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

Access to healthy food retailers among formerly incarcerated individuals

OBJECTIVE

To assess access to healthy food retailers among formerly incarcerated individuals.

DESIGN

Using linked data from the National Longitudinal Study of Adolescent to Adult Health and the Modified Retail Food Environment Index, the present study applies multivariate logistic regression to assess the association between incarceration and (i) living in a food desert and (ii) having low access to healthy food retailers. To account for unobserved heterogeneity, additional analyses are performed comparing formerly incarcerated individuals with persons arrested or convicted for a crime but not previously incarcerated.

SETTING

Sample of respondents living in urban census tracts in the USA.

SUBJECTS

Adults (n 10390) aged 24-34 years.

RESULTS

In adjusted logistic regression models, prior incarceration was not significantly associated with living in a food desert (OR=1·097; 95% CI 0·896, 1·343). Prior incarceration significantly increased the likelihood of living in a census tract with low access to healthy food retailers (OR=1·265; 95% CI 1·069, 1·498). This significant association remained when comparing formerly incarcerated individuals with those who had been arrested or convicted of a crime, but not previously incarcerated (OR=1·246; 95% CI 1·032, 1·503).

CONCLUSIONS

Formerly incarcerated individuals are more likely to live in areas with low access to healthy food retailers compared with their non-incarcerated counterparts. Because lower access healthy food retailers may be associated with worse health and dietary behaviour, disparities in local food retail environments may exacerbate health inequalities among formerly incarcerated individuals.

Using social media to assess the consumer nutrition environment: comparing Yelp reviews with a direct observation audit instrument for grocery stores

OBJECTIVE

To examine the feasibility of using social media to assess the consumer nutrition environment by comparing sentiment expressed in Yelp reviews with information obtained from a direct observation audit instrument for grocery stores.

DESIGN

Trained raters used the Nutrition Environment Measures Survey in Stores (NEMS-S) in 100 grocery stores from July 2015 to March 2016. Yelp reviews were available for sixty-nine of these stores and were retrieved in February 2017 using the Yelp Application Program Interface. A sentiment analysis was conducted to quantify the perceptions of the consumer nutrition environment in the review text. Pearson correlation coefficients (ρ) were used to compare NEMS-S scores with Yelp review text on food availability, quality, price and shopping experience.

SETTING

Detroit, Michigan, USA.ParticipantsNone.

RESULTS

Yelp reviews contained more comments about food availability and the overall shopping experience than food price and food quality. Negative sentiment about food prices in Yelp review text and the number of dollar signs on Yelp were positively correlated with observed food prices in stores (ρ=0·413 and 0·462, respectively). Stores with greater food availability were rated as more expensive on Yelp. Other aspects of the food store environment (e.g. overall quality and shopping experience) were captured only in Yelp.

CONCLUSIONS

While Yelp cannot replace in-person audits for collecting detailed information on the availability, quality and cost of specific food items, Yelp holds promise as a cost-effective means to gather information on the overall cost, quality and experience of food stores, which may be relevant for nutrition outcomes.

Obesogenic Environment Case Study from a Food and Nutrition Security Perspective: Hermosillo City

Obesity and certain nutritional deficiencies are global health problems that emerge in systems of interdependent individual biological and historical factors and social environmental determinants of health. Nutrition security is a framework that assumes stable access to sufficient innocuous and nutritious food (i.e., food security), health care, and sanitation, and information that in conjunction allows self-care-oriented behavior for health protection. To understand the social environment of nutrition insecurity, the object of study was the food distribution and consumption system of a marginalized community in Hermosillo, Mexico. We assessed the distribution of food establishments by social marginalization level in basic geo-statistical areas and the nutrition security status of women in underserved neighborhoods. We found that in Hermosillo >90% of food establishments included for analysis (grocery stores, supermarkets, convenience stores, and beer deposits) were distributed outside of areas with high levels of social marginalization. The nutrition security assessment suggests that low intakes of fruit and vegetables and high intakes of fat and sugar may be associated with food accessibility and acceptability factors in individual decision-making processes. Future research should take into account the variability of food system environments and address the particular needs of communities in terms of food and nutrition security.

Urban food environments in Africa: implications for policy and research

Africa is currently experiencing rapid urbanisation impacting on people's food environments and dietary habits. Such changes are associated with higher prevalence of obesity coexisting with undernutrition. The present paper provides an overview of the healthiness of African urban food environments. We discuss the ways that food environments can be characterised and summarise the methods that can be used to investigate and intervene in the food environment. Data for Africa over a 50-year period (1961–2013) suggest an increasing availability of energy, animal products, fruit and vegetables, vegetable oils, sugar and sweeteners but a decrease in animal fats. There is a lack of evidence about how social, physical and macro-environments drive dietary habits in urban Africa, as most research has focused on the individual level. Examining how food consumption is embedded in everyday life, by investigating social environments is crucial to developing effective interventions. The informal food sector plays an important role in the retail food environment. Macro-level food price changes are an important factor influencing nutritional quality of African diets. The rapid expansion of food/beverages advertising in Africa threatens traditional food habits. Liberalisation of food trade is already impacting on the nutritional quality of food available. Improving African food environments represents a pressing public health concern and has the potential to prevent all forms of malnutrition. Hence, by conducting research into the role of urban social, physical and macro-environments, emerging interventions and policies are likely to positively impact on nutritional status, thereby enhancing social and economic development.

The association between food deserts and short sleep duration among young adults in the United States: variation by race and ethnicity

BACKGROUND

Both food deserts and short sleep duration are serious public health problems that affect the lives of millions of Americans. Although recent research has begun to link community characteristics to sleep problems, the relationship between living in a food desert and sleep behavior has gone largely unexplored.

METHODS

Using data from the National Longitudinal Study from Adolescent to Adult Health and data on food retailers from the Modified Retail Food Environment Index, this study applies multivariable logistic regression to assess the association between living in a food desert and short sleep duration. Models were stratified by race and ethnicity to examine potential moderating effects. Supplemental analyses are conducted where the comparison category is restricted to respondents who live in census tracts with low access to healthy food retailers but do not live in food deserts.

RESULTS

In adjusted logistic regression models, living in a food desert is not associated with short sleep duration. When the sample is stratified, living in a food desert has a positive and significant association with short sleep duration among Hispanic respondents in both the main analysis (odds ratio = 1.7; 95% confidence interval = 1.0-2.7) and supplemental models (odds ratio = 1.9; 95% confidence interval = 1.2-3.2).

CONCLUSIONS

Living in a food desert is not associated with short sleep duration among young adults. Study results indicate that living in a food desert is associated with increased odds for short sleep duration among Hispanics. Potential explanations for this finding are discussed in the context of extant research.

Status report - Geographic retail food environment measures for use in public health

The Association of Public Health Epidemiologists in Ontario (APHEO) Core Indicators Work Group standardizes definitions and calculation methods for over 120 public health indicators to enhance accurate and standardized community health status reporting across public health units in Ontario. The Built Environment Subgroup is a multi-disciplinary group made up of planners, researchers, policy analysts, registered dietitians, geographic information systems (GIS) analysts and epidemiologists. The Subgroup selected and operationalized a suite of objective, standardized indicators intended to help public health units and regional health authorities assess their community retail food environments. The Subgroup proposed three indicators that use readily available data sources and GIS tools to characterize geographic access to various types of retail food outlets within neighbourhoods in urban settings. This article provides a status report on the development of these food environment indicators.

The Nutritional Quality of Lunch Meals Eaten at Danish Worksites

Monitoring the nutritional environment is important to help inform future initiatives to improve access to healthy foods. The objective was to examine the nutritional quality of lunch meals eaten at 15 worksite canteens and then to compare with results from a study conducted 10 years before. The duplicate-portion-technique with subsequent chemical analysis was used to quantify 240 customers' lunch intake. Estimated mean energy intake was 2.1 MJ/meal (95% confidence interval (CI): 1.9 to 2.4 g/meal) and estimated energy density 599 kJ/100 g (95% CI 550 to 653 kJ/100 g). Energy density of the male participants' meals were significantly higher compared with the female participants' meals (+55 kJ/100 g, 95% CI: +12 to +98 kJ/100 g, p = 0.012), whereas no gender differences were found in macronutrient distribution or fruit and vegetable intake. Compared to the study conducted 10 years before several significant changes were observed, including an increase in mean estimated intake of fruit and vegetables (+38 g/meal, 95% CI: 19 to 57 g/meal, p < 0.001) and a decrease in energy density (-76 kJ/100 g, 95% CI: -115, -37 kJ/100 g, p < 0.001). In conclusion, this study suggests an equalization of gender differences in fruit and vegetable intake and a possible improvement in the nutritional quality of canteen lunch meals over a 10-year period.

Local Retail Food Environment and Consumption of Fruit and Vegetable among Adults in Hong Kong

Outside of western countries, the study of the local food environment and evidence for its association with dietary behavior is limited. The aim of this paper was to examine the association between the local retail food environment and consumption of fruit and vegetables (FV) among adults in Hong Kong. Local retail food environment was measured by density of different types of retail food outlets (grocery stores, convenience stores, and fast food restaurants) within a 1000 m Euclidean buffer around individual's homes using a geographic information system (GIS). The Retail Food Environment Index (RFEI) was calculated based on the relative density of fast-food restaurants and convenience stores to grocery stores. Logistic regressions were performed to examine associations using cross-sectional data of 1977 adults (18 years or older). Overall, people living in an area with the highest RFEI (Q4, >5.76) had significantly greater odds of infrequent FV consumption (<7 days/week) after covariates adjustment (infrequent fruit consumption: OR = 1.36, 95% CI 1.04⁻1.78; infrequent vegetable consumption: OR = 1.72, 95% CI 1.11⁻2.68) in comparison to the lowest RFEI (Q1, <2.25). Highest density of fast food restaurants (Q4, >53) was also significantly associated with greater odds of infrequent fruit consumption (<7 days/week) (unadjusted model: OR = 1.34, 95% CI 1.04⁻1.73), relative to lowest density of fast food restaurants (Q1, <13). No significant association of density of grocery stores or convenience stores was observed with infrequent FV consumption regardless of the covariates included in the model. Our results suggest that the ratio of fast-food restaurants and convenience stores to grocery stores near people's home is an important environmental factor in meeting fruit and vegetable consumption guidelines. "Food swamps" (areas with an abundance of unhealthy foods) rather than "food deserts" (areas where there is limited access to healthy foods) seems to be more of a problem in Hong Kong's urban areas. We advanced international literature by providing evidence in a non-western setting.

A Nutrition Environment Measure to Assess Tribal Convenience Stores: The THRIVE Study

In rural American Indian (AI) communities, where supermarkets are rare, tribally owned and operated convenience stores are an important food source. Food environment measures for these settings are needed to understand and address the significant diet-related disparities among AIs. Through a tribal-university partnership that included tribal health and commerce representatives from two Native Nations in rural southeastern Oklahoma, we developed the Nutrition Environment Measures Survey for Tribal Convenience Stores (NEMS-TCS) to inform the development and evaluation of a healthy food retail intervention. The NEMS-TCS assessed four scored domains of the rural convenience store food environment-food availability, pricing, quality, and placement-and included 11 food categories that emphasized ready-to-eat food items. Trained raters administered the NEMS-TCS using a sample of 18 rural convenience stores (primarily ranging between 2,400 and 3,600 square feet). We assessed interrater reliability with kappa statistics for dichotomized variables and intraclass correlation coefficients (ICC) for continuous variables. NEMS-TCS demonstrated high inter-rater reliability for all food categories (>85% agreement), subscores (ICC = 0.73-1.00), and the total score (ICC = 0.99). The NEMS-TCS responds to recent calls for reliable measures for rural food environments and may be valuable for studying food environments of large convenience stores in other Native Nations as well as other rural settings.

Change in an Urban Food Environment: Storefront Sources of Food/Drink Increasing Over Time and Not Limited to Food Stores and Restaurants

BACKGROUND

Local food environments include food stores (eg, supermarkets, grocery stores, bakeries) and restaurants. However, the extent to which other storefront businesses offer food/drink is not well described, nor is the extent to which food/drink availability through a full range of storefront businesses might change over time.

OBJECTIVES

This study aimed to assess food/drink availability from a full range of storefront businesses and the change over time and to consider implications for food-environment research.

DESIGN

Investigators compared direct observations from 2010 and 2015.

PARTICIPANTS/SETTING

Included were all storefront businesses offering foods/drinks on 153 street segments in the Bronx, NY.

MAIN OUTCOME MEASURES

The main outcome was change between 2010 and 2015 as determined by matches between businesses. Matches could be strict (businesses with the same name on the same street segment in both years) or lenient (similar businesses on the same street segment in both years). Investigators categorized businesses as general grocers, specialty food stores, restaurants, or other storefront businesses (eg, barber shops/beauty salons, clothing outlets, hardware stores, laundromats, and newsstands).

STATISTICAL ANALYSES PERFORMED

Investigators quantified change, specifically calculating how often businesses in 2015 were present in 2010 and vice versa.

RESULTS

Strict matches for businesses in 2015 present in 2010 ranged from 29% to 52%, depending on business category; lenient matches ranged from 43% to 72%. Strict matches for businesses in 2010 present in 2015 ranged from 34% to 63%; lenient matches ranged from 72% to 83%. In 2015 compared with 2010, on 22% more of the sampled street segments, 30% more businesses were offering food/drink: 66 vs 46 general grocers, 22 vs 19 specialty food stores, 99 vs 99 restaurants, 98 vs 56 other storefront businesses.

CONCLUSIONS

Over 5 years, an urban food environment changed substantially, even by lenient standards, particularly among "other storefront businesses" and in the direction of markedly greater food availability (more businesses offering food on more streets). Failure to consider a full range of food/drink sources and change in food/drink sources could result in erroneous food-environment conclusions.

An Analytical Framework for Integrating the Spatiotemporal Dynamics of Environmental Context and Individual Mobility in Exposure Assessment: A Study on the Relationship between Food Environment Exposures and Body Weight

In past studies, individual environmental exposures were largely measured in a static manner. In this study, we develop and implement an analytical framework that dynamically represents environmental context (the environmental context cube) and effectively integrates individual daily movement (individual space-time tunnel) for accurately deriving individual environmental exposures (the environmental context exposure index). The framework is applied to examine the relationship between food environment exposures and the overweight status of 46 participants using data collected with global positioning systems (GPS) in Columbus, Ohio, and binary logistic regression models. The results indicate that the proposed framework generates more reliable measurements of individual food environment exposures when compared to other widely used methods. Taking into account the complex spatial and temporal dynamics of individual environmental exposures, the proposed framework also helps to mitigate the uncertain geographic context problem (UGCoP). It can be used in other environmental health studies concerning environmental influences on a wide range of health behaviors and outcomes.

Development of the 'Canteen Scan': an online tool to monitor implementation of healthy canteen guidelines

Background

To improve the availability and accessibility of healthier food and drinks in schools, sports and worksites canteens, national Guidelines for Healthier Canteens were developed by the Netherlands Nutrition Centre. Until now, no tool was available to monitor implementation of these guidelines. This study developed and assessed the content validity and usability of an online tool (the ‘Canteen Scan’) that provides insight into and directions for improvement of healthier food products in canteens.

Methods

The Canteen Scan was developed using a three-step iterative process. First, preliminary measures and items to evaluate adherence to the guidelines were developed based on literature, and on discussions and pre-tests with end-users and experts from science, policy and practice. Second, content validity of a paper version of the Canteen Scan was assessed among five end-users. Third, the online Canteen Scan was pilot tested among end-users representing school canteens. Usability was measured by comprehensibility, user-friendliness, feasibility, time investment, and satisfaction.

Results

The content validity of the Canteen Scan was ensured by reaching agreement between stakeholders representing science, policy and practice. The scan consists of five elements: 1) basic conditions (e.g. encouragement to drink water and availability of policy regarding the guidelines), 2) product availability offered on displays (counter, shelf) and 3) in vending machines, 4) product accessibility (e.g. promotion and placement of products), and 5) an overall score based on the former elements and tailored feedback for creating a healthier canteen. The scan automatically classifies products into healthier or less healthy products. Pilot tests indicated good usability of the tool, with mean scores of 4.0–4.6 (5-point Likert scale) on the concepts comprehensibility, user-friendliness and feasibility.

Conclusion

The Canteen Scan provides insight into the extent to which canteens meet the Dutch Guidelines for Healthier Canteens. It also provides tailored feedback to support adjustments towards a healthier canteen and with the scan changes over time can be monitored. Pilot tests show this tool to be usable in practice.

Unexpected Neighborhood Sources of Food and Drink: Implications for Research and Community Health

INTRODUCTION

Studies of neighborhood food environments typically focus on select stores (especially supermarkets) and/or restaurants (especially fast-food outlets), make presumptions about healthfulness without assessing actual items for sale, and ignore other kinds of businesses offering foods/drinks. The current study assessed availability of select healthful and less-healthful foods/drinks from all storefront businesses in an urban environment and considered implications for food-environment research and community health.

METHODS

Cross-sectional assessment in 2013 of all storefront businesses (n=852) on all street segments (n=1,253) in 32 census tracts of the Bronx, New York. Investigators assessed for healthful items (produce, whole grains, nuts, water, milk) and less-healthful items (refined sweets, salty/fatty fare, sugar-added drinks, and alcohol), noting whether items were from food businesses (e.g., supermarkets and restaurants) or other storefront businesses (OSB, e.g., barber shops, gyms, hardware stores, laundromats). Data were analyzed in 2017.

RESULTS

Half of all businesses offered food/drink items. More than one seventh of all street segments (more than one third in higher-poverty census tracts) had businesses selling food/drink. OSB accounted for almost one third of all businesses offering food/drink items (about one quarter of businesses offering any healthful items and more than two thirds of businesses offering only less-healthful options).

CONCLUSIONS

Food environments include many businesses not primarily focused on selling foods/drinks. Studies that do not consider OSB may miss important food/drink sources, be incomplete and inaccurate, and potentially misguide interventions. OSB hold promise for improving food environments and community health by offering healthful items; some already do.

Food environments and dietary intakes among adults: does the type of spatial exposure measurement matter? A systematic review

BACKGROUND

The relationships between food environments and dietary intake have been assessed via a range of methodologically diverse measures of spatial exposure to food outlets, resulting in a largely inconclusive body of evidence, limiting informed policy intervention.

OBJECTIVE

This systematic review aims to evaluate the influence of methodological choice on study outcomes by examining the within-study effect of availability (e.g., counts) versus accessibility (e.g., proximity) spatial exposure measures on associations with diet.

METHODS

(PROSPERO registration: CRD42018085250). PubMed, Web of Science, Scopus and ScienceDirect databases were searched for empirical studies from 1980 to 2017, in the English language, involving adults and reporting on the statistical association between a dietary outcome and spatial exposure measures of both availability and accessibility. Studies were appraised using an eight-point quality criteria with a narrative synthesis of results.

RESULTS

A total of 205 associations and 44 relationships (i.e., multiple measures of spatial exposure relating to a particular food outlet type and dietary outcome) were extracted from 14 eligible articles. Comparative measures were dominated by counts (availability) and proximity (accessibility). Few studies compared more complex measures and all counts were derived from place-based measures of exposure. Sixteen of the 44 relationships had a significant effect involving an availability measure whilst only 8 had a significant effect from an accessibility measure. The largest effect sizes in relationships were mostly for availability measures. After stratification by scale, availability measure had the greatest effect size in 139 of the 176 pairwise comparisons. Of the 33% (68/205) of associations that reached significance, 53/68 (78%) were from availability measures. There was no relationship between study quality and reported study outcomes.

CONCLUSIONS

The limited evidence suggests that availability measures may produce significant and greater effect sizes than accessibility measures. However, both availability and accessibility measures may be important concepts of spatial exposure depending on the food outlet type and dietary outcome examined. More studies reporting on multi-method effects are required to differentiate findings by the type of spatial exposure assessment and build an evidence base regarding the appropriateness and robustness of measures under different circumstances.

Neighbourhood typologies and associations with body mass index and obesity: A cross-sectional study

Little research has investigated associations between a combined measure of the food and physical activity (PA) environment, BMI (body-mass-index) and obesity. Cross-sectional data (n=22,889, age 18-86years) from the Yorkshire Health Study were used [2010-2013]. BMI was calculated using self-reported height and weight; obesity=BMI≥30. Neighbourhood was defined as a 2km radial buffer. Food outlets and PA facilities were sourced from Ordnance Survey Points of Interest (PoI) and categorised into 'fast-food', 'large supermarkets', 'convenience and other food retail outlets' and 'physical activity facilities'. Parks were sourced from Open Street Map. Latent class analysis was conducted on these five environmental variables and availability was defined by quartiles of exposure. Linear and logistic regressions were then conducted for BMI and obesity respectively for different neighbourhood types. Models adjusted for age, gender, ethnicity, area-level deprivation, and rural/urban classification. A five-class solution demonstrated best fit and was interpretable. Neighbourhood typologies were defined as; 'low availability', 'moderate availability', 'moderate PA, limited food', 'saturated' and 'moderate PA, ample food'. Compared to low availability, one typology demonstrated lower BMI (saturated, b=-0.50, [95% CI=-0.76, -0.23]), while three showed higher BMI (moderate availability, b=0.49 [0.27, 0.72]; moderate PA, limited food, b=0.30 [0.01, 0.59]; moderate PA, ample food, b=0.32 [0.08, 0.57]). Furthermore, compared to the low availability, saturated neighbourhoods showed lower odds of obesity (OR=0.86 [0.75, 0.99]) while moderate availability showed greater odds of obesity (OR=1.18 [1.05, 1.32]). This study supports population-level approaches to tackling obesity however neighbourhoods contained features that were health-promoting and -constraining.

Examining the validity and utility of two secondary sources of food environment data against street audits in England

Background

Secondary data containing the locations of food outlets is increasingly used in nutrition and obesity research and policy. However, evidence evaluating these data is limited. This study validates two sources of secondary food environment data: Ordnance Survey Points of Interest data (POI) and food hygiene data from the Food Standards Agency (FSA), against street audits in England and appraises the utility of these data.

Methods

Audits were conducted across 52 Lower Super Output Areas in England. All streets within each Lower Super Output Area were covered to identify the name and street address of all food outlets therein. Audit-identified outlets were matched to outlets in the POI and FSA data to identify true positives (TP: outlets in both the audits and the POI/FSA data), false positives (FP: outlets in the POI/FSA data only) and false negatives (FN: outlets in the audits only). Agreement was assessed using positive predictive values (PPV: TP/(TP + FP)) and sensitivities (TP/(TP + FN)). Variations in sensitivities and PPVs across environment and outlet types were assessed using multi-level logistic regression. Proprietary classifications within the POI data were additionally used to classify outlets, and agreement between audit-derived and POI-derived classifications was assessed.

Results

Street audits identified 1172 outlets, compared to 1100 and 1082 for POI and FSA respectively. PPVs were statistically significantly higher for FSA (0.91, CI: 0.89–0.93) than for POI (0.86, CI: 0.84–0.88). However, sensitivity values were not different between the two datasets. Sensitivity and PPVs varied across outlet types for both datasets. Without accounting for this, POI had statistically significantly better PPVs in rural and affluent areas. After accounting for variability across outlet types, FSA had statistically significantly better sensitivity in rural areas and worse sensitivity in rural middle affluence areas (relative to deprived). Audit-derived and POI-derived classifications exhibited substantial agreement (p < 0.001; Kappa = 0.66, CI: 0.63–0.70).

Conclusions

POI and FSA data have good agreement with street audits; although both datasets had geographic biases which may need to be accounted for in analyses. Use of POI proprietary classifications is an accurate method for classifying outlets, providing time savings compared to manual classification of outlets.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12937-017-0302-1) contains supplementary material, which is available to authorized users.

Modest ratios of fast food outlets to supermarkets and green grocers are associated with higher body mass index: Longitudinal analysis of a sample of 15,229 Australians aged 45 years and older in the Australian National Liveability Study

Food purchasing decisions are made within the context of the range of options available, yet most epidemiological studies focus upon single outlet types. Ratios of fast food outlets to supermarkets and green grocers were linked to addresses of 15,229 adults in the 45 and Up Study at baseline (2006-2008) and follow-up (2009-2010). Compared to having no fast food outlet but having healthy food outlets within 3.2km from home, multilevel growth curves revealed that relative exposure>25% fast food outlets were associated with 0.36-1.19kg/m² higher BMI (p<0.05). These associations were consistent as people aged. No associations were observed for food outlets<0.8km.

A Cluster Randomized Trial to Promote Healthy Menu Items for Children: The Kids' Choice Restaurant Program

Evidence indicates that restaurant-based interventions have the potential to promote healthier purchasing and improve the nutrients consumed. This study adds to this body of research by reporting the results of a trial focused on promoting the sale of healthy child menu items in independently owned restaurants. Eight pair-matched restaurants that met the eligibility criteria were randomized to a menu-only versus a menu-plus intervention condition. Both of the conditions implemented new healthy child menu items and received support for implementation for eight weeks. The menu-plus condition also conducted a marketing campaign involving employee trainings and promotional materials. Process evaluation data captured intervention implementation. Sales of new and existing child menu items were tracked for 16 weeks. Results indicated that the interventions were implemented with moderate to high fidelity depending on the component. Sales of new healthy child menu items occurred immediately, but decreased during the post-intervention period in both conditions. Sales of existing child menu items demonstrated a time by condition effect with restaurants in the menu-plus condition observing significant decreases and menu-only restaurants observing significant increases in sales of existing child menu items. Additional efforts are needed to inform sustainable methods for improving access to healthy foods and beverages in restaurants.

Best practices for using natural experiments to evaluate retail food and beverage policies and interventions

Policy and programmatic change in the food retail setting, including excise taxes on beverages with added-caloric sweeteners, new supermarkets in food deserts, and voluntary corporate pledges, often require the use of natural experimental evaluation for impact evaluation when randomized controlled trials are not possible. Although natural experimental studies in the food retail setting provide important opportunities to test how nonrandomized interventions affect behavioral and health outcomes, researchers face several key challenges to maintaining strong internal and external validity when conducting these studies. Broadly, these challenges include 1) study design and analysis; 2) selection of participants, selection of measures, and obtainment of data; and 3) real-world considerations. This article addresses these challenges and different approaches to meeting them. Case studies are used to illustrate these approaches and to highlight advantages and disadvantages of each approach. If the trade-offs required to address these challenges are carefully considered, thoughtful natural experimental evaluations can minimize bias and provide critical information about the impacts of food retail interventions to a variety of stakeholders, including the affected population, policymakers, and food retailers.

Greater access to healthy food outlets in the home and school environment is associated with better dietary quality in young children

OBJECTIVE

To explore associations between dietary quality and access to different types of food outlets around both home and school in primary school-aged children.

DESIGN

Cross-sectional observational study.

SETTING

Hampshire, UK.

SUBJECTS

Children (n 1173) in the Southampton Women's Survey underwent dietary assessment at age 6 years by FFQ and a standardised diet quality score was calculated. An activity space around each child's home and school was created using ArcGIS. Cross-sectional observational food outlet data were overlaid to derive four food environment measures: counts of supermarkets, healthy specialty stores (e.g. greengrocers), fast-food outlets and total number of outlets, and a relative measure representing healthy outlets (supermarkets and specialty stores) as a proportion of total retail and fast-food outlets.

RESULTS

In univariate multilevel linear regression analyses, better diet score was associated with exposure to greater number of healthy specialty stores (β=0·025 sd/store: 95 % CI 0·007, 0·044) and greater exposure to healthy outlets relative to all outlets in children's activity spaces (β=0·068 sd/10 % increase in healthy outlets as a proportion of total outlets, 95 % CI 0·018, 0·117). After adjustment for mothers' educational qualification and level of home neighbourhood deprivation, the relationship between diet and healthy specialty stores remained robust (P=0·002) while the relationship with the relative measure weakened (P=0·095). Greater exposure to supermarkets and fast-food outlets was associated with better diet only in the adjusted models (P=0·017 and P=0·014, respectively).

CONCLUSIONS

The results strengthen the argument for local authorities to increase the number of healthy food outlets to which young children are exposed.

Investigating the Spatial Dimension of Food Access

The purpose of this article is to investigate the sensitivity of food access models to a dataset’s spatial distribution and the empirical definition of food access, which contributes to understanding the mixed findings of previous studies. Data was collected in the Dan River Region in the United States using a telephone survey for individual-level variables (n = 784) and a store audit for the location of food retailers and grocery store quality. Spatial scanning statistics assessed the spatial distribution of obesity and detected a cluster of grocery stores overlapping with a cluster of obesity centered on a grocery store suggesting that living closer to a grocery store increased the likelihood of obesity. Logistic regression further examined this relationship while controlling for demographic and other food environment variables. Similar to the cluster analysis results, increased distance to a grocery store significantly decreased the likelihood of obesity in the urban subsample (average marginal effects, AME = −0.09, p-value = 0.02). However, controlling for grocery store quality nullified these results (AME = −0.12, p-value = 0.354). Our findings suggest that measuring grocery store accessibility as the distance to the nearest grocery store captures variability in the spatial distribution of the health outcome of interest that may not reflect a causal relationship between the food environment and health.