The association between overweight and opportunity structures in the built environment: a multi-level analysis among elementary school youth in the PLAY-ON study

The Impact of Health Geography on Public Health Research, Policy, and Practice in Canada

The link between geography and health means that the places we occupy-where we are born, where we live, where we work, and where we play-have a direct impact on our health, including our experiences of health. A subdiscipline of human geography, health geography studies the relationships between our environments and the impact of factors that operate within those environments on human health. Researchers have focused on the social and physical environments, including spatial location, patterns, causes of disease and related outcomes, and health service delivery. The work of health geographers has adopted various theories and philosophies (i.e., positivism, social interactionism, structuralism) and methods to collect and analyze data (i.e., quantitative, qualitative, spatial analysis) to examine our environments and their relationship to health. The field of public health is an organized effort to promote the health of its population and prevent disease, injury, and premature death. Public health agencies and practitioners develop programs, services, and policies to promote healthy environments to support and enable health. This commentary provides an overview of the recent landscape of health geography and makes a case for how health geography is critically important to the field of public health, including examples from the field to highlight these links in practice.

The Relationship of Urban Form on Children and Adolescent Health Outcomes: A Scoping Review of Canadian Evidence

Urban form can have an impact on health outcomes in children, and the synthesis of findings can identify gaps in the literature and regional reviews may help guide policymakers. This study aims to complete a scoping review of the research relating urban form to health outcomes in children and adolescents from urban Canadian settings. Thirteen online databases were searched to identify studies that had objective measures of urban form and health outcomes. Two research assistants independently reviewed 27,444 titles and abstracts, and 176 full-text articles, returning 32 unique studies with youth-specific data. The majority of the included studies were cross-sectional or ecological (n = 26). Six studies used Canada-wide data and the rest were from Ontario (n = 11), Alberta (n = 6), and Quebec (n = 6). Urban form characteristics included neighbourhood food environment (n = 11), parks/natural space/greenness (n = 10), road or intersection characteristics (n = 7), and aggregated urban form measures (n = 7). Studies examined a variety of health outcomes: the majority considered weight status (n = 16) and injury (n = 10). Although there is over-reliance on mainly cross-sectional study designs, there is evidence suggesting that urban form is associated with health outcomes in Canadian youth, with parks/greenspace, road connectivity, and road characteristics most consistently associated with health outcomes in youth.

Retail food environment around schools and overweight: a systematic review

CONTEXT

The presence of retail food establishments around schools can be a potentiating or protective factor for overweight in students, depending on access to these places as well as types of foods available therein. The hypothesis for this study was that a greater density and proximity of retail food establishments around schools influence the weight of students.

OBJECTIVE

To systematically review the available observational literature on the association between retail food establishments around schools and the occurrence of overweight and obesity in schoolchildren and adolescents.

DATA SOURCES

Observational studies were searched in the MEDLINE, EMBASE, and SCOPUS databases published until May 2019.

DATA EXTRACTION

Two independent reviewers extracted relevant data.

DATA ANALYSIS

Data on the 31 included studies were summarized with narrative synthesis according to meta-analyses of observational studies in epidemiology, exploring the type of food establishments around schools and analyzing qualitatively the impact of proximity or density on overweight and obesity rates.

CONCLUSION

Of the 31 articles, a direct association between proximity or density of establishments (mainly fast food restaurants, convenience stores, grocery stores) around schools and overweight and obesity in children and adolescents were found in 14 studies. However, authors of 13 papers found no association and inverse association was presented in 4 papers. The studies presented different methods of classification, location, and analysis of retail food establishments, making it difficult to conclude the real influence that the presence of these establishments near schools have on the nutritional status of children and adolescents. Therefore, future studies should consider the use of longitudinal designs and standardized analysis of the food environment around schools to better understand this food environment and its influence on health-related behaviors.

State-of-the-art of measures of the obesogenic environment for children

Various measures of the obesogenic environment have been proposed and used in childhood obesity research. The variety of measures poses methodological challenges to designing new research because methodological characteristics integral to developing the measures vary across studies. A systematic review has been conducted to examine the associations between different levels of obesogenic environmental measures (objective or perceived) and childhood obesity. The review includes all articles published in the Cochrane Library, PubMed, Web of Science and Scopus by 31 December 2018. A total of 339 associations in 101 studies have been identified from 18 countries, of which 78 are cross-sectional. Overall, null associations are predominant. Among studies with non-null associations, negative relationships between healthy food outlets in residential neighbourhoods and childhood obesity is found in seven studies; positive associations between unhealthy food outlets and childhood obesity are found in eight studies, whereas negative associations are found in three studies. Measures of recreational or physical activity facilities around the participants' home are also negatively correlated to childhood obesity in nine out of 15 studies. Results differ by the types of measurement, environmental indicators and geographic units used to characterize obesogenic environments in residential and school neighbourhoods. To improve the study quality and compare reported findings, a reporting standard for spatial epidemiological research should be adopted.

Fast-food restaurant, unhealthy eating, and childhood obesity: A systematic review and meta-analysis

Excessive access to fast-food restaurants (FFRs) in the neighbourhood is thought to be a risk factor for childhood obesity by discouraging healthful dietary behaviours while encouraging the exposure to unhealthful food venues and hence the compensatory intake of unhealthy food option. A literature search was conducted in the PubMed, Web of Science, and Embase for articles published until 1 January 2019 that analysed the association between access to FFRs and weight-related behaviours and outcomes among children aged younger than 18. Sixteen cohort studies and 71 cross-sectional studies conducted in 14 countries were identified. While higher FFR access was not associated with weight-related behaviours (eg, dietary quality score and frequency of food consumption) in most studies, it was commonly associated with more fast-food consumption. Despite that, insignificant results were observed for all meta-analyses conducted by different measures of FFR access in the neighbourhood and weight-related outcomes, although 17 of 39 studies reported positive associations when using overweight/obesity as the outcome. This systematic review and meta-analysis revealed a rather mixed relationship between FFR access and weight-related behaviours/outcomes among children and adolescents.

Grocery store access and childhood obesity: A systematic review and meta-analysis

Grocery store is usually considered to be a healthy food outlet as it provides access to a variety of healthy food, such as fruits and vegetables, which may potentially improve overall dietary quality and protect against obesity. However, findings of the association between grocery store and childhood obesity are controversial. This study aimed to systematically review the evidence on the association between access to grocery stores and childhood obesity. A literature search was conducted in the PubMed, Embase, and Web of Science for articles published before January 1, 2019, using the combinations of three groups of keywords separately for grocery store, children and adolescents, and weight-related behaviours and outcomes. A total of 27 cross-sectional and eight longitudinal studies were identified. Controversial results existed among 24 studies, which examined the association between the access to grocery stores and weight-related outcomes. A null association was observed in almost all meta-analyses conducted by different measures of grocery stores and weight status, except the analysis between presence of grocery stores and overweight, which reached borderline significance. For weight-related behaviours, mixed findings were reported between grocery stores and dietary behaviours, and no significant associations were found for physical activity. This systematic review and meta-analysis suggested that access to grocery stores may have a rather small influence on child weight.

Targeting mailed nicotine patch distribution interventions to rural regions of Canada: protocol for a randomized controlled trial

BACKGROUND

Quitting smoking is the most effective way of reducing the risk of cancer among smokers. One way of helping people stop smoking is to provide them with free Nicotine Replacement Therapy (NRT), such as when NRT is sent to people by postal mail as part of a mass distribution initiative. Our previous research indicated that there may be a substantial impact on increasing quit rates of a mailed NRT intervention in rural areas. The current research seeks to confirm this finding and to understand the social determinants of health driving these anticipated large effects.

METHODS/DESIGN

Telephone numbers will be randomly selected from across rural regions of Canada in order to recruit adult smokers interested in completing a smoking survey and willing to be interviewed again in 6 months. The survey will ask participants about their smoking history, demographic characteristics, and a hypothetical question: would they be interested in receiving nicotine patches if they were provided to them free of charge? Half of the smokers interested in receiving nicotine patches will be selected by chance and offered the NRT package. The other half of smokers will not be offered the nicotine patches. In addition, the municipality where each participant lives will be identified and, once the relevant general population data becomes available, attempts will be made to link participant data to relevant municipal characteristics (e.g., smoking rates, availability of health services). Characteristics of the participants and the municipalities in which they live will be used to explain why the nicotine patch intervention may have a larger impact in some rural regions compared to others.

DISCUSSION

The findings from the proposed RCT are timely and of high relevance as the distribution of nicotine patches has substantial potential to combat the public health problem of cigarette related cancer, other diseases, and premature death from tobacco use. Targeting such tobacco cessation initiatives to rural regions may substantially increase the impact of this intervention, helping to optimize the use of limited prevention resources while aiming to save the maximum number of lives.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov NCT04606797 , October, 27, 2020.

The associations of specific school- and individual-level characteristics with obesity among primary school children in Beijing, China

OBJECTIVE

We aimed to investigate the associations between school-level characteristics and obesity among Chinese primary school children with consideration of individual-level characteristics.

DESIGN

This cross-sectional study was conducted in 2015/2016. School-level characteristics were assessed using an interviewer-administered school questionnaire, and a 'school-based obesity prevention index' was further developed. Individual-level characteristics were collected by self-administered questionnaires. Objectively measured height and weight of students were collected, and obesity status was classified according to the International Obesity Task Force criteria for Asian children. Generalised linear mixed models were used to estimate the associations among the school- and individual-level characteristics and obesity of students.

SETTING

Thirty-seven primary schools from an urban and a rural district of Beijing, China.

PARTICIPANTS

School staffs, 2201 students and their parents.

RESULTS

The school-based obesity prevention index involved the number of health professionals, availability of students' health records, monitoring students' nutrition status, frequency of health education activities, reporting achievements of obesity prevention activities to parents, duration of physical activity during school time and availability of playground equipment. The prevalence of obesity was lower in schools with the higher index value compared with that in schools with the lower index value (OR 0·56; 95 % CI 0·40, 0·79). Some individual-level characteristics were negatively associated with childhood obesity: liking sports, duration of screen time ≤2 h/d, perceived lower eating speed, parental non-overweight/obesity.

CONCLUSIONS

Irrespective of individual-level characteristics, the specific school-level characteristics had a cumulative effect on obesity among Chinese primary school children. Further school-based obesity intervention should consider these characteristics simultaneously.

Built Environment and Childhood Weight Status: A Multi-Level Study Using Population-Based Data in the City of Hannover, Germany

In recent years, built environmental characteristics have been linked to childhood overweight, but the results remain inconsistent across studies. The present study examines associations between several built environmental features and body weight status (BMI) z-score among a large sample of preschool children in the city of Hannover, Germany. Walkability (Index), green space availability, and playground availability related to preschool children's home environments were measured using data from OpenStreetMap (OSM). These built environment characteristics were linked to the data from the 2010-2014 school entry examinations in the Hannover city (n = 22,678), and analysed using multilevel linear regression models to examine associations between the built environment features and the BMI z-score of these children (4-8 years old). No significant associations of built environmental factors on children's BMI were detected, but the effect between green space availability and BMI was modified by the parental educational level. In children with lower compared to higher educated parents, a higher spatial availability of greenspace was significantly associated with reduced body weight. Future research should continue to monitor the disparities in diverse built environment features and how these are related to children's health.

Food environment near schools and body weight-A systematic review of associations by race/ethnicity, gender, grade, and socio-economic factors

Previous research reported modest associations between food environments near schools and adiposity among children overall. The associations within sociodemographic subgroups have not been synthesized. This review assessed the evidence on the associations between food environments near schools and childhood obesity within different demographic and socio-economic subgroups. PubMed and Scopus databases were searched to identify studies published in English between January 1, 1980, and April 25, 2019, examining the presence of fast food outlets, convenience stores, supermarkets, and grocery stores near schools and measures of overweight/obesity by race/ethnicity, gender, grade, and income level. Twelve cross-sectional and two ecological studies were included. Fast food outlets were most commonly examined (n = 12). The associations between fast food outlets near schools and obesity were generally positive among Latino, white, and African American students and across grade levels, although the strengths of evidence varied. The directions of association were mixed among Asian children. Three studies reported generally positive associations between convenience stores and obesity among Latino and African American children and mixed associations among white and Asian children. Longitudinal studies are needed in addition to studies examining underlying mechanisms of the differential influence of food environments near schools within each subgroup.

Exploring Student Food Behaviour in Relation to Food Retail over the Time of Implementing Ontario's School Food and Beverage Policy

Background: Canadian provincial policies, like Ontario’s School Food and Beverage Policy (P/PM 150), increasingly mandate standards for food and beverages offered for sale at school. Given concerns regarding students leaving school to purchase less healthy foods, we examined student behaviours and competitive food retail around schools in a large urban region of Southern Ontario. Methods: Using a geographic information system (GIS), we enumerated food outlets (convenience stores, fast-food restaurants, full-service restaurants) within 500, 1000 and 1500 m of all 389 regional schools spanning years of policy implementation. Consenting grade 6–10 students within 31 randomly selected schools completed a web-based 24-h diet recall (WEB-Q) and questionnaire. Results: Food outlet numbers increased over time (p < 0.01); post-policy, within 1000 m, they averaged 27.31 outlets, with a maximum of 65 fast-food restaurants around one school. Of WEB-Q respondents (n = 2075, mean age = 13.4 ± 1.6 years), those who ate lunch at a restaurant/take-out (n = 84, 4%) consumed significantly more energy (978 vs. 760 kcal), sodium (1556 vs. 1173 mg), and sugar (44.3 vs. 40.1 g). Of elementary and secondary school respondents, 22.1% and 52.4% reported ever eating at fast food outlets during school days. Conclusions: Students have easy access to food retail in school neighbourhoods. The higher energy, sodium and sugar of these options present a health risk.

Chemical and non-chemical stressors affecting childhood obesity: a systematic scoping review

Childhood obesity in the United States has doubled over the last three decades and currently affects 17% of children and adolescents. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-chemical stressors found in a child's environment and how these interactions affect a child's health and well-being. The objectives of this systematic scoping review were to (1) identify potential chemical stressors in the context of non-chemical stressors that impact childhood obesity; and, (2) summarize our observations for chemical and non-chemical stressors in regards to child-specific environments within a community setting. A review was conducted to identify chemical and non-chemical stressors related to childhood obesity for the childhood life stages ranging from prenatal to adolescence. Stressors were identified and grouped into domains: individual behaviors, family/household behaviors, community stressors, and chemical exposures. Stressors were related to the child and the child's everyday environments and used to characterize child health and well-being. This review suggests that the interactions of chemical and non-chemical stressors are important for understanding a child's overall health and well-being. By considering these relationships, the exposure science research community can better design and implement strategies to reduce childhood obesity.

Environments favorable to healthy lifestyles: A systematic review of initiatives in Canada

BACKGROUND

In recent years, a number of initiatives aimed at promoting healthy lifestyles in health-friendly environments have been implemented. The purpose of this review is to synthesize initiatives conducted in Canada and documented in publications for the period 1995-2015 in order to gain a better understanding of their objectives and impacts.

METHODS

A systematic review of Canadian initiatives published over the past 20 years was conducted from multiple databases (i.e., Scopus, SPORTDiscus, PubMed, Academic search complete, Reseausante.com, Cairn, and Erudit). In total, 264 publications were identified and retained for the final analysis based on 5 criteria: (1) publication between 1995 and 2015, (2) online availability, (3) research conducted in Canada, (4) main topic related to environments favorable to healthy lifestyles (EFHL), and (5) publication in French or English.

RESULTS

A sharp increase in the number of studies on EFHL was observed between 2010 and 2015 (57%). Two major lifestyle components-physical activity and nutrition-and 2 environmental aspects-neighborhood and built environment-were the elements most frequently examined regarding adults (48%), young people (34%), and seniors (9%), using quantitative (60%) and qualitative (18%) methods. Furthermore, the analysis reveals a greater focus on the municipal (53%) than the national or provincial levels (31%).

CONCLUSION

This work is a first map of Canadian studies related to EFHL. It clarifies the definition of EFHL and classifies its components. As well, it documents the issues raised, the research methods employed, and the role of stakeholders, while outlining a new research agenda that includes dimensions of EFHL formerly neglected by researchers, namely, political and sociocultural spheres of action.

Sugar Sweetened Beverage Consumption among Primary School Students: Influence of the Schools' Vicinity

The purpose of the research was to explore the associations between the characteristics of schools' vicinity and the risk of sugar sweetened beverage (SSB) consumption in elementary students. Findings exposed an important variation in student's SSB consumption between schools. Schools with a lower socioeconomic status or in a densely built environment tend to have higher proportion of regular SSB drinkers. These characteristics of the school's vicinity partly explained the variation observed between them. We estimated that a student moving to a school with a higher proportion of SSB drinkers may increase his/her chances by 52% of becoming a daily consumer. Important changes in dietary preferences can occur when children are in contact with a new social environment. Findings also support the idea that dietary behaviors among children result from the complex interactions between biological, social, and environmental factors.

Food access and children's BMI in Toronto, Ontario: assessing how the food environment relates to overweight and obesity

OBJECTIVES

The objective was to examine how access to fast food restaurants, less healthy/healthier food outlets and supermarkets relate to measured levels of overweight and obesity among grade 5 and 6 students.

METHODS

Measured height and weight data were obtained to measure BMI. The location and type of food outlet were derived from Toronto Public Health. The density of fast food, less healthy/healthy food outlets and supermarkets within a 1-km walk of the child's home was calculated along with the distance to the closest. Logistic regression models examined the relationship between food access and overweight/obesity.

RESULTS

Lower income residents were more likely to be overweight or obese, as were boys. Living in an area with a higher density of healthy food outlets and in close proximity to a supermarket decreased the odds of being overweight or obese.

CONCLUSIONS

Addressing several limitations in the literature, the findings confirm an association between the food retail environment and body weight. Density of healthy food outlets and distance to the nearest supermarket are important factors to be considered in addressing the childhood obesity pandemic.

A systematic review of the influence of the retail food environment around schools on obesity-related outcomes

The high prevalence of childhood obesity has led to questions about the influence of 'obesogenic' environments on children's health. Public health interventions targeting the retail food environment around schools have been proposed, but it is unclear if they are evidence based. This systematic review investigates associations between food outlets near schools and children's food purchases, consumption and body weight. We conducted a keyword search in 10 databases. Inclusion criteria required papers to be peer reviewed, to measure retailing around schools and to measure obesity-related outcomes among schoolchildren. Thirty papers were included. This review found very little evidence for an effect of the retail food environment surrounding schools on food purchases and consumption, but some evidence of an effect on body weight. Given the general lack of evidence for association with the mediating variables of food purchases and consumption, and the observational nature of the included studies, it is possible that the effect on body weight is a result of residual confounding. Most of the included studies did not consider individual children's journeys through the food environment, suggesting that predominant exposure measures may not account for what individual children actually experience. These findings suggest that future interventions targeting the food environment around schools need careful evaluation.

The proportion of excessive fast-food consumption attributable to the neighbourhood food environment among youth living within 1 km of their school

The study objective was to estimate the proportion of excessive fast-food consumption by youth that is attributable to living and attending school in a neighbourhood with a moderate or high density of fast-food restaurants. This was a cross-sectional study of 6099 Canadian youths (aged 11-15 years) from 255 school neighbourhoods. All participants lived within 1 km of their school. The density of chain fast-food restaurants within a 1-km circular buffer surrounding each school was determined using geographic information systems. Excessive fast-food consumption (≥2 times per week) was assessed by questionnaire. Multilevel logistic regression analysis was used to examine associations. The population attributable risk estimates of excessive fast-food consumption due to neighbourhood exposure to fast-food restaurants were determined based on the prevalence of exposure and the results from the logistic regression. Eight percent of participants were excessive fast-food consumers. After adjusting for sociodemographic factors (i.e., gender, race, and socioeconomic status), it was found that youths from neighbourhoods with a moderate (odds ratio (OR), 1.68; 95% confidence interval (CI), 1.11-2.54) or high (OR 1.70; 95% CI 1.12-2.56) density of chain fast-food restaurants were more likely to be excessive fast-food consumers than were youths from neighbourhoods with no chain fast-food restaurants. Approximately 31% of excessive consumption was attributable to living in neighbourhoods with a moderate or high density of fast-food restaurants. Thus, the fast-food retail environment within which youth live and go to school is an important contributor to their eating behaviours.

A cross-sectional examination of school characteristics associated with overweight and obesity among grade 1 to 4 students

BACKGROUND

Excessive weight gain among youth is an ongoing public health concern. Despite evidence linking both policies and the built environment to adolescent and adult overweight, the association between health policies or the built environment and overweight are often overlooked in research with children. The purpose of this study was to examine if school-based physical activity policies and the built environment surrounding a school are associated with weight status among children.

METHODS

Objectively measured height and weight data were available for 2,331 grade 1 to 4 students (aged 6 to 9 years) attending 30 elementary schools in Ontario, Canada. Student-level data were collected using parent reports and the PLAY-On questionnaire administered to students by study nurses. School-level policy data were collected from school administrators using the Physical Activity Module of the Healthy School Planner tool, and built environment data were provided by the Enhanced Points of Interest data resource. Multi-level logistic regression models were used to examine the school- and student-level characteristics associated with the odds of a student being overweight or obese.

RESULTS

There was significant between-school random variation in the odds of a student being overweight [σ²(μ0) = 0.274(0.106), p < 0.001], but not for being obese [σ²(μ0) = 0.115(0.089)]. If a student attended a school that provided student access to a variety of facilities on and off school grounds during school hours or supported active transportation to and from school, he/she was less likely to overweight than a similar student attending a school without these policies. Characteristics of the built environment were not associated with overweight or obesity among this large cross-sectional sample of children.

CONCLUSIONS

This new evidence suggests that it may be wise to target obesity prevention efforts to schools that do not provide student access to recreation facilities during school hours or schools that do not support active transportation for students. Future research should evaluate if school-based overweight and obesity prevention programming might be improved if interventions selectively targeted the school characteristics that are putting students at the greatest risk.

Are environmental influences on physical activity distinct for urban, suburban, and rural schools? A multilevel study among secondary school students in Ontario, Canada

BACKGROUND

This study examined differences in students' time spent in physical activity (PA) across secondary schools in rural, suburban, and urban environments and identified the environment-level factors associated with these between school differences in students' PA.

METHODS

Multilevel linear regression analyses were used to examine the environment- and student-level characteristics associated with time spent in PA among grades 9 to 12 students attending 76 secondary schools in Ontario, Canada, as part of the SHAPES-Ontario study. This approach was first conducted with the full data set testing for interactions between environment-level factors and school location. Then, school-location specific regression models were run separately.

RESULTS

Statistically significant between-school variation was identified among students attending urban (σ(2) μ0  = 8959.63 [372.46]), suburban (σ(2) μ0  = 8918.75 [186.20]), and rural (σ(2) μ0  = 9403.17 [203.69]) schools, where school-level differences accounted for 4.0%, 2.0%, and 2.1% of the variability in students' time spent in PA, respectively. Students attending an urban or suburban school that provided another room for PA or was located within close proximity to a shopping mall or fast food outlet spent more time in PA.

CONCLUSION

Students' time spent in PA varies by school location and some features of the school environment have a different impact on students' time spent in PA by school location. Developing a better understanding of the environment-level characteristics associated with students' time spent in PA by school location may help public health and planning experts to tailor school programs and policies to the needs of students in different locations.

The number and type of food retailers surrounding schools and their association with lunchtime eating behaviours in students

Background

The primary study objective was to examine whether the presence of food retailers surrounding schools was associated with students’ lunchtime eating behaviours. The secondary objective was to determine whether measures of the food retail environment around schools captured using road network or circular buffers were more strongly related to eating behaviours while at school.

Methods

Grade 9 and 10 students (N=6,971) who participated in the 2009/10 Canadian Health Behaviour in School Aged Children Survey were included in this study. The outcome was determined by students’ self-reports of where they typically ate their lunch during school days. Circular and road network-based buffers were created for a 1 km distance surrounding 158 schools participating in the HBSC. The addresses of fast food restaurants, convenience stores and coffee/donut shops were mapped within the buffers. Multilevel logistic regression was used to determine whether there was a relationship between the presence of food retailers near schools and students regularly eating their lunch at a fast food restaurant, snack-bar or café. The Akaike Information Criteria (AIC) value, a measure of goodness-of-fit, was used to determine the optimal buffer type.

Results

For the 1 km circular buffers, students with 1–2 (OR= 1.10, 95% CI: 0.57-2.11), 3–4 (OR=1.45, 95% CI: 0.75-2.82) and ≥5 nearby food retailers (OR=2.94, 95% CI: 1.71-5.09) were more likely to eat lunch at a food retailer compared to students with no nearby food retailers. The relationships were slightly stronger when assessed via 1 km road network buffers, with a greater likelihood of eating at a food retailer for 1–2 (OR=1.20, 95% CI:0.74-1.95), 3–4 (OR=3.19, 95% CI: 1.66-6.13) and ≥5 nearby food retailers (OR=3.54, 95% CI: 2.08-6.02). Road network buffers appeared to provide a better measure of the food retail environment, as indicated by a lower AIC value (3332 vs. 3346).

Conclusions

There was a strong relationship between the presence of food retailers near schools and students’ lunchtime eating behaviours. Results from the goodness of fit analysis suggests that road network buffers provide a more optimal measure of school neighbourhood food environments relative to circular buffers.

Identification of the appropriate boundary size to use when measuring the food retail environment surrounding schools

This study included 6,971 students in grades 9 and 10 (ages 13 to 16 years) from 158 schools who participated in the 2009/2010 Health Behaviour in School-aged Children Study. Students provided information on where they typically ate lunch. The number of food retailers was obtained for six road network buffer sizes (500, 750, 1,000, 1,500, 2,000, and 5,000 meters) surrounding schools. Associations between the presence of food retailers near schools and students' lunchtime eating behaviours were examined using multilevel logistic regression. Comparisons of model fit statistics indicated that the 1,000 m buffer provided the best fit. At this distance, students with ≥3 food retailers near their schools had a 3.42 times greater relative odds (95% CI: 2.12-5.52) of eating their lunchtime meal at a food retailer compared to students with no nearby food retailers. Students who had ≥2 food retailers within 750 m of their schools had a 2.74 times greater relative odds (95% CI: 1.75-4.29), while those who had ≥1 food retailer within 500 m of their schools had 2.27 times greater relative odds of eating at food retailer (95% CI: 1.46-3.52) compared to those with no nearby food retailers. For distances greater than 1,000 m, no consistent relationships were found.

Does school-based physical activity decrease overweight and obesity in children aged 6-9 years? A two-year non-randomized longitudinal intervention study in the Czech Republic

Background

Globally, efforts aimed at the prevention of childhood obesity have led to the implementation of a range of school-based interventions. This study assessed whether augmenting physical activity (PA) within the school setting resulted in increased daily PA and decreased overweight/obesity levels in 6-9-year-old children.

Methods

Across the first to third primary school years, PA of 84 girls and 92 boys was objectively monitored five times (each for seven successive days) using Yamax pedometer (step counts) and Caltrac accelerometer (activity energy expenditure AEE - kcal/kg per day). Four schools were selected to participate in the research (2 intervention, 2 controls), comprising intervention (43 girls, 45 boys) and control children (41 girls, 47 boys). The study was non-randomized and the intervention schools were selected on the basis of existing PA-conducive environment. Analyses of variance (ANOVA) for repeated measures examined the PA programme and gender effects on the step counts and AEE. Logistic regression (Enter method) determined the obesity and overweight occurrence prospect over the course of implementation of the PA intervention.

Results

There was a significant increase of school-based PA during schooldays in intervention children (from ≈ 1718 to ≈ 3247 steps per day; and from 2.1 to ≈ 3.6 Kcal/Kg per day) in comparison with the control children. Increased school-based PA of intervention children during schooldays contributed to them achieving >10,500 steps and >10.5 Kcal/Kg per school day across the 2 years of the study, and resulted in a stop of the decline in PA levels that is known to be associated with the increasing age of children. Increased school-based PA had also positive impact on leisure time PA of schooldays and on PA at weekends of intervention children. One year after the start of the PA intervention, the odds of being overweight or obese in the intervention children was almost three times lower than that of control children (p < 0.005), and these odds steadily decreased with the duration of the intervention.

Conclusions

The findings suggest that school-based PA (Physical Education lessons, PA during short breaks and longer recesses, PA at after-school nursery) in compatible active environments (child-friendly gym and school playground, corridors with movement and playing around corners and for games) has a vital role in obesity and overweight reduction among younger pupils.

Linking childhood obesity to the built environment: a multi-level analysis of home and school neighbourhood factors associated with body mass index

OBJECTIVES

This study examines environmental factors associated with BMI (body mass index) levels among adolescents with the aim of identifying potential interventions for reducing childhood obesity.

METHODS

Students (n=1,048) aged 10-14 years at 28 schools in London, ON, completed a survey providing information on age, sex, height, weight, home address, etc., which was used to construct age-sex adjusted BMI z-scores. The presence of recreation opportunities, fast-food outlets and convenience stores was assessed using four areal units around each participant's home and school neighbourhood: "circular buffers" encompassing territory within a straight-line distance of 500 m and 1000 m; and "network buffers" of 500 m and 1000 m measured along the street network. School neighbourhoods were also assessed using school-specific "walksheds". Multilevel structural equation modeling techniques were employed to simultaneously test the effects of school-environment (Level 2) and home-environment (Level 1) predictors on BMI z-scores.

RESULTS

Most participants (71%) had a normal BMI, 16.9% were overweight, 7.6% were obese, and 4.6% were considered underweight. Multilevel analyses indicated that built environment characteristics around children's homes and schools had a modest but significant effect on their BMI. The presence of public recreation opportunities within a 500 m network distance of home was associated with lower BMI z-scores (p&lt;0.05), and fast-food outlets within the school walkshed was associated with higher BMI z-scores (p&lt;0.05).

CONCLUSION

Interventions and policies that improve children's access to publicly provided recreation opportunities near home and that mitigate the concentration of fast-food outlets close to schools may be key to promoting healthy lifestyles and reducing childhood obesity.

A multilevel examination of factors of the school environment and time spent in moderate to vigorous physical activity among a sample of secondary school students in grades 9-12 in Ontario, Canada

OBJECTIVE

To examine associations between students' time spent in moderate to vigorous physical activity (MVPA) and the school built environment while also considering features of the schools' social environment and student-level characteristics.

METHODS

Using surveys and GIS measures, multilevel linear regression analysis was applied to examine the environment- and student-level characteristics associated with time spent in MVPA among grade 9-12 students (n = 22,117) attending 76 secondary schools in Ontario, Canada as part of the SHAPES-Ontario study.

RESULTS

Statistically significant between-school random variation in student MVPA was identified [[Formula: see text] = 9,065.22 (250.64)]; school-level differences accounted for 3.0% of the variability in student MVPA. Students attending a school that offered daily physical education or provided an alternate room for physical activity spent more time in MVPA than students attending a school without these resources. Moreover, as land-use mix diversity and walkability of the school neighbourhood increased, students' time spent in MVPA decreased.

CONCLUSION

Developing a better understanding of the environment- and student-level characteristics associated with students' time spent in MVPA is critical for informing school-based physical activity intervention programmes and policies.