Differential associations between the food environment near schools and childhood overweight across race/ethnicity, gender, and grade

"Competitive" food and beverage policies and weight status: A systematic review of the evidence among sociodemographic subgroups

Prior studies identified variable associations between competitive food and beverage policies (CF&B) and youth obesity, potentially due to differences across population subgroups. This review summarizes the evidence on associations between CF&B policies and childhood obesity within gender, grade level/ age, race/ethnicity, and/or socioeconomic levels. PubMed, EMBASE, CINAHL, and ERIC database searches identified studies published in English in Canada and the United States between January 1, 2000, and February 28, 2022. Of the 18 selected studies, six were cross-sectional, two correlational, nine were before/after designs, and one study utilized both a cross-sectional and pre-post design. Twelve studies reported findings stratified by a single sociodemographic factor, with grade level/age as the most frequently reported. Although the evidence varied, greater consistency in direction of associations and strengths of evidence were seen among middle school students. Six studies reported findings jointly by multiple sociodemographic subgroups with evidence suggesting CF&B associations with slower rate of increase or plateaus or declines in obesity among multiple subgroups, though the strengths of evidence varied. Over the past two decades, there have been relatively limited subgroup analyses on studies about CF&B policies and childhood obesity. Studies are needed with stronger designs and analyses disaggregated, particularly by race/ethnicities and socioeconomic factors, across places and time.

Food Environment around Schools: A Systematic Scope Review

The present systematic scope review intended to compile state-of-the-art information about the food environment around schools, exploring the main methods used to describe the food environment around schools as well as the possible effects that this environment can promote on the health of children and adolescents. The preferred reporting items for systematic reviews and meta-analyses-extension for scoping reviews (PRISMA-ScR) checklist and guidelines were followed to ensure a robust and repeatable methodological process. A systematic search was performed in the following electronic databases: MEDLINE, Embase, Science Direct, Web of Science, LILACS, and Scopus, as well as in related articles, a manual search of reference lists and gray literature. Forty-six studies were selected. There was no standardization regarding distances from food establishments to schools, methods of analysis, and software used. The food environment around the schools was characterized by the wide availability of food establishments, especially fast food, convenience stores, supermarkets, and grocery stores known for offering a wide variety of unhealthy foods. Regarding the correlations with the health of children and adolescents, the evidence points to possible interferences of the food environment known as obesogenic, but it cannot be related only to the school environment since most of the acquisition and consumption of food usually happens around family homes. Conducting standardized and comprehensive studies evaluating food choices in the school environment and their interrelationships is very important to ensure children's food and nutrition security and minimize negative health outcomes in the medium and long term.

Characterizing food environments near schools in California: A latent class approach simultaneously using multiple food outlet types and two spatial scales

It is challenging to evaluate associations between the food environment near schools with either prevalence of childhood obesity or with socioeconomic characteristics of schools. This is because the food environment has many dimensions, including its spatial distribution. We used latent class analysis to classify public schools in urban, suburban, and rural areas in California into food environment classes based on the availability and spatial distribution of multiple types of unhealthy food outlets nearby. All urban schools had at least one unhealthy food outlet nearby, compared to seventy-two percent of schools in rural areas did. Food environment classes varied in the quantity of available food outlets, the relative mix of food outlet types, and the outlets' spatial distribution near schools. Regardless of urbanicity, schools in low-income neighborhoods had greater exposure to unhealthy food outlets. The direction of associations between food environment classes and school size, type, and race/ethnic composition depends on the level of urbanicity of the school locations. Urban schools attended primarily by African American and Asian children are more likely to have greater exposures to unhealthy food outlets. In urban and rural but not suburban areas, schools attended primarily by Latino students had more outlets offering unhealthy foods or beverages nearby. In suburban areas, differences in the spatial distribution of food outlets indicates that food outlets are more likely to cluster near K-12 schools and high schools compared to elementary schools. Intervention design and future research need to consider that the associations between food environment exposures and school characteristics differ by urbanicity.

Food Products with the Child-Targeted Packaging in Food Stores around Primary Schools in Tehran, Iran

The local retail food environment around schools can have an important role in encouraging children to low-quality food choices; and may act as a potential risk factor in their diet. Thus, evaluating the food environment is essential for adopting policies and programs that support healthy nutrition in children. This study aimed to investigate the frequency and nutritional characteristics of packaged processed/ultra-processed food and beverage products with child-oriented marketing attributes in food stores around primary schools in Tehran, Iran. This cross-sectional study was conducted on 239 food stores located within a 500-meter buffer around 64 primary schools in Tehran province. The presence of marketing strategies directed at children and nutrition information from traffic light labels of packaged foods available in these stores were extracted. Data were analyzed overall and separately for the subset of foods placed on front shelves at the entrance of stores. Among 445 discrete food products marketed to children via their packaging, 198 (44.49%) were placed on shelves in front of the stores entrance. Potato chips and bulky cereals group had the highest energy density (507.15 ± 44.05 Kcal/100gr). Due to the color code of traffic light labels, 100% of fruit juices had high levels of sugar. Of potato chips and bulky cereals, 89.38% were assigned a red color traffic light for total fat levels. Moreover, 62.50% of processed fruit and vegetables contained high levels of salt. The level of trans-fatty acids were not high in any of the food products. The high amount of sugar, salt, and fat in a remarkable proportion of food products marketed to children can be considered a risk factor for children's health. Initiation and implementation of appropriate policies to control the food environment around schools in Iran is recommended.

Perceived Availability of Healthy and Unhealthy Foods in the Community, Work, and Higher Education Settings across Five Countries: Findings from the International Food Policy Study 2018

BACKGROUND

Food environments play a key role in dietary behavior and vary due to different contexts, regulations, and policies.

OBJECTIVES

This study aimed to characterize the perceived availability of healthy and unhealthy foods in 3 different settings in 5 countries.

METHODS

We analyzed data from the 2018 International Food Policy Study, a cross-sectional survey of adults (18-100 y, n = 22,824) from Australia, Canada, Mexico, the United Kingdom (UK), and the USA. Perceived availability of unhealthy (junk food and sugary drinks) and healthy foods (fruit or vegetables, healthy snacks, and water) in the community, workplace, and university settings were measured (i.e. not available, available for purchase, or available for free). Differences in perceived availability across countries were tested using adjusted multinomial logistic regression models.

RESULTS

Across countries, unhealthy foods were perceived as highly available in all settings; in university and work settings unhealthy foods were perceived as more available than healthy foods. Australia and Canada had the highest perceived availability of unhealthy foods (range 87.5-90.6% between categories), and the UK had the highest perceived availability of fruits and vegetables for purchase (89.3%) in the community. In university and work settings, Mexico had the highest perceived availability for purchase of unhealthy foods (range 69.9-84.9%). The USA and the UK had the highest perceived availability of fruits and vegetables for purchase (65.3-66.3%) or for free (21.2-22.8%) in the university. In the workplace, the UK had high perceived availability of fruits and vegetables for purchase (40.2%) or for free (18.5%), and the USA had the highest perceived availability of junk food for free (17.3%).

CONCLUSIONS

Across countries, unhealthy foods were perceived as highly available in all settings. Variability between countries may reflect differences in policies and regulations. Results underscore the need for the continuation and improvement of policy efforts to generate healthier food environments.

Longitudinal geo-referenced field evidence for the heightened BMI responsiveness of obese women to price discounts on carbonated soft drinks

There is increasing interest in the effect that food environments may have on obesity, particularly through mechanisms related to the marketing and consumption of calorie-dense, nutrient-poor foods and sugary beverages. Price promotions, such as temporary price discounts, have been particularly effective in the marketing of carbonated soft drinks (CSDs) among consumers. Research has also suggested that the purchasing behavior of consumer groups may be differentially sensitive to price discounts on CSDs, with obese women particularly sensitive. In addition, the intensity of price discount in a person's food environment may also vary across geography and over time. This study examines whether the weight change of obese women, compared to overweight or normal BMI women, is more sensitive to the intensity of price discounts on CSDs in the food environment. This study used longitudinal survey data from 1622 women in the Montreal Neighborhood Networks and Health Aging (MoNNET-HA) Panel. Women were asked to report their height and weight in 2008, 2010 and 2013 in order to calculate women's BMI in 2008 and their change of weight between 2008 and 2013. Women's exposure to an unhealthy food environment was based on the frequency in which their neighborhood food stores placed price discounts on CSDs in 2008. The price discount frequency on CSDs within women's neighborhoods was calculated from Nielsen point-of sales transaction data in 2008 and geocoded to participant's forward sortation area. The prevalence of obesity and overweight among MoNNET-HA female participants was 18.3% in 2008, 19.9% in 2010 and 20.7% in 2013 respectively. Results showed that among obese women, exposure to unhealthy food environments was associated with a 3.25 kilogram (SE = 1.35, p-value = 0.02) weight gain over the five-year study period. Exposure to price discounts on CSDs may disproportionately affect and reinforce weight gain in women who are already obese.

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.

Association between access to convenience stores and childhood obesity: A systematic review

Childhood obesity increases the risk of adulthood obesity and is associated with other adverse health outcomes later in life. It may be influenced by environmental characteristics of neighborhoods where children live, particularly dietary supply-related environmental factors. This study aimed to systematically review the evidence on the association between access to convenience stores and childhood obesity. We searched and filtered relevant literature in PubMed, Embase, Web of Science, and Cochrane Library published before 1 January 2019. Data on the basic characteristics of studies, measures of access to convenience stores, and associations of convenience stores with weight-related behaviors and outcomes were extracted from 41 included studies. In general, the density of and proximity to convenience stores in children's residential and school neighborhoods were positively associated with unhealthy eating behaviors. However, their associations with children's weight status varied significantly by regions. The association between convenience store access and children's weight status was found to be negative in Canada, rather mixed in the United States and the United Kingdom, and not significant in East Asia. We suggest future research to clearly define the convenience store, better measure the access to convenience store, and also measure children's journey and food purchasing and consumption behaviors, to explain pathways from convenience store access to childhood obesity for designing effective interventions and policies.

Relationship between retail food outlets near public schools and adolescent obesity in New York City

Using objectively-measured height and weight data from academic years 2009-2013 (n = 1,114,010 student-year observations), we estimated the association between the food outlet in closest proximity to schools and the likelihood of obesity among New York City public high school students. Obesity risk was higher for students with a corner store as the nearest option to schools, regardless of whether other food outlet types were located within a quarter mile or a half mile of schools (i.e., benchmarks for zoning policies). Policymakers may want to consider introducing healthier food options near schools, in conjunction with programs to support changes within corner stores.

The neighborhood food environment modifies the effect of the 2009 WIC food package change on childhood obesity in Los Angeles County, California

Background

Food packages provided by the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) were revised in 2009 to better align them with the Dietary Guidelines for Americans. This study was conducted to evaluate whether the effect of the food package change on childhood obesity varied by the food environment in the neighborhoods where WIC-participating children live.

Methods

Administrative data from participating children in Los Angeles County, California (2003–2016) were merged with geocoded food vendor information by neighborhood of residence. Obesity risk at age 4 was compared between children receiving old (2003–2009) and new (2010–2016) WIC food packages using sex-stratified Poisson regression models, with interaction terms between WIC package and neighborhood density (number per square mile) of healthy and unhealthy food outlets.

Results

The new food package was associated with a significant decrease in obesity risk. Among boys, the new food package was associated with 8 to 18% lower obesity risk at all healthy and unhealthy food outlet densities, and the association was not modified by neighborhood food outlet density. Among girls, the association of the new food package with obesity risk was protective in neighborhoods with high healthy and low unhealthy food outlet densities, and adverse in neighborhoods with high unhealthy and low healthy food outlet densities. The effect of the new food package among girls was modified by unhealthy food outlet density, with significantly smaller (p-value = 0.004) decreases in obesity risk observed in neighborhoods with higher unhealthy food outlet density.

Conclusions

The impact of the food package change was modified by the neighborhood food environment among girls only. Future policy changes should incorporate consideration of ways to mitigate potentially inequitable geographic distribution of the health benefits of policy changes.

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.

The emerging landscape of health research based on biobanks linked to electronic health records: Existing resources, statistical challenges, and potential opportunities

Biobanks linked to electronic health records provide rich resources for health-related research. With improvements in administrative and informatics infrastructure, the availability and utility of data from biobanks have dramatically increased. In this paper, we first aim to characterize the current landscape of available biobanks and to describe specific biobanks, including their place of origin, size, and data types. The development and accessibility of large-scale biorepositories provide the opportunity to accelerate agnostic searches, expedite discoveries, and conduct hypothesis-generating studies of disease-treatment, disease-exposure, and disease-gene associations. Rather than designing and implementing a single study focused on a few targeted hypotheses, researchers can potentially use biobanks' existing resources to answer an expanded selection of exploratory questions as quickly as they can analyze them. However, there are many obvious and subtle challenges with the design and analysis of biobank-based studies. Our second aim is to discuss statistical issues related to biobank research such as study design, sampling strategy, phenotype identification, and missing data. We focus our discussion on biobanks that are linked to electronic health records. Some of the analytic issues are illustrated using data from the Michigan Genomics Initiative and UK Biobank, two biobanks with two different recruitment mechanisms. We summarize the current body of literature for addressing these challenges and discuss some standing open problems. This work complements and extends recent reviews about biobank-based research and serves as a resource catalog with analytical and practical guidance for statisticians, epidemiologists, and other medical researchers pursuing research using biobanks.

Association between convenience stores near schools and obesity among school-aged children in Beijing, China

Background

Food environments have rapidly changed over the past years in China and children have more access to unhealthy food in convenience stores near schools. Since the studies on the association between convenience stores near schools and obesity had inconsistent results and no similar study in China, we conducted a study on the association in Beijing of China, which will provide scientific evidence for the intervention of childhood obesity.

Methods

The study included 2201 students at grade 4 of 37 primary schools in Dongcheng or Miyun district of Beijing. The food environment data was acquired from AMAP, the free web-based geospatial service provider. The numbers of convenience stores were captured within the 800-m network buffer near schools using Geographic Information System. The weight and height of each student were measured by trained health professionals. Students’ dietary and physical behaviors and other information associated with obesity were collected with questionnaires for students and their parents. The generalized linear mixed model (GLMM) was used to analyze the data.

Results

The average age of the students was 10.2 years (Standard Deviation (SD) = 0.33). The prevalence of obesity in students was 14.9%. The median number of convenience stores within the 800-m network buffer near schools was 24 in two districts. The number of convenience stores near each school varied from 5 to 67 (median: 25) in Dongcheng district and from 1 to 57 (median: 22) in Miyun district. After adjusting for the confounding factors at the family and individual levels, the association between convenience stores and childhood obesity was statistically significant. Additional ten convenience stores near schools were associated with an increased risk of obesity (Odds Ratio (OR) = 1.13, 95% confidence interval (CI): 1.03,1.24, P = 0.011). Compared with less than 24 convenience stores near schools, the students with more than or equal to 24 convenience stores near schools had an increased risk of obesity (OR = 1.49, 95% CI: 1.09, 2.03, P = 0.013).

Conclusion

The students with more convenience stores near their schools had an increased risk of obesity. The findings provided evidence for developing public health policy to restrict the number of convenience stores near schools to prevent and control childhood obesity.

Changes in Fast Food Outlet Availability Near Schools: Unequal Patterns by Income, Race/Ethnicity, and Urbanicity

INTRODUCTION

Previous research has observed income or racial/ethnic inequalities in fast food restaurant availability near schools. The purpose of this study was to investigate changes in fast food restaurant availability near schools between 2000 and 2010 by school neighborhood income, race/ethnicity, and urbanicity.

METHODS

Using data from 7,466 California public schools, negative binomial regression models estimated the relative ratios to evaluate the income gradient in fast food restaurant availability, examine differences in the income gradient in fast food restaurant availability between 2000 and 2010, and investigate if fast food restaurant availability changed in 2010 versus 2000, stratified by race/ethnicity and urbanicity. The analyses were conducted in 2018 and early 2019.

RESULTS

In urban areas, there was a negative school neighborhood income gradient in fast food restaurant availability in both 2000 and 2010, and across all race/ethnic groups, except majority African American schools. The income gradient in fast food restaurant availability was steeper in 2010 relative to 2000 among Latino majority urban schools. Fast food restaurant availability increased in 2010 relative to 2000 among majority African American, majority Latino, and majority Asian schools in the least affluent neighborhoods. Among majority white schools in similar neighborhoods the availability of fast food restaurants did not change but declined in the most affluent school neighborhoods. In nonurban areas, the income patterns in fast food restaurant availability were less clear, and fast food restaurant availability increased among majority white and Latino schools within the middle neighborhood income tertile.

CONCLUSIONS

These findings suggest the need for future interventions to target schools in low-income urban neighborhoods. Additionally, reducing child health disparities and improving health for all children requires monitoring changes in the food environment near schools.

Describing Food and Beverage Restaurants: Creating A Reliable Coding Tool

Objective

To develop an informed, reliable data collection tool to code restaurants found within the youth food environment.

Methods

Registered Dietitians were surveyed and academic literature review was reviewed to determine health centric food environment features. Features were incorporated into an electronic data collection tool. Inter-rater reliability was tested across coders of varying nutrition training on all restaurants located within a half-mile of three high schools.

Results

Sixteen restaurant food environment codes were generated. Data collection had a mean inter-rater reliability of 90.7% agreement (range=81.3-100%), suggesting that regardless of nutrition training, the restaurant food environment can be reliability coded.

Conclusions

Academic and public health professionals can use this tool to collect reliable, informed local restaurant food environment data.

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.

Measures of the food environment: A systematic review of the field, 2007-2015

BACKGROUND

Many studies have examined the relationship between the food environment and health-related outcomes, but fewer consider the integrity of measures used to assess the food environment. The present review builds on and makes comparisons with a previous review examining food environment measures and expands the previous review to include a more in depth examination of reliability and validity of measures and study designs employed.

METHODS

We conducted a systematic review of studies measuring the food environment published between 2007 and 2015. We identified these articles through: PubMed, Embase, Web of Science, PsycINFO, and Global Health databases; tables of contents of relevant journals; and the National Cancer Institute's Measures of the Food Environment website. This search yielded 11,928 citations. We retained and abstracted data from 432 studies.

RESULTS

The most common methodology used to study the food environment was geographic analysis (65% of articles) and the domination of this methodology has persisted since the last review. Only 25.9% of studies in this review reported the reliability of measures and 28.2% reported validity, but this was an improvement as compared to the earlier review. Very few of the studies reported construct validity. Studies reporting measures of the school or worksite environment have decreased since the previous review. Only 13.9% of the studies used a longitudinal design.

CONCLUSIONS

To strengthen research examining the relationship between the food environment and population health, there is a need for robust and psychometrically-sound measures and more sophisticated study designs.

Association between junk food consumption and fast-food outlet access near school among Quebec secondary-school children: findings from the Quebec Health Survey of High School Students (QHSHSS) 2010–11

Objective

We investigated the association between junk food consumption at lunchtime (JCL) and fast-food outlet access near school among secondary-school children in Quebec.

Design

A geographic information system database was used to characterize the food environment around a sub-sample of 374 public schools in which 26 655 students were enrolled. The outcome variable was JCL during the previous week, dichotomized into low JCL (none or once)v. high JCL (twice or more). Access to fast-food outlets near school was assessed using an existing database of fast-food outlets in Quebec. Covariates included student (age, sex and self-rated perceived health), family (familial status and parental education) and school (urban/rural status and deprivation) variables. Hierarchical logistic regression models were employed for analyses using PROC GLIMMIX of SAS version 9.3.

Setting

Province of Quebec, Canada.

Subjects

We used data from the Quebec Health Survey of High School Students (QHSHSS) 2010–11, a survey of secondary-school Quebec students.

Results

Exposure to two or more fast-food outlets within a radius of 750 m around schools was associated with a higher likelihood of excess JCL (OR=1·50; 95 % CI 1·28, 1·75), controlling for the characteristics of the students, their families and their schools.

Conclusions

The food environment surrounding schools can constitute a target for interventions to improve food choices among secondary-school children living in the province of Quebec. Transforming environments around schools to promote healthy eating includes modifying zoning regulations that restrict access to fast-food outlets around schools.

Active school transport and fast food intake: Are there racial and ethnic differences?

OBJECTIVES

To investigate whether active school transport was associated with fast food consumption, and to examine differences across racial/ethnic groups.

METHODS

Adolescent data (n=3194) from the 2009 California Health Interview Survey were analyzed with logistic regression models to examine the association between active school transport (AST) and fast food intake across racial/ethnic groups.

RESULTS

In the overall sample, AST during 1-2days in the past week was associated with greater likelihood of fast food intake (OR: 1.58; 95% CI: 1.03-2.43), compared with zero days of AST, controlling for demographic and other factors. The association between AST and fast food intake differed significantly by race/ethnicity (p<0.01). Among Latino adolescents, greater frequency of AST was significantly associated with greater likelihood of fast food intake (1-2days OR, 2.37, 95%CI: 1.05-5.35; 3-4days OR, 2.78, 95% CI: 1.04-7.43; 5days OR, 2.20, 95%CI: 1.23-3.93). Among White and Asian adolescents, there was a curvilinear pattern: relative to adolescents who reported zero days of AST, those who did AST 1-2days/week had greater likelihood of fast food intake, but AST of 3-4days and 5days/week was associated respectively, with higher and lower likelihood of fast food intake among both groups.

CONCLUSIONS

AST appears to be a risk factor for fast food intake, and may expose some ethnic groups more than others to increased opportunity to purchase and consume fast food. Programs and policies to promote AST among adolescents should incorporate efforts to encourage healthy eating and discourage concentration of fast food outlets near schools.

The Toxic Food Environment Around Elementary Schools and Childhood Obesity in Mexican Cities

INTRODUCTION

The childhood obesity epidemic is a global concern. There is limited evidence in Mexico linking the local food environment to obesity. The purpose of this study is to describe the links between the local food environment around elementary schools and schoolchildren's BMI in two Mexican cities.

METHODS

Cross-sectional surveys were conducted in 60 elementary schools in two Mexican cities (i.e., Cuernavaca and Guadalajara) in 2012-2013. Anthropometric measurements on schoolchildren were collected, as well as environmental direct audits and observations in a 100-m buffer around schools. Children's BMI was evaluated according to WHO-recommended procedures. In BMI models, the explanatory variable was the number of retail food sources. These models were adjusted for child's characteristics, schools' socioeconomic background, compliance with federal guidelines concerning unhealthy foods within schools' facilities, and corresponding city. Analysis was conducted in 2014.

RESULTS

The number of mobile food vendors was higher around public schools than outside private schools (p<0.05). Linear regression procedures showed a significant positive statistical association between children's BMI and the number of mobile food vendors around schools. Schoolchildren from the highest tertile of mobile food vendors showed 6.8% higher BMI units than those from the lowest tertile. Children attending schools within the highest tertile of food stores also had 4.7% higher BMI units than children from schools in the lowest tertile.

CONCLUSIONS

Health policy in Mexico should target the obesogenic environment surrounding elementary schools, where children may be more exposed to unhealthy foods.

Measuring the food environment and its effects on obesity in the United States: a systematic review of methods and results

We identified fifty-one peer-reviewed studies that geospatially analyzed the relationship between the community nutrition environment (CNE) and obesity. Eighty percent of studies found at least one significant association between the CNE and obesity. However we calculated the proportion of studies that found at least one significant association between the CNE and obesity in the expected direction for each food store type and measurement technique, and the proportion across the different store types and measurement techniques was just 32%. Different methods for classifying, locating, and analyzing food stores produced mixed results and challenged direct study level comparison.

Distributed Lag Models: Examining Associations Between the Built Environment and Health

Built environment factors constrain individual level behaviors and choices, and thus are receiving increasing attention to assess their influence on health. Traditional regression methods have been widely used to examine associations between built environment measures and health outcomes, where a fixed, prespecified spatial scale (e.g., 1 mile buffer) is used to construct environment measures. However, the spatial scale for these associations remains largely unknown and misspecifying it introduces bias. We propose the use of distributed lag models (DLMs) to describe the association between built environment features and health as a function of distance from the locations of interest and circumvent a-priori selection of a spatial scale. Based on simulation studies, we demonstrate that traditional regression models produce associations biased away from the null when there is spatial correlation among the built environment features. Inference based on DLMs is robust under a range of scenarios of the built environment. We use this innovative application of DLMs to examine the association between the availability of convenience stores near California public schools, which may affect children's dietary choices both through direct access to junk food and exposure to advertisement, and children's body mass index z scores.

Associations between Food Outlets around Schools and BMI among Primary Students in England: A Cross-Classified Multi-Level Analysis

INTRODUCTION

Researchers and policy-makers are interested in the influence that food retailing around schools may have on child obesity risk. Most previous research comes from North America, uses data aggregated at the school-level and focuses on associations between fast food outlets and school obesity rates. This study examines associations between food retailing and BMI among a large sample of primary school students in Berkshire, England. By controlling for individual, school and home characteristics and stratifying results across the primary school years, we aimed to identify if the food environment around schools had an effect on BMI, independent of socio-economic variables.

METHODS

We measured the densities of fast food outlets and food stores found within schoolchildren's home and school environments using Geographic Information Systems (GIS) and data from local councils. We linked these data to measures from the 2010/11 National Child Measurement Programme and used a cross-classified multi-level approach to examine associations between food retailing and BMI z-scores. Analyses were stratified among Reception (aged 4-5) and Year 6 (aged 10-11) students to measure associations across the primary school years.

RESULTS

Our multilevel model had three levels to account for individual (n = 16,956), home neighbourhood (n = 664) and school (n = 268) factors. After controlling for confounders, there were no significant associations between retailing near schools and student BMI, but significant positive associations between fast food outlets in home neighbourhood and BMI z-scores. Year 6 students living in areas with the highest density of fast food outlets had an average BMI z-score that was 0.12 (95% CI: 0.04, 0.20) higher than those living in areas with none.

DISCUSSION

We found little evidence to suggest that food retailing around schools influences student BMI. There is some evidence to suggest that fast food outlet densities in a child's home neighbourhood may have an effect on BMI, particularly among girls, but more research is needed to inform effective policies targeting the effects of the retail environment on child obesity.

Associations between food environment around schools and professionally measured weight status for middle and high school students

BACKGROUND

Obesity rates among school-age children remain high. Access to energy-dense foods at home, in schools, in stores, and restaurants around homes and schools is of concern. Research on the relationship between food environment around schools and students' weight status is inconclusive. This study examines the association between weight status of middle and high school students and proximity to a comprehensive set of food outlets around schools.

METHODS

Deidentified nurse-measured heights and weights data were obtained for 12,954 middle and high school students attending 33 public schools in four low-income communities in New Jersey. Geocoded locations of supermarkets, convenience stores, small grocery stores, and limited-service restaurants were obtained from commercial sources. Random-effect regression models with robust standard errors were developed to adjust for unequal variances across schools and clustering of students within schools.

RESULTS

Proximity to small grocery stores that offered some healthy options (e.g., five fruits, five vegetables, and low-fat/skim milk) and supermarkets was associated with healthier student weight status. Having a small grocery store within 0.25 mile of school and an additional such store within that radius was associated with a lower BMI z-score (p<0.05). An additional supermarket within 0.25 mile of schools was associated with a lower probability of being overweight/obese (p<0.05).

CONCLUSIONS

Improving access to healthy food outlets, such as small stores, that offer healthy food options and supermarkets around middle and high schools is a potential strategy for improving weight outcomes among students.

Food Away from Home and Childhood Obesity

Childhood obesity is associated with a number of serious health risks that can persist into adulthood. While trends in food away from home and fast-food consumption have paralleled trends in childhood obesity, it is important to identify whether this is a causal relationship. This paper reviews recent literature in this area to summarize if there is a consensus in research findings. We group the literature into two areas - consumption of and access to food away from home (FAFH). While no consensus findings have been reached in either area, the evidence of an association between FAFH consumption and childhood obesity has gained strength. Further, there is evidence that FAFH meals add calories to children's diets. The literature on the role of FAFH access and childhood obesity has continued producing mixed results.

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.

Hierarchical multiple informants models: examining food environment contributions to the childhood obesity epidemic

Methods for multiple informants help to estimate the marginal effect of each multiple source predictor and formally compare the strength of their association with an outcome. We extend multiple informant methods to the case of hierarchical data structures to account for within cluster correlation. We apply the proposed method to examine the relationship between features of the food environment near schools and children's body mass index z-scores (BMIz). Specifically, we compare the associations between two different features of the food environment (fast food restaurants and convenience stores) with BMIz and investigate how the association between the number of fast food restaurants or convenience stores and child's BMIz varies across distance from a school. The newly developed methodology enhances the types of research questions that can be asked by investigators studying effects of environment on childhood obesity and can be applied to other fields.

Business list vs ground observation for measuring a food environment: saving time or waste of time (or worse)?

In food-environment research, an alternative to resource-intensive direct observation on the ground has been the use of commercial business lists. We sought to determine how well a frequently used commercial business list measures a dense urban food environment like the Bronx, NY. On 155 Bronx street segments, investigators compared two different levels for matches between the business list and direct ground observation: lenient (by business type) and strict (by business name). For each level of matching, researchers calculated sensitivities and positive predictive values (PPVs) for the business list overall and by broad business categories: General Grocers (eg, supermarkets), Specialty Food Stores (eg, produce markets), Restaurants, and Businesses Not Primarily Selling Food (eg, newsstands). Even after cleaning the business list (eg, for cases of multiple listings at a single location), and allowing for inexactness in listed street addresses and spellings of business names, the overall performance of the business list was poor. For strict matches, the business list had an overall sensitivity of 39.3% and PPV of 45.5%. Sensitivities and PPVs by broad business categories were not meaningfully different from overall values, although sensitivity for General Grocers and PPV for Specialty Food Stores were particularly low: 26.2% and 32%, respectively. For lenient matches, sensitivities and PPVs were somewhat higher but still poor: 52.4% to 60% and 60% to 75%, respectively. The business list is inadequate to measure the actual food environment in the Bronx. If results represent performance in other settings, findings from prior studies linking food environments to diet and diet-related health outcomes using such business lists are in question, and future studies of this type should avoid relying solely on such business lists.