domains (biological, hedonics, cognitive, behavioral, and traits) that function in and influence both bottom-up reactivity and top-down regulation. The domains also contribute to ASR outcomes of enactment and competence. External contextual and intrapersonal factors are conceived as impacting the domains and the bottom-up, top-down processes. The relevance of the model for explanations of ASR phenomena in childhood and children's food choice and diet quality, as well as its implications for research directions and approaches to preventive intervention, including food parenting practices, are discussed. The model provides a framework for researchers and practitioners to support and interpret children's problems and competence in self-directing food choices, energy intake, and nutrition.

Comparative effectiveness of school-based obesity prevention programs for children and adolescents: a systematic review and network meta-analysis

Introduction

While many randomized controlled trials (RCTs) have demonstrated the positive effects of school-based programs in reducing body fat among children and teenagers, there is no conclusive evidence to indicate that one approach is superior to another, largely due to the lack of direct and indirect comparisons. This study evaluated the relative effectiveness of various school-based obesity prevention initiatives in improving body mass index (BMI) among children and adolescents using network meta-analysis.

Methods

Searches included four databases focusing on articles published in English between the years 2002 and 2024. The primary outcomes were the BMI and BMI z-scores (BMIz) (kg/m2). The mean differences (MDs) for each outcome were calculated before and after treatment. The current systematic review synthesized 53 RCTs with a sample of 68,489 children and adolescents.

Results

The results illustrated that the physical activity (PA) only arm was the most effective intervention in improving BMI (MD: -0.42, 95% credible interval (Crl) -0.79, -0.07; p = 0.02), while the multiple-component intervention was the most effective in improving BMIz (MD: -0.08, 95% Crl: -0.16, -0.01; p = 0.03). Inversely, PA and another component arm were the least effective interventions in improving BMI (MD: 0.64, 95% Crl: -0.23, 1.53; p = 0.15). In addition, diet and nutrition only arm was the least effective intervention in improving BMIz (MD: 0.09, 95% Crl: -0.11, 0.28; p = 0.36).

Discussion

In conclusion, both PA-only and multiple-component arms are effective intervention tools/strategies for reducing BMI-related outcomes. However, further large-scale, well-designed studies are needed to investigate the elements of multiple-component arms.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/ identifier CRD42021234742.

Exploring the Effect of an Obesity-Prevention Intervention on Various Child Subgroups: A Post Hoc Subgroup Analysis of the Kiel Obesity Prevention Study

BACKGROUND

This study investigated potential subgroups of children within the Kiel Obesity Prevention Study (KOPS) for differing treatment effects for the outcome measures of overweight or obesity at 4 years. The KOPS study delivered a multicomponent school intervention to cohorts of children in Kiel but found no overall effect on the weight status outcome. However, KOPS authors suggested there may be subgroup variations in treatment effect. Data were collected as part of the KOPS for samples of 6-year-olds between 1996 and 2001, with 4-year follow-up measurements between 2000 and 2004.

METHODS

The present study conducted a post hoc subgroup analysis of the odds of obesity or overweight at 4-year follow-up compared to normal weight (n = 1646). A generalized linear mixed-effects model, including a treatment-subgroup interaction term, was used to estimate subgroups as a moderator of the treatment effects on the outcomes of obesity or overweight at 4-year follow-up.

RESULTS

The findings indicated several subgroup-treatment interaction effects relating to physical activity indicators. TV or PC not being one of a child's top 3 activities at baseline was associated with a significantly decreased odds ratio of obesity at 4 years in the intervention group (OR, 0.04; 95% CI, 0.004 to 0.45) compared to the non-intervention group (OR, 0.96; 95% CI, 0.29 to 3.14), p = 0.02. Weekly activity in a sports club at baseline was associated with a decreased odds ratio of overweight at 4 years in the intervention group (OR, 0.38; 95% CI, 0.16 to 0.85) compared to the non-intervention group (OR, 0.91; 95% CI, 0.70 to 1.17). This was a significant difference (p = 0.04).

CONCLUSIONS

These findings suggest that children's baseline physical activity may impact treatment effects on the outcomes of overweight and obesity, creating opportunities to increase the effectiveness of interventions on preventing obesity.

Baseline higher hair cortisol moderated some effects in a healthy lifestyle intervention

Children and families from socioeconomically marginalized background experience high levels of stress, especially persistent chronic stress, due to unstable housing, employment, and food insecurity. Although consistent evidence supports a stress-obesity connection, little research has examined the potential moderation role of stress in childhood obesity interventions. Therefore, this study aimed to explore how chronic stress (hair cortisol) moderated the effects of a healthy lifestyle intervention on improving behavioral and anthropometric outcomes among 95 socioeconomically marginalized parent-child dyads. Data were collected in a cluster randomized controlled trial with 10 Head Start childcare centers being randomized into intervention and control. The child sample (3-5 years old) included 57.9 % female, 12.6 % Hispanic, and 40.0 % Black. For the parents, 91.6 % were female, 8.4 % were Hispanic, 36.8 % were Black, and 56.8 % were single. Parent baseline hair cortisol significantly moderated the intervention effects on child fruit intake (B = -1.56, p = .030) and parent nutrition self-efficacy (B = 1.49, p = .027). Specifically, higher parent hair cortisol lowered the increases in child fruit intake but improved the increases in parent nutrition self-efficacy in the intervention group compared to control group. Child higher baseline hair cortisol was significantly associated with the decreases in child fruit intake (B = -0.60, p = .025). Child baseline hair cortisol significantly moderated the intervention effects on parent physical activity (PA) self-efficacy (B = -1.04, p = .033) and PA parental support (B = -0.50, p = .016), with higher child hair cortisol decreasing the improvement on these two outcomes in the intervention group compared to control group. Results from this study shed lights on the moderation role of chronic stress on impacting healthy lifestyle intervention effects. Although needing further investigation, the adverse effects of chronic stress on intervention outcomes should be considered when developing healthy lifestyle interventions for preschoolers and their families.

Long-Term Effects of a Primary Weight Gain Prevention Intervention among Healthy Weight Obesity Susceptible Children: Results from the Healthy Start Study

INTRODUCTION

Primary prevention is a public health strategy that hitherto has not been widely applied in obesity prevention research. The objectives were to examine the long-term effects of the Healthy Start primary obesity prevention study, an intervention conducted among healthy weight children susceptible to develop obesity.

METHODS

At baseline, children (2-6 years) were allocated to the intervention group (n = 271), the control group (n = 272), or the shadow control group (n = 383). Children in the shadow control group had no contact with project staff during the intervention period (1.3 years on average). The intervention was designed to deliver individually tailored improvements in diet and physical activity habits, optimization of sleep quantity and quality and reduce family stress. After the intervention was completed, height and weight at school entry were obtained from the Danish National Child Health Register when children were around 7 years. The average follow-up time was 2.7 years after baseline. Linear regression analyses on annual changes in BMI (ΔBMI) and BMI z-scores (ΔBMIz) were conducted.

RESULTS

At mean 2.7 years after the baseline examination, no differences were observed between the intervention and control group in ΔBMI (β = 0.07 [-0.02; 0.15], p = 0.14) or ΔBMIz (β = 0.04 [-0.02; 0.10], p = 0.19). Likewise, no differences were observed between the intervention and shadow control group in ΔBMI (β = -0.03 [-0.12; 0.06], p = 0.50) or in ΔBMIz (β = -0.02 [-0.08; 0.05], p = 0.62).

CONCLUSION

We are still in urgent need of more primary overweight prevention interventions to begin to understand how to prevent that healthy weight children develop overweight.

Nutrition Interventions for Pediatric Obesity Prevention: An Umbrella Review of Systematic Reviews

Nutrition interventions to prevent pediatric obesity can help to establish healthy habits to improve current and future health. The objective of this umbrella review of systematic reviews (SRs) is to examine the impact of obesity prevention interventions with a nutrition component on body mass index measures, overweight/obesity prevalence, and cost-effectiveness in participants 2-17 years old. Grading of Recommendations Assessment, Development and Evaluation (GRADE) methods were used, and this umbrella review was registered on PROSPERO (CRD42023443033). Included SRs were required to search ≥2 databases and to assess the risk of bias (RoB) of primary studies, and they were published 2017-June 2023. Database searches identified 4776 articles, and 31 SRs were included. In all age groups combined, interventions with both nutrition and physical activity were effective and cost-effective in all settings combined, and in the community setting specifically. In children ≤5 years old, interventions in the home and family, community, and healthcare settings demonstrated some efficacy, whereas in children 6-12 years old, school interventions were most effective. Evidence with individuals 13-17 years was limited. The certainty of evidence was generally low due to RoB in included studies, inconsistency, and imprecision. Pediatric obesity prevention interventions with nutrition should be tailored to the developmental stage to ensure appropriateness and efficacy.