Estimating the effect of latent time-varying count exposures using multiple lists.

A major challenge in longitudinal built-environment health studies is the accuracy of commercial business databases that are used to characterize dynamic food environments. Different databases often provide conflicting exposure measures on the same subject due to different source credibilities. As on-site verification is not feasible for historical data, we suggest combining multiple databases to correct the bias in health effect estimates due to measurement error in any 1 datasource. We propose a joint model for the time-varying health outcomes, observed count exposures, and latent true count exposures. Our model estimates the time-specific quality of sources and incorporates time dependence of true count exposure by Poisson integer-valued first-order autoregressive process. We take a Bayesian nonparametric approach to flexibly account for location-specific exposures. By resolving the discordance between different databases, our method reduces the bias in the longitudinal health effect of the true exposures. Our method is demonstrated with childhood obesity data in California public schools with respect to convenience store exposures in school neighborhoods from 2001 to 2008.

Temporal Patterns in Fruit and Vegetable Intake Among Racially and Ethnically Diverse Children and Adolescents in California.

Introduction: Childhood dietary behaviors, including fruit and vegetable intake, are associated with adult health. Most children do not meet daily recommended servings of fruits and vegetables. Less is known about temporal patterns in fruit and vegetable consumption or if they vary by race and ethnicity. We investigated temporal patterns in fruit and vegetable intake among California school-age children and adolescents overall and by race and ethnicity. Methods: We used 2-year cross-sectional datasets from the child and adolescent samples in the California Health Interview Surveys from 2011-2012 through 2019-2020 and modified Poisson regression models to estimate the likelihood of consuming 5 or more servings of fruits and vegetables in 2013-2016 and 2017-2020 compared with 2011-2012. Models controlled for age, race and ethnicity, gender, citizenship status, family income, and adult education and tested for differences by race and ethnicity. The samples included 16,125 children aged 5 to 11 years and 9,672 adolescents aged 12 to 17 years. Results: Overall, 29.3% of children and 25.9% of adolescents reported intake of 5 or more fruits and vegetables per day. Among children, adjusted prevalence ratios (PR) of fruit and vegetable intake were higher in 2013-2016 (PR,1.25; 95% CI, 1.11-1.42) and 2017-2020 (PR,1.13; 95% CI, 0.99-1.30) compared with 2011-2012. Among adolescents, the adjusted prevalence did not differ significantly over time. We found no evidence of differential associations by race and ethnicity for children and adolescents. Conclusion: We found favorable temporal changes in fruit and vegetable consumption among children, but not among adolescents. Monitoring temporal patterns in fruit and vegetable intake remains critical for planning population-level interventions to increase consumption.

Split and combine simulation extrapolation algorithm to correct geocoding coarsening of built environment exposures.

A major challenge in studies relating built environment features to health is measurement error in exposure due to geocoding errors. Faulty geocodes in built environment data introduce errors to exposure assessments that may induce bias in the corresponding health effect estimates. In this study, we examine the distribution of the measurement error in measures constructed from point-referenced exposures, quantify the extent of bias in exposure effect estimates due to geocode coarsening, and extend the simulation extrapolation (SIMEX) method to correct the bias. The motivating example focuses on the association between children's body mass index and exposure to the junk food environment, represented by the number of junk food outlets within a buffer area near their schools. We show, algebraically and through simulation studies, that coarsening of food outlet coordinates results in exposure measurement errors that have heterogeneous variance and nonzero mean, and that the resulting bias in the health effect can be away from the null. The proposed SC-SIMEX procedure accommodates the nonstandard measurement error distribution, without requiring external data, and provides the best bias correction compared to other SIMEX approaches.

California and federal school nutrition policies and obesity among children of Pacific Islander, American Indian/Alaska Native, and Filipino origins: Interrupted time series analysis.

BACKGROUND: Obesity prevalence remains high among children of Pacific Islander (PI) origin, Filipino (FI), and American Indian/Alaska Native (AIAN) origins in the United States. While school nutrition policies may help prevent and reduce childhood obesity, their influences specifically among PI, FI, and AIAN children remain understudied. We evaluated the association of the California (CA) state school nutrition policies for competitive food and beverages and the federal policy for school meals (Healthy, Hunger-Free Kids Act of 2010 (HHFKA 2010)) with overweight/obesity among PI, FI, and AIAN students. METHODS AND FINDINGS: We used an interrupted time series (ITS) design with FitnessGram data from 2002 to 2016 for PI (78,841), FI (328,667), AIAN (97,129), and White (3,309,982) students in fifth and seventh grades who attended CA public schools. Multilevel logistic regression models estimated the associations of the CA school nutrition policies (in effect beginning in academic year 2004 to 2005) and HHFKA 2010 (from academic year 2012 to 2013) with overweight/obesity prevalence (above the 85 percentile of the age- and sex-specific body mass index (BMI) distribution). The models were constructed separately for each grade and sex combination and adjusted for school district-, school-, and student-level characteristics such as percentage of students eligible for free and reduced price meals, neighborhood income and education levels, and age. Across the study period, the crude prevalence of overweight/obesity was higher among PI (39.5% to 52.5%), FI (32.9% to 36.7%), and AIAN (37.7% to 45.6%) children, compared to White (26.8% to 30.2%) students. The results generally showed favorable association of the CA nutrition policies with overweight/obesity prevalence trends, although the magnitudes of associations and strengths of evidence varied among racial/ethnic subgroups. Before the CA policies went into effect (2002 to 2004), overweight/obesity prevalence increased for White, PI, and AIAN students in both grades and sex groups as well as FI girls in seventh grade. After the CA policies took place (2005 to 2012), the overweight/obesity rates decreased for almost all subgroups who experienced increasing trends before the policies, with the largest decrease seen among PI girls in fifth grade (before: log odds ratio = 0.149 (95% CI 0.108 to 0.189; p < 0.001); after: 0.010 (-0.005 to 0.025; 0.178)). When both the CA nutrition policies and HHFKA 2010 were in effect (2013 to 2016), declines in the overweight/obesity prevalence were seen among White girls and FI boys in fifth grade. Despite the evidence of the favorable association of the school nutrition policies with overweight/obesity prevalence trends, disparities between PI and AIAN students and their White peers remained large after the policies took place. As these policies went into effect for all public schools in CA, without a clear comparison group, we cannot conclude that the changes in prevalence trends were solely attributable to these policies. CONCLUSIONS: The current study found evidence of favorable associations of the state and federal school nutrition policies with overweight/obesity prevalence trends. However, the prevalence of overweight/obesity continued to be high among PI and AIAN students and FI boys. There remain wide racial/ethnic disparities between these racial/ethnic minority subgroups and their White peers. Additional strategies are needed to reduce childhood obesity and related disparities among these understudied racial/ethnic populations.

School nutrition laws in the US: do they influence obesity among youth in a racially/ethnically diverse state?

BACKGROUND/OBJECTIVES: Little is known about the separate or combined effects of state and national nutrition policies regulating food and beverages in schools on child overweight/obesity (OV/OB) and related racial/ethnic disparities. We investigated the influence of school nutrition policies enacted in California, independently and in combination with the United States' national policy "Healthy Hunger Free Kids Act" (HHFKA) on childhood OV/OB and racial/ethnic disparities. SUBJECTS/METHODS: An interrupted time series design was used with data from 12,363,089 child-level records on 5th- and 7th-graders in California public schools to estimate sex- and racial/ethnic-specific time trends in OV/OB prevalence during three periods: before the California nutrition policies (2002-2004); when only California policies were in effect (2005-2012); and when they were in effect simultaneously with HHFKA (2013-2016). RESULTS: Before the state's policies, OV/OB prevalence increased annually among children in most subgroups. Improvements in OV/OB trends were observed for almost all groups after the California policies were in effect, with further improvements after the addition of HFFKA. The total change in annual log-odds of OV/OB, comparing the periods with both state and federal policies versus no policies, ranged from -0.08 to -0.01 and varied by grade, sex, and race/ethnicity. Within each sex and grade, the greatest changes were among African-American (-0.08 to -0.02, all p < 0.05) followed by Latino children (-0.06 to -0.01, all p < 0.05). Although disparities narrowed among these groups versus White children after the dual policy period, disparities remained large. CONCLUSIONS: State and national nutrition policies for schools may have contributed to containing the upward trend in childhood OV/OB and racial/ethnic OV/OB disparities within California. However, sizable OV/OB prevalence and disparities persist. To end the epidemic, promote healthy weight and increase health equity, future efforts should strengthen state and national policies to improve food quality in schools, particularly those serving populations with the highest OV/OB prevalence.

Obstacles to preventing obesity in children aged 2 to 5 years: Latino mothers' and fathers' experiences and perceptions of their urban environments.

BACKGROUND: The prevalence of obesity among Latino children is alarmingly high, when compared to non-Latino White children. Low-income Latino parents living in urban areas, even if they are well-educated, face obstacles that shape familial health behaviors. This study used qualitative methods to explore parents' experiences in providing meals and opportunities to play to their children aged 2 to 5 years. In contrast to most prior studies, this study examined perceptions of familial behaviors among both mothers and fathers. METHODS: An ecological framework for exploring the associations of parental feeding behaviors and children's weight informed this study. An interview guide was developed to explore parents' experiences and perceptions about children's eating and physical activity and administered to six focus groups in a community-based organization in the Mission District of San Francisco. Transcripts were coded and analyzed. Twenty seven mothers and 22 fathers of Latino children ages 2 to 5 participated. RESULTS: Mothers, fathers, and couples reported that employment, day care, neighborhood environments and community relationships were experienced, and perceived as obstacles to promoting health behavior among their children, including drinking water instead of soda and participating in organized playtime with other preschool-age children. CONCLUSIONS: Results from this study suggest that the parents' demographic, social and community characteristics influence what and how they feed their children, as well as how often and the types of opportunities they provide for physical activity, providing further evidence that an ecological framework is useful for guiding research with both mothers and fathers. Mothers and fathers identified numerous community and society-level constraints in their urban environments. The results point to the importance of standardized work hours, resources for day care providers, clean and safe streets and parks, strong community relationships, and reduced access to sugar-sweetened beverages in preventing the development of obesity in preschool-age Latino children.

The relationship between food insecurity and overweight/obesity differs by birthplace and length of US residence.

OBJECTIVE: To examine whether the cross-sectional association between food insecurity and overweight/obesity varied according to birthplace and length of residence in the USA among California women. DESIGN: Using cross-sectional, population-based data from the California Women's Health Survey (CWHS) 2009-2012, we examined whether the association between food insecurity and overweight or obesity varied by birthplace-length of US residence. SETTING: California, USA. SUBJECTS: Women (n 16 008) aged 18 years or older. RESULTS: Among US-born women, very low food security (prevalence ratio (PR)=1·21; 95 % CI 1·11, 1·31) and low food security (PR=1·19; 95 % CI 1·10, 1·28) were significantly associated with higher prevalence of overweight/obesity, after controlling for age, marital status, race/ethnicity, poverty and education. Among immigrant women who lived in the USA for 10 years or longer, very low food security was significantly associated with higher prevalence of overweight/obesity, after controlling for covariates (PR=1·16; 95 % CI 1·07, 1·27). Among immigrant women who had lived in the USA for less than 10 years, low and very low food security were not significantly associated with overweight/obesity, after controlling for covariates. CONCLUSIONS: Food insecurity may be an important pathway through which weight may increase with longer US residence among immigrant women. Public health programmes and policies should focus on increasing food security for all women, including immigrant women, as one strategy to reduce the prevalence of overweight/obesity.

Hierarchical Distributed-Lag Models: Exploring Varying Geographic Scale and Magnitude in Associations Between the Built Environment and Health.

It is well known that associations between features of the built environment and health depend on the geographic scale used to construct environmental attributes. In the built environment literature, it has long been argued that geographic scales may vary across study locations. However, this hypothesized variation has not been systematically examined due to a lack of available statistical methods. We propose a hierarchical distributed-lag model (HDLM) for estimating the underlying overall shape of food environment-health associations as a function of distance from locations of interest. This method enables indirect assessment of relevant geographic scales and captures area-level heterogeneity in the magnitudes of associations, along with relevant distances within areas. The proposed model was used to systematically examine area-level variation in the association between availability of convenience stores around schools and children's weights. For this case study, body mass index (weight kg)/height (m)2) z scores (BMIz) for 7th grade children collected via California's 2001-2009 FitnessGram testing program were linked to a commercial database that contained locations of food outlets statewide. Findings suggested that convenience store availability may influence BMIz only in some places and at varying distances from schools. Future research should examine localized environmental or policy differences that may explain the heterogeneity in convenience store-BMIz associations.

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.

Latina Birth Outcomes in California: Not so Paradoxical.

Objectives To investigate Latina-White differences in birth outcomes in California from 2003 to 2010, looking for evidence of the often-cited "Latina paradox" and assessing the possible role of socioeconomic factors in observed differences. MethodsUsing statewide-representative data from the California Maternal and Infant Health Assessment, an annual population-based postpartum survey, we compared rates of preterm birth (PTB) and low birth weight (LBW) in five groups: U.S.-born non-Latina Whites ("Whites"), U.S.-born Mexican-Americans, U.S.-born non-Mexican Latinas, Mexican immigrants, and non-Mexican Latina immigrants. Logistic regression models examined the relative likelihood of PTB and LBW for women in each Latina subgroup compared with Whites, before and after adjustment for socioeconomic and other covariates. Results In unadjusted analyses, women in each Latina subgroup appeared more likely than White women to have PTB and LBW, although the increased likelihood of LBW among Mexican immigrants was statistically non-significant. After adjustment for less favorable socioeconomic characteristics among Latinas compared with Whites, observed differences in the estimated likelihoods of PTB or LBW for Latina subgroups relative to Whites were attenuated and (with the exception of PTB among U.S.-born Mexican Americans) no longer statistically significant. Conclusions We found no evidence of a "Latina paradox" in birth outcomes, which some have cited as evidence that social disadvantage is not always health-damaging. As observed in several previous studies, our findings were non-paradoxical: consistent with their socioeconomic disadvantage, Latinas had worse birth outcomes than non-Latina White women. Policy-makers should not rely on a "Latina paradox" to ensure good birth outcomes among socioeconomically disadvantaged Latina women.

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.

"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.

Trends in school-neighbourhood inequalities and youth obesity: Repeated cross-sectional analyses of the public schools in the state of California.

BACKGROUND: It is currently unknown whether the relationship between affluence of school neighbourhoods and prevalence of youth overweight/obesity is uniform across demographic subgroups and areal context in the United States. METHODS: We examined association between school-neighbourhood income tertiles and school-level overweight/obesity (OVOB) prevalence, using data on body mass index of fifth, seventh, and nineth graders who attended public schools in California in 2001 and 2010 (n = 1 584 768), using multiple logistic regression models. RESULTS: Overall, OVOB prevalence was higher in lower-income school neighbourhoods, with a steeper income-OVOB gradient for girls. Among boys, the gradient became steeper in 2010 than 2000. Among Asian and White girls, the negative gradients were steepest in rural areas. For African-American students in all areas and Latino boys in rural areas, there was less clear evidence of inverse income-OVOB gradients. Addition of fast-food restaurant availability to the models did not change the observed inverse school-neighbourhood income-obesity gradients. CONCLUSIONS: The findings suggest the needs to investigate reasons for this variability with consideration to combinations of sociodemographic, economic, and environmental risk factors that may contribute to disparities in childhood obesity.

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

Epidemiologic studies have observed influences of the food environment near schools on children's overweight status but have not systematically assessed the associations by race, sex, and grade. The authors examined whether the associations between franchised fast food restaurant or convenience store density near schools and overweight varied by these factors using data for 926,018 children (31.3% white, 55.1% Hispanic, 5.7% black, and 8% Asian) in fifth, seventh, or ninth grade, nested in 6,362 schools. Cross-sectional data were from the 2007 California physical fitness test (also known as "Fitnessgram"), InfoUSA, the California Department of Education, and the 2000 US Census. In adjusted models, the overweight prevalence ratio comparing children in schools with 1 or more versus 0 fast food restaurants was 1.02 (95% confidence interval (CI): 1.01, 1.03), with a higher prevalence ratio among girls compared with boys. The association varied by student's race/ethnicity (P = 0.003): Among Hispanics, the prevalence ratio = 1.02 (95% CI: 1.01, 1.03); among blacks, the prevalence ratio = 1.03 (95% CI: 1.00, 1.06), but among Asians the prevalence ratio = 0.94 (95% CI: 0.91, 0.97). For each additional convenience store, the prevalence ratio was 1.01 (95% CI: 1.00, 1.01), with a higher prevalence ratio among fifth grade children. Nuanced understanding of the impact of food environments near schools by race/ethnicity, sex, and grade may help to elucidate the etiology of childhood overweight and related race/ethnic disparities.

Adverse childhood experiences and cognitive disability in the 2019 United States behavioral risk factor surveillance system.

A growing number of studies have found associations between adverse childhood experiences (ACEs) and adult well-being, with disparities between subpopulations. Limited research exists about the association between ACEs and cognitive disability, and variations by race and ethnicity. This study reports a cross-sectional analysis of 2019 Behavioral Risk Factor Surveillance System (BRFSS) data (n = 93 692) conducted in 2021. Logistic regression models examined the association between ACEs and cognitive disability (as defined by serious difficulty concentrating, remembering or making decisions because of a physical, mental, or emotional condition) and whether the association varied by race and ethnicity, adjusting for demographics, (age, gender, marital status), socioeconomic factors (income and education), and perceived general health. Exposures to 1, 2, 3, and 4 or more ACEs were associated with elevated odds of cognitive disability; the association varied by race and ethnicity (p for interaction less than 0.05). In stratified analyses, ACEs were positively associated with cognitive disability among the American Indian/Alaskan Native group, though significant only among those reporting 4 ACEs or more (OR: 2.89; 95% CI 1.25, 6.66). A dose response was observed for Black, White and Hispanic groups though the association was larger among Hispanic respondents. The elevated odds of cognitive disability associated with ACEs warrant additional research to understand mechanisms underlying this relationship across racial and ethnic groups. Additionally, interventions to prevent cognitive disability may benefit from considering ACEs across all populations, particularly among those with highest prevalence.

Racial/ethnic disparities in childhood obesity: The role of school segregation.

OBJECTIVE: Recent studies have observed that racial or ethnic adult health disparities revealed in national data dissipate in racially integrated communities, supporting the theory that "place, not race" shapes the nature and magnitude of racial/ethnic health disparities. This study tested this theory among children. METHODS: In 2020, the racial/ethnic childhood obesity disparities within integrated schools and between segregated schools were estimated using statewide cross-sectional data collected in 2019 on fifth, seventh, and ninth grade students from California public schools. RESULTS: School segregation accounted for a large part of the obesity disparities between White children and children of color (Latino, Black, and Filipino children). In racially integrated schools, obesity disparities were much smaller than those in statewide data, whereas racial or ethnic childhood obesity disparities were larger when comparing children in majority-White schools with those attending schools with a majority enrollment of children of color, except for Asian children, who generally had lower obesity rates than their White peers. CONCLUSIONS: School-level racial segregation is a salient contributor to racial/ethnic childhood obesity disparities. Reducing obesity disparities may be particularly effective if place-level interventions target socioeconomically disadvantaged integrated schools and segregated schools attended primarily by children of color.

Competitive Food and Beverage Policies and Obesity among Middle School Students: Variability by Urbanicity in California.

Introduction: This study examined the association between California school nutrition policies and population-level trends in childhood overweight/obesity by levels of urbanicity. Methods: We used interrupted time series with Fitnessgram data on overweight/obesity from the period 2002 to 2010 pertaining to African American, Latino, Asian, and White students in seventh grades who attended California public schools. We used multilevel logistic regression models to examine the impact of the introduction of successive California school nutrition policies on overweight/obesity prevalence, stratified by gender and adjusted for school district-, school-, and student-level characteristics. Results: At the start of the study period, rural areas and second cities (i.e., population centers with lower population densities than urban areas) had relatively low prevalence, but experienced sharp increases in 2002-2004, leading to higher prevalence of overweight/obesity than suburban areas. There was evidence of beneficial policy influences on overweight/obesity in most areas, except for girls in urban areas and boys in second cities. The evidence of beneficial changes was strongest among children attending schools located in rural areas, and boys in suburban and urban areas. These results persisted even after we accounted for differences in racial/ethnic compositions, socioeconomic characteristics of the schools and school neighborhoods, and school sizes, as well as child-level race/ethnicity, age, and student fitness levels. Conclusion: Despite evidence of beneficial policy impact, childhood obesity prevalence remains high, especially in urban areas in California. Additional policies and environmental interventions are recommended to address obesogenic risk factors unique to each area.

Physical activity strategies in low-resource elementary schools: Why and how are they prioritized?

Most US children do not achieve the recommended daily 60 minutes of moderate to vigorous physical activity (PA). Schools are ideal settings to promote PA given their reach to large child populations, including students with less resources and limited access to PA opportunities. Although limited in numbers, schools that offer enough PA strategies can provide insights to increase PA in these settings. However, few studies have examined why and how these schools successfully prioritize PA strategies, particularly schools serving socioeconomically disadvantaged student populations. This qualitative study of low-resource, PA-supportive schools was conducted during 2017-2018 to obtain in-depth information about why and how schools make decisions to prioritize and implement PA strategies. Forty-two study participants in 17 states plus Washington DC were recruited. Content analysis revealed the following themes: (1) Schools prioritize PA because it helps advance learning and health goals; (2) Policies and standards for PA/PE reinforce the importance of PA; (3) A culture of learning and health advances decisions to offer PA; (4) Advocates play a key role in generating support to integrate PA; (5) Stakeholder buy-in enables decisions to offer PA opportunities; (6) Collaboration focused on PA specifically can facilitate decisions to increase PA strategies; and (7) Funding and resources drive decisions to put PA strategies into practice. The study findings offer insights that may be useful in efforts to increase access to PA opportunities in low-resource elementary schools.

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.