11. SI!
This chapter covers the case study of SI!, a multidimensional school-based obesity prevention intervention in Spain targeting lifestyle behaviour change in 3-5 year-olds. The case study includes an assessment of SI! against the five best practice criteria, policy options to enhance performance and an assessment of its transferability to other OECD and EU27 countries.
Description: the SI! intervention is a multidimensional school-based obesity prevention intervention in Spain which targets lifestyle behaviour change in 3-5 year-olds. The intervention seeks to shape knowledge and attitudes in terms of nutrition, physical activity (PA) and general cardiovascular health. Children are the primary focus of the intervention, but families, teachers and schooling environments are also involved, in order to create a more holistic approach.
Table 11.1. OECD best practice assessment of the SI! intervention | |
|---|---|
Criteria | Assessment |
Effectiveness | The intervention successfully impacted the children’s behaviours, notably in terms of PA, and saw a reduction in anthropometric measurements, although these were at times limited |
Efficiency | Economic evaluations of comparable school-based interventions conclude they are generally cost-effective, and can even be cost-saving |
Equity | The intervention largely targets individuals of low SES, but outcomes were ultimately favourable for children of higher SES |
Evidence-base | Evidence to evaluate SI! is strong in many areas including study design, data collection methods used and control for confounders. However, similar to most public health interventions, neither researchers not participants were blinded. |
Extent of coverage | The intervention in its entirety has relatively extensive coverage, although this is limited in the initial trial |
Enhancement options: to enhance effectiveness, the nutritional quality of foods within schools could be further regulated, and additional PA sessions could be integrated into the school week. To enhance equity, the intervention could be adapted to the specific needs of more vulnerable groups, and key indicators could be broken down by family SES and ethnicity, for example. To enhance the evidence-base, more objective measures could be used in the design and evaluation of the study.
Transferability: the SI! intervention is broadly transferable to other settings within OECD and European countries. For example, it is likely school-based healthy lifestyle interventions will receive political support given obesity is a topic public health issue in most OECD and European countries. However, prior to transfer, policy makers in the target setting should collect important primary data such as level of acceptance amongst teachers and parents.
Conclusion: although data was not available to fully assess the intervention in terms of cost-effectiveness and extent of coverage, the SI! intervention can be considered a best practice in terms of outcomes, compared to the impact of similar multidimensional interventions targeting childhood obesity. To further enhance implementation, intervention administrators could take into consideration policy options laid out in this case study, such as additional monitoring of the food environment.
Cardiovascular diseases (CVD) are a leading cause of death, comprising approximately half of all non-communicable disease (NCD) deaths (Benziger, Roth and Moran, 2016[1]). One of the primary determinants of CVD is obesity, as well as its associated comorbidities (diabetes, hypertension) (Rodríguez-Artalejo et al., 2002[2]). In 2018, almost 60% of people in OECD countries were overweight, and 25% were obese (OECD, 2019[3]). The adoption of unhealthy behaviours leading to the development of CVD risk factors takes place in early childhood (Peñalvo et al., 2013[4]). However, obesity is largely preventable, highlighting the importance of effective health promotion early on in the life course.
The SI! intervention is a school-based multidimensional health intervention in Madrid, Spain, targeting cardiovascular health. It seeks to equip schoolchildren with the behaviours and skills necessary to maintain healthy life habits throughout the life course. The intervention focuses on diet, physical activity (PA), body and heart, and emotional management. The 2011 trial in Madrid studied in this analysis1 included children aged three, four and five years of age and also involved families, teachers and schooling environments. The intervention is delivered over a four-week period every year and is dedicated to teaching children, parents and children about the importance of leading a healthy lifestyle (112 hours in total, 70 of which are dedicated to children) (Peñalvo et al., 2013[4]). On a broader level, the intervention helps promote healthier school and home environments, by working with the canteens, for instance, to design nutritionally adequate menus, or by recommending healthy snacks to the children’s families (20 hours) (Peñalvo et al., 2013[4]).
Twenty-four schools in Madrid participated in the 2011 study, with half the schools completing the intervention and the other half being assigned to the control group. The aim of the intervention was to have a positive effect on the schoolchildren’s lifestyle behaviours, as well as on adiposity markers.
This section analyses SI! against the five criteria within OECD’s Best Practice Identification Framework – Effectiveness, Efficiency, Equity, Evidence-base and Extent of coverage (see Box 11.1 for a high level assessment of SI!). Further details on the OECD Framework can be found in in Annex A.
Evidence-base
The primary outcome of SI! evaluated changes in knowledge, habits and attitudes (KHA) of children using a survey delivered by trained paediatric psychologists. Objective outcome measures such as BMI were also collected
The quality of evidence to evaluate the change in KHA and objective outcome measures was “strong” in many areas including the data collection methods used, controlling for confounders and overall study design
Effectiveness
Effect of the intervention on healthy lifestyle behaviours
The results of the SI! Intervention show that the intervention was generally successful in positively impacting the schoolchildren’s knowledge, attitude and habits (KAH) relating to the intervention content across all age groups (Peñalvo et al., 2015[5]). Indeed, all three years had higher overall KAH scores than the control group at every follow-up check. The greatest improvements were seen in terms of physical activity, where the KAH was consistently higher in every age group (Peñalvo et al., 2015[5]). At the one-year follow-up for instance, knowledge, attitudes and habits regarding physical activity were higher in the intervention group than the control by 1.41, 2.10 and 2.52 in KAH scores from baseline for children aged three, four and five years, respectively (Table 11.2). There were also marginal improvements for the dietary component across all years, however, some participants aged four and five showed no difference in KAH scores. Despite the overall positive impact of the intervention, there were little to no changes in terms of the KAH scores relating to body and heart, further, they were not statistically significant (Peñalvo et al., 2015[5]). Further, data was not available in year two for those aged five and in year three for those aged four or five.
Effect of the intervention on adiposity markers
The SI! intervention had marginal effects on adiposity markers, but these were more significant than the results of similar studies. Due to the duration of the trial, the greatest overall change in anthropometric measurements was seen for those aged three years. There were no significant differences observed in either the one-year (five years of age) or the two-year (four years of age) groups. The waist circumference was in fact lower for the control than the intervention group at the three year follow-up, but this result was not statistically significant (p = 0.179) (Peñalvo et al., 2015[5]). Nonetheless, 1.1% of children in the intervention group were considered obese and 7% overweight by the end of the intervention, versus 1.3% and 7.4% in the control group, respectively (Peñalvo et al., 2015[5]). The effects in terms of BMI and subscapular skinfold (to assess body fat) were minimal, but the results were still favourable towards the intervention group throughout (Peñalvo et al., 2015[5]). Finally, the z-score (the median value of the reference population) for tricep skinfold and waist circumference was more likely to decline by at least 0.1 in the intervention group2 (Peñalvo et al., 2015[5]).
The results of this trial are more significant than those of comparable studies. Very few interventions of two years duration or less have had any positive impact on children’s anthropometric measurements (Peñalvo et al., 2015[5]). The Healthy Study in the United States, a similar three-year multidimensional intervention targeting childhood obesity in 11-year-olds, for instance, did not alter the incidence or prevalence of obesity in either the intervention or control group, nor the remission of overweight or obesity (Foster et al., 2008[6]). Similarly, the CATCH study, a comparable three-year multifaceted intervention targeting children’s cardiovascular health also in the United States, did not record successful outcomes in terms of cholesterol measures, blood pressure or body size (Luepker, 1996[7]). Finally, the ToyBox-study, a school-based intervention seeking to prevent childhood obesity in six European countries did not have any significant impact on the prevalence of obesity or overweight amongst the participants (Miguel-Berges et al., 2019[8]). However, the study did nonetheless lead to an increase in physical activity amongst Belgian schoolchildren (De Craemer et al., 2014[9]). These results point to the potential of the SI! intervention and the importance of long-term comprehensive health promotion interventions early in life.
Efficiency
The OECD’s 2019 obesity report highlights that the investment in school-based interventions corresponds approximately to its GDP benefit, and that annual savings in health expenditure for this type of intervention across all countries could amount to USD PPP 37 million (EUR 25 million) (OECD, 2019[3]). Moreover, the average yearly cost per capita for school-based interventions in Spain is USD PPP 3.05 (EUR 2.09), and these interventions could save USD PPP 0.18 (EUR 0.12) per capita in health expenditure annually.
It is possible that the SI! intervention is cost-effective given that it is comparable to other cost-effective school-based childhood obesity interventions. According to the Join Action on Nutrition and Physical Activity (JANPA), the SI! intervention’s overall budget was under EUR 50 000 per year. No additional data on the cost-effectiveness of the intervention was available. However, comparable multicomponent school-based obesity prevention interventions were generally found to be cost-effective or even cost-saving (Zanganeh et al., 2019[10]). A school-based nutrition and PA intervention including children and their parents in Germany, for example, achieved costs of EUR 11.11 (USD PPP 16.24) for each centimetre reduction in waist circumference (Kesztyüs et al., 2011[11]). The overall intervention generally presented favourable cost-effectiveness ratios (Kesztyüs et al., 2011[11]). Finally, a comprehensive PA intervention in schools in Australia reached cost-effectiveness ratios of AUD 1 408 (USD PPP 978) per BMI unit avoided and AUD 563 (USD PPP 391) per 10% reduction in BMI z-score (Sutherland et al., 2016[12]).
Equity
The SI! intervention can be said to focus on people living in conditions of disadvantage. Indeed, it was specific in selecting the schools in the intervention according to socio-economic criteria. These stipulated that 10-32% of the schoolchildren had to be from an immigrant background, 36-54% had to be receiving free or subsidised school meals and 13-20% had to be receiving free school books and materials.
However, the results showed that the variations in overall KAH score were related to parental socio-economic variables (p for interaction < 0.05). Children whose parents had at least a high school diploma had a higher KAH score on average (p for interaction < 0.001) (Peñalvo et al., 2015[5]). This was also the case for children whose parents earned more than the minimum annual wage in Spain (p for interaction < 0.001) and who were of European origin (p < 0.001) (Peñalvo et al., 2015[5]). No significant variations were observed according to parental age.
Evidence-base
The trial of the SI! intervention was set up as a cluster-RCT open label intervention (where information is not withheld from trial participants). These types of studies are generally preferable as the randomisation element reduces the possibility of bias. The selected 24 schools were allocated on a random basis to the intervention or control group. Moreover, the schools were randomised on a stratified basis by immigration and scholarship percentage in order to guarantee an overall cultural and socio-economic balance amongst the groups (Peñalvo et al., 2015[5]).
Using the Quality Assessment Tool for Quantitative Studies, the design of the study to evaluate SI! was rated as “strong” in several areas: selection, bias, study design, confounders and data collection methods (Effective Public Health Practice Project, 1998[13]). However, similar to many public health interventions, neither researchers nor participants were blinded therefore the study was rated as “weak” against this section. Details of the assessment are in Table 11.3.
Extent of coverage
Information on participation rates is not publically available and has therefore not been possible to assess. However, if scaled-up to a national level, this type of intervention has the potential to cover a large part of the target population. Indeed, it focuses on children who are of age to be in compulsory education, and in EU27 and OECD countries, in general, school participation rates are virtually universal.
The design of SI! fits many of the overarching success factors in terms of school-based childhood obesity prevention interventions (Box 11.2). The trial was a multidimensional intervention aimed at generating long-term lifestyle behaviour change amongst schoolchildren. It provided training and support for teachers, parental activities and promoted healthy diet and PA behaviours within schools by positively impacting the school community. Moreover, the content of the intervention was integrated into the curriculum to minimise the burden on schools.
This box lists several success factors related to obesity interventions in schools. The list draws upon the WHO’s Nutrition Friendly Schools Initiative, however, it is not exhaustive. For further details on WHO’s Nutrition Friendly Schools Initiative, see: https://apps.who.int/iris/handle/10665/338781
Long duration: a systematic review of school-based nutrition education programs found interventions that last longer than one year were more likely to demonstrate effectiveness (Silveira et al., 2011[14]). These results are supported by an earlier meta-analysis which found school-based obesity interventions implemented for longer than a year reduced obesity levels (Gonzalez-Suarez et al., 2009[15]).
Holistic approach involving the community: given the complexity of childhood obesity, schools are increasingly moving towards holistic approaches to reducing BMI (often referred to as “comprehensive school health” or “health promoting schools”) (Okely and Hammersley, 2018[16]). Holistic approaches to reducing obesity aim to change the school and community environment in order for the easy choice to be the healthy choice.
Parental involvement: obesity is a complex health issue and requires initiatives implemented in both the school and home environment. The importance of transferring knowledge and skills regarding healthy eating and exercise in schools to the home is supported by a recent article published in the Lancet which found nearly all successful school-based obesity interventions promoted family involvement (Waters et al., 2011[17]; Okely and Hammersley, 2018[16]; Ash et al., 2017[18]).
Training and support for teachers: to successfully implement school-based obesity interventions all staff involved must receive the appropriate training and professional development support and as well as ongoing capacity building and support (Jones et al., 2014[19]).
Enhancing effectiveness
Literature on best practices in this field emphasise the importance of changes within the school. In upscaling or adapting this intervention, consideration could be given to monitoring the food environment, in order to enhance effectiveness. Other policies for intervention administrators to consider include further regulation and improvement of the nutritional quality of foods onsite (e.g. school meals, vending machines, children’s packed lunches). Additional emphasis could also be placed on exercise within schools (e.g. by integrating additional obligatory and voluntary PA sessions throughout the school week). A school-based intervention in Australia, for instance, integrated PA activities into the school framework, which resulted in significantly more moderate-intensity and vigorous-intensity PA (MVPA) amongst the children (27 min more MVPA per week) (Sutherland et al., 2015[20]), and an average decline in BMI by –0.28 kg at 24 months (Hollis et al., 2016[21]). Finally, in line with WHO’s Nutrition-Friendly Schools Initiative (NFSI), SI! administrators should continue (WHO, 2021[22]):
Focusing on increasing parental involvement, for example by promoting face-to-face interaction
Engaging the community, for example, by procuring healthy fruit and vegetables from local suppliers (in line with EU’s Farm to Fork Strategy)
To ensure that teachers receive appropriate training and education to deliver obesity prevention activities.
Enhancing efficiency
Policy makers and programme administrators should prioritise an efficiency study of SI! given this information isn’t currently available. Example efficiency indicators include incremental cost effectiveness ratios using BMI units avoided, reduction in waist circumference (in centimetres) and/or reduction in BMI z-scores as outcomes of interest. For example, ToyBox – another school-based obesity prevention case study (see Chapter 8) – assessed efficiency using incremental cost-effectiveness ratios, specifically the cost per quality-adjusted life year gained.
Enhancing equity
A review of publically available information indicates the SI! Intervention is implemented homogenously. To enhance equity, to the extent possible, SI! administrators are encouraged to undertake a review to determine whether the intervention should be adapted to meet the needs of different vulnerable groups.
Enhancing the evidence base
In order to better understand how different groups of students benefit from the intervention, future evaluations should break down key indicators, for example, by family SES and ethnicity. A richer dataset will ultimately enhance the evidence-base and allow administrators to adapt the intervention to better meet the needs of disadvantaged students.
Future evaluations would benefit from including additional diet-related outcome indicators such as fruit and vegetable consumption (e.g. the proportion of children who consume fruits/vegetables at least once per day).
Enhancing extent of coverage
Information on participation rates are not publically available, nevertheless, high-level policies to boost participation rates in school-based activities are summarised below:
Promoting the intervention with support from government organisations to enhance trust amongst parents. For example, the Good for Kids, Good for Life intervention in New South Wales (Australia) was promoted using a support letter from the State’s Chief Health Officer. Policy makers however should first consider if messaging from government organisations may in fact reduce uptake among disadvantaged groups. For example, there is evidence showing those with a low SES and/or lower level of education are more anxious and suspicious of prevention messaging from public health authorities (Peretti-Watel and Constance, 2009[23]).
Promoting SI! as a healthy behaviour intervention that aims to boost enjoyable physical activity and healthy eating as opposed to obesity prevention. Framing SI! in a positive light may reduce stigma associated with participation.
Increasing efforts to recruit students whose parents are from culturally or linguistically diverse backgrounds given consent may be harder to obtain (for example, by including staff members who are knowledgeable about relevant cultural characteristics).
Promoting the intervention over a sufficiently long time period using colourful, “eye-grabbing” material in conjunction with frequent digital and face-to-face follow-up with parents.
This section explores the transferability of SI! is broken into three components: 1) an examination of previous transfers; 2) a transferability assessment using publically available data; and 3) additional considerations for policy makers interested in transferring SI!.
Previous transfers
SI! has not been transferred outside of Spain, however, school-based interventions targeting obesity are common across OECD and non-OECD European countries.
Transferability assessment
The following section outlines the methodological framework to assess transferability and results from the assessment.
Methodological framework
Details on the methodological framework to assess transferability can be found in Annex A.
Several indicators to assess the transferability of SI! were identified (Table 11.4). Please note, the assessment is intentionally high level given the availability of public data covering OECD and non-OECD European countries.
Results
Data from publically available sources indicate SI! is transferable based on data related to the economic, sector (i.e. early childhood education) and political contexts (Table 11.5). For example, SI! is likely to have political support given most governments have set out a national strategy addressing childhood obesity. Further, spending on early childhood education and care (ECEC) is higher, on average, amongst OECD and non-OECD EU countries compared to Spain (USD PPP 9 729 versus USD PPP 7 759). However, SI! may have a lower extent of coverage in other countries given enrolment rates in ECEC are relatively high in Spain (97% versus 83%, on average, amongst OECD and non-OECD EU countries).
To help consolidate findings from the transferability assessment above, countries have been clustered into one of three groups, based on indicators reported in Table 11.4. Countries in clusters with more positive values have the greatest transfer potential. For further details on the methodological approach used, please refer to Annex A.
Key findings from each of the clusters are below with further details in Figure 11.1 and Table 11.6:
Countries in cluster one have political, economic and sector specific arrangements in place to transfer SI!. Countries in this cluster are therefore less likely to experience issues associated with implementing and operating SI! in their local context.
Countries in cluster two have political and sector specific arrangements in place to transfer this intervention indicating they are also good transfer candidates. However, before transferring the intervention, countries in this cluster would benefit from increasing spending on early childhood education and care (ECEC) to ensure long-term affordability. It is important to note that Spain, which operates SI!, falls under this cluster indicating high levels of ECEC spending, although ideal, is not a pre-requisite.
Remaining countries are in cluster three, which before transferring SI! would benefit from undertaking further analysis to ensure the intervention is affordable and aligns with overarching political priorities.
Note: Bar charts show percentage difference between cluster mean and dataset mean, for each indicator.
Source: WHO (n.d.[24]), “Global Health Observatory”, https://www.who.int/data/gho; OECD (2022[25]), “OECD data: Education”, https://data.oecd.org/education.htm.
New indicators to assess transferability
Data from publically available datasets is not ideal to assess the transferability of SI!, for example, the level of parental engagement in schools. Therefore, Box 11.3 outlines several new indicators policy makers should consider before transferring SI!.
In addition to the indicators within the transferability assessment, policy makers are encouraged to collect data for the following indicators, as well as those outlined within WHO’s “Making every school a health-promoting school” report (WHO, 2021[26]).
Population context
What is the ethnicity and cultural diversity of the target population?
What is the level of acceptability of the intervention amongst parents?
What is the level of health literacy amongst parents? (e.g. knowledge regarding what constitutes health eating, and the impact of healthy eating and exercise on overall health and well-being)
What is the level of parental engagement with schools and teachers?
Sector specific context (early childhood education)
What is the level of acceptability of the intervention amongst teachers and the Head of School?
Does the school have an overarching policy/framework in place to promote healthy lifestyles amongst students?
What is the level of health literacy amongst teachers? (e.g. how comfortable do teachers feel activities part of the intervention?)
Does the school already include healthy lifestyle lessons in the formal curricula?
What types of infrastructure is available in schools for children to be active? (e.g. playgrounds)
How much greenspace is there for children to be physically active in the school environment?
Do kindergartens have access to a canteen on site? Or is food provided by parents?
What are the regulations/legislation regarding data collection from young children?
Over the course of the past three decades, there has been a significant increase in the prevalence of overweight and obesity worldwide. The adoption of inadequate lifestyle behaviours leading to situations of obesity or overweight takes place in early childhood (Peñalvo et al., 2013[27]). The SI! Intervention aims to prevent such habits from forming through a school-based multicomponent intervention.
The results from the study show that intervention has been successful in positively impacting schoolchildren’s healthy lifestyle knowledge, attitude and habits, notably in terms of physical activity, but also in terms of diet. The intervention also achieved reductions in anthropometric measurements in the children, even though these were at times minimal. Although data surrounding cost was not available, comparable interventions have been shown to be cost-effective, and even cost-saving. The quality of evidence used to evaluate the intervention can be considered to be of moderate quality. Furthermore, the coverage of the intervention in its entirety is relatively extensive (children aged 3-16), but its scope was perhaps limited in the initial trial by its focus on children aged 3-5 in the Madrid area. Moreover, the SI! intervention was specific in selecting intervention and control schools according to socio-economic criteria, although the results from the trial highlighted a need to focus more on these variables in the design of the intervention. Finally, the study fit the majority of best practice criteria for obesity prevention interventions in schools, however, further changes, such as incorporating physical activity, could be considered to achieve the intervention’s core objective: reducing obesity and improving overall health among school-aged children.
Based on available information, SI! is considered broadly transferable. For example, the SI! intervention addresses obesity amongst children, which is a top public health priority across a range of OECD and European countries. However, prior to implementation, policy makers in the target setting should collect information on other important indicators, including those outlined in Box 11.4.
Next steps for policy makers and funding agencies to enhance SI! are listed below:
References
[18] Ash, T. et al. (2017), Family-based childhood obesity prevention interventions: A systematic review and quantitative content analysis, BioMed Central Ltd., https://doi.org/10.1186/s12966-017-0571-2.
[1] Benziger, C., G. Roth and A. Moran (2016), The Global Burden of Disease Study and the Preventable Burden of NCD, Elsevier B.V., https://doi.org/10.1016/j.gheart.2016.10.024.
[9] De Craemer, M. et al. (2014), “The effect of a kindergarten-based, family-involved intervention on objectively measured physical activity in Belgian preschool boys and girls of high and low SES: The ToyBox-study”, International Journal of Behavioral Nutrition and Physical Activity, Vol. 11/1, https://doi.org/10.1186/1479-5868-11-38.
[13] Effective Public Health Practice Project (1998), Quality assessment tool for quantitative studies, https://www.nccmt.ca/knowledge-repositories/search/14.
[6] Foster, G. et al. (2008), “A Policy-Based School Intervention to Prevent Overweight and Obesity”, PEDIATRICS, Vol. 121/4, pp. e794-e802, https://doi.org/10.1542/peds.2007-1365.
[15] Gonzalez-Suarez, C. et al. (2009), “School-Based Interventions on Childhood Obesity. A Meta-Analysis”, American Journal of Preventive Medicine, Vol. 37/5, pp. 418-427, https://doi.org/10.1016/j.amepre.2009.07.012.
[21] Hollis, J. et al. (2016), “Effects of a ‘school-based’ physical activity intervention on adiposity in adolescents from economically disadvantaged communities: secondary outcomes of the ‘Physical Activity 4 Everyone’ RCT”, International Journal of Obesity, Vol. 40/10, pp. 1486-1493, https://doi.org/10.1038/ijo.2016.107.
[19] Jones, R. et al. (2014), “School-based obesity prevention interventions: Practicalities and considerations”, Obesity Research and Clinical Practice, Vol. 8/5, pp. e497-e510, https://doi.org/10.1016/j.orcp.2013.10.004.
[11] Kesztyüs, D. et al. (2011), “Economic evaluation of URMEL-ICE, a school-based overweight prevention programme comprising metabolism, exercise and lifestyle intervention in children”, The European Journal of Health Economics, Vol. 14/2, pp. 185-195, https://doi.org/10.1007/s10198-011-0358-3.
[7] Luepker, R. (1996), “Outcomes of a Field Trial to Improve Children’s Dietary Patterns and Physical Activity”, JAMA, Vol. 275/10, p. 768, https://doi.org/10.1001/jama.1996.03530340032026.
[8] Miguel-Berges, M. et al. (2019), “Combined Longitudinal Effect of Physical Activity and Screen Time on Food and Beverage Consumption in European Preschool Children: The ToyBox-Study”, Nutrients, Vol. 11/5, p. 1048, https://doi.org/10.3390/nu11051048.
[25] OECD (2022), OECD data: Education, https://data.oecd.org/education.htm.
[3] OECD (2019), The Heavy Burden of Obesity: The Economics of Prevention, OECD Health Policy Studies, OECD Publishing, Paris, https://doi.org/10.1787/67450d67-en.
[16] Okely, A. and M. Hammersley (2018), School–home partnerships: the missing piece in obesity prevention?, Elsevier B.V., https://doi.org/10.1016/S2352-4642(17)30154-2.
[5] Peñalvo, J. et al. (2015), “The SI! Program for Cardiovascular Health Promotion in Early Childhood”, Journal of the American College of Cardiology, Vol. 66/14, pp. 1525-1534, https://doi.org/10.1016/j.jacc.2015.08.014.
[4] Peñalvo, J. et al. (2013), “A cluster randomized trial to evaluate the efficacy of a school-based behavioral intervention for health promotion among children aged 3 to 5”, BMC Public Health, Vol. 13/1, https://doi.org/10.1186/1471-2458-13-656.
[27] Peñalvo, J. et al. (2013), “The Program SI! intervention for enhancing a healthy lifestyle in preschoolers: first results from a cluster randomized trial”, BMC Public Health, Vol. 13/1, https://doi.org/10.1186/1471-2458-13-1208.
[23] Peretti-Watel, P. and J. Constance (2009), “Comment les fumeurs pauvres justifient-ils leur pratique et jugent-ils la prévention ?”, Déviance et Société, Vol. 33/2, p. 205, https://doi.org/10.3917/ds.332.0205.
[2] Rodríguez-Artalejo, F. et al. (2002), “Dietary patterns among children aged 6-7 y in four Spanish cities with widely differing cardiovascular mortality”, European Journal of Clinical Nutrition, Vol. 56/2, pp. 141-148, https://doi.org/10.1038/sj.ejcn.1601296.
[14] Silveira, J. et al. (2011), Effectiveness of school-based nutrition education interventions to prevent and reduce excessive weight gain in children and adolescents: A systematic review, J Pediatr (Rio J), https://doi.org/10.2223/JPED.2123.
[20] Sutherland, R. et al. (2015), “Physical Activity 4 Everyone: school-based intervention to prevent decline in adolescent physical activity levels: 12 month (mid-intervention) report on a cluster randomised trial”, British Journal of Sports Medicine, Vol. 50/8, pp. 488-495, https://doi.org/10.1136/bjsports-2014-094523.
[12] Sutherland, R. et al. (2016), “Cost effectiveness of a multi-component school-based physical activity intervention targeting adolescents: the ‘Physical Activity 4 Everyone’ cluster randomized trial”, International Journal of Behavioral Nutrition and Physical Activity, Vol. 13/1, https://doi.org/10.1186/s12966-016-0418-2.
[17] Waters, E. et al. (2011), Interventions for preventing obesity in children, John Wiley and Sons Ltd, https://doi.org/10.1002/14651858.CD001871.pub3.
[26] WHO (2021), Making every school a health-promoting school: Global standards and indicators, World Health Organization and the United Nations Educational, Scientific and Cultural Organization, https://www.who.int/publications/i/item/9789240025059.
[22] WHO (2021), Nutrition action in schools: a review of evidence related to the nutrition-friendly schools initiative, https://www.who.int/publications/i/item/9789241516969.
[24] WHO (n.d.), Global Health Observatory, https://www.who.int/data/gho (accessed on 25 August 2021).
[10] Zanganeh, M. et al. (2019), “A Systematic Review of Methods, Study Quality, and Results of Economic Evaluation for Childhood and Adolescent Obesity Intervention”, International Journal of Environmental Research and Public Health, Vol. 16/3, p. 485, https://doi.org/10.3390/ijerph16030485.
Notes
← 1. The SI! intervention in its entirety includes schoolchildren aged 3-16. However, this study focuses exclusively on the pilot trial of the intervention implemented in 2011 amongst children 3-5 years of age, given the lack of available information on other age groups.
← 2. Z-scores reflect the number of standard deviations away from the mean in the reference group (i.e. a z-score of -1 indicates the score is 1 standard deviation below the men).