Early Results of a Natural Experiment Evaluating the Effects of a Local Minimum Wage Policy on the Diet-Related Health of Low-Wage Workers, 2018-2020

ABSTRACT Objective: This study presents results of a midpoint analysis of an ongoing natural experiment evaluating the diet-related effects of the Minneapolis Minimum Wage Ordinance, which incrementally increases the minimum wage to $15/hr. Design: A difference-in-difference (DiD) analysis of measures collected among low-wage workers in two U.S. cities (one city with a wage increase policy and one comparison city). Measures included employment-related variables (hourly wage, hours worked, and non-employment assessed by survey questions with wages verified by paystubs), body mass index measured by study scales and stadiometers, and diet-related mediators (food insecurity, Supplemental Nutrition Assistance Program (SNAP) participation, and daily servings of fruits and vegetables, whole-grain rich foods, and foods high in added sugars measured by survey questions). Setting: Minneapolis, Minnesota and Raleigh, North Carolina Participants: A cohort of 580 low-wage workers (268 in Minneapolis, 312 in Raleigh) who completed three annual study visits between 2018 and 2020. Results: In DiD models adjusted for time-varying and non-time-varying confounders, there were no statistically significant differences in variables of interest in Minneapolis compared with Raleigh. Trends across both cities were evident, showing a steady increase in hourly wage, stable body mass index, an overall decrease in food insecurity, and non-linear trends in employment, hours worked, SNAP participation, and dietary outcomes. Conclusion: There was no evidence of a beneficial or adverse effect of the Minimum Wage Ordinance on health-related variables during a period of economic and social change. The COVID-19 pandemic and other contextual factors likely contributed to the observed trends in both cities

Construct validity of the Charitable Food Nutrition Index

Background: Food pantries are an important source of food for those facing food insecurity. The Charitable Food Nutrition Index (CFNI) was developed for research and practice to measure the nutritional quality of assortments of foods in this setting. Objective: The study assessed the construct validity of the CFNI using secondary data from a group-randomized food pantry intervention in Minnesota. Methods: The CFNI was calculated for each client cart post-intervention (n = 187; 85 intervention, 102 control). CFNI scores were based on the proportion of items in each client cart ranked “green,” “yellow,” or “red” using the Healthy Eating Research Nutrition Guidelines for the Charitable Food System. An implementation score assessing intervention fidelity was measured for each pantry (n = 11; 5 intervention, 6 control) based on the four intervention subcomponents: aesthetics/use of space; healthy food prominence and appeal; unhealthy food de-emphasis; and stocking standards. Mixed linear models were used to test whether: (a) client carts from pantries in the intervention condition had higher CFNI scores than those in the control condition, and (b) higher implementation scores were associated with higher CFNI scores. Results: In adjusted models, clients from intervention group pantries had higher CFNI scores, reflecting a healthier assortment of foods compared with clients from control group pantries (p = 0.022). CFNI scores were positively associated with greater fidelity to the intervention (p = 0.020). Conclusions: The CFNI was sensitive enough to detect the effects of the intervention in the expected directions. These findings support its construct validity and utility as a measure in the charitable food system

Selective Daily Mobility Bias in the Community Food Environment: Case Study of Greater Hartford, Connecticut

The community food environment has potential influences on community members’ dietary health outcomes, such as obesity and Type II diabetes. However, most existing studies evaluating such health effects neglect human mobility. In food patrons’ daily travels, certain locations may be preferred and patronized more frequently than others. This behavioral uncertainty, known as the selective daily mobility bias (SDMB), is less explored in community-food-environment research. In this paper, we aim to confirm the existence of the SDMB by systematically exploring the large-scale GPS-based restaurant-visit patterns in the Greater Harford region, Connecticut. Next, we explore the restaurant and neighborhood characteristics that are associated with the restaurant-visit patterns. Our primary results demonstrate that (1) most restaurant customers originate from areas outside of the census tract where the restaurant is located, and (2) restaurants located in socially vulnerable areas attract more customers in total, more customers from local areas, and more customers from other socially vulnerable areas. These results confirm the relevance of the SDMB to the community food environment, and suggest ways that the SDMB can be moderated by an uneven socio-economic landscape. The findings demonstrate the necessity of incorporating human-mobility data into the study of the community food environment

Data to accompany Longitudinal Fruit and Vegetable Sales in Small Food Retailers: Response to a Novel Local Food Policy and Variation by Neighborhood Socioeconomic Status

The same data are provided in both .sas7bdat and .csv formats.Small food retailers, including corner/convenience stores, pharmacies, gas-marts, and dollar stores, have historically stocked limited fruits and vegetables, though this may be changing. We examined increases in sales, customer purchasing, and stocking of fresh and/or frozen fruits and vegetables in small food stores over time and in relation to: (a) a local food policy (the Minneapolis Staple Foods Ordinance) and (b) neighborhood socioeconomic status (SES). We used longitudinal data (2014–2017) from 147 randomly-sampled stores in Minneapolis/St. Paul, USA, collected using interviewer-administered manager surveys (measuring sales and stocking) and customer intercepts/ observations (measuring purchasing, n = 3039). The local policy required Minneapolis stores to meet minimum stocking standards for fresh/frozen produce and other healthy foods. No ordinance existed in St. Paul. Mixed regression models examined overall change over time and change by city and neighborhood SES. We observed significant increases over time (p < 0.05) in sales and purchasing of fresh fruit and in stocking of fresh fruit, frozen fruit, and frozen vegetables. We did not identify consistent statistical evidence for differential change in sales, purchasing, or stocking by city or neighborhood SES. Key study findings suggest limited differential effects of the local ordinance and/or neighborhood SES. However, findings also indicate significant time trends for some products, including consistent improvements in sales, customer purchasing, and stocking of fresh fruit. Given the ready-to-eat convenience of many fresh fruits and their broad appeal, fresh fruit appears a promising target for advancing the healthfulness of small food retailers.Sponsorship: National Institute of Diabetes and Digestive and Kidney Diseases (R01DK104348); Centers for Disease Control and Prevention (U48DP005022); National Institutes of Health (5R25CA163184); National Center for Advancing Translational Science (UL1TR000114); National Heart, Lung, and Blood Institute, grant number K99HL14482

Pricing of Staple Foods at Supermarkets versus Small Food Stores

Prices affect food purchase decisions, particularly in lower-income communities, where access to a range of food retailers (including supermarkets) is limited. The aim of this study was to examine differences in staple food pricing between small urban food stores and the closest supermarkets, as well as whether pricing differentials varied based on proximity between small stores and larger retailers. In 2014, prices were measured for 15 staple foods during store visits in 140 smaller stores (corner stores, gas-marts, dollar stores, and pharmacies) in Minneapolis/St. Paul, MN and their closest supermarket. Mixed models controlling for store type were used to estimate the average price differential between: (a) smaller stores and supermarkets; (b) isolated smaller stores (&gt;1 mile to closest supermarket) and non-isolated smaller stores; and (c) isolated smaller stores inside versus outside USDA-identified food deserts. On average, all items except white bread were 10–54% more expensive in smaller stores than in supermarkets (p &lt; 0.001). Prices were generally not significantly different in isolated stores compared with non-isolated stores for most items. Among isolated stores, there were no price differences inside versus outside food deserts. We conclude that smaller food stores have higher prices for most staple foods compared to their closest supermarket, regardless of proximity. More research is needed to examine staple food prices in different retail spaces

Longitudinal Fruit and Vegetable Sales in Small Food Retailers: Response to a Novel Local Food Policy and Variation by Neighborhood Socioeconomic Status

Small food retailers, including corner/convenience stores, pharmacies, gas-marts, and dollar stores, have historically stocked limited fruits and vegetables, though this may be changing. We examined increases in sales, customer purchasing, and stocking of fresh and/or frozen fruits and vegetables in small food stores over time and in relation to: (a) a local food policy (the Minneapolis Staple Foods Ordinance) and (b) neighborhood socioeconomic status (SES). We used longitudinal data (2014&ndash;2017) from 147 randomly-sampled stores in Minneapolis/St. Paul, USA, collected using interviewer-administered manager surveys (measuring sales and stocking) and customer intercepts/observations (measuring purchasing, n = 3039). The local policy required Minneapolis stores to meet minimum stocking standards for fresh/frozen produce and other healthy foods. No ordinance existed in St. Paul. Mixed regression models examined overall change over time and change by city and neighborhood SES. We observed significant increases over time (p &lt; 0.05) in sales and purchasing of fresh fruit and in stocking of fresh fruit, frozen fruit, and frozen vegetables. We did not identify consistent statistical evidence for differential change in sales, purchasing, or stocking by city or neighborhood SES. Key study findings suggest limited differential effects of the local ordinance and/or neighborhood SES. However, findings also indicate significant time trends for some products, including consistent improvements in sales, customer purchasing, and stocking of fresh fruit. Given the ready-to-eat convenience of many fresh fruits and their broad appeal, fresh fruit appears a promising target for advancing the healthfulness of small food retailers

Successful customer intercept interview recruitment outside small and midsize urban food retailers

Abstract Background Customer intercept interviews are increasingly used to characterize food purchases at retail food outlets and restaurants; however, methodological procedures, logistical issues and response rates using intercept methods are not well described in the food environment literature. The aims of this manuscript were to 1) describe the development and implementation of a customer intercept interview protocol in a large, NIH-funded study assessing food purchases in small and midsize food retailers in Minneapolis and St. Paul, Minnesota, 2) describe intercept interview response rates by store type and environmental factors (e.g., neighborhood socioeconomic status, day/time, weather), and 3) compare demographic characteristics (e.g., gender, race/ethnicity) of participants versus non-participants. Methods After a pilot phase involving 28 stores, a total of 616 interviews were collected from customers exiting 128 stores in fall 2014. The number of eligible customers encountered per hour (a measure of store traffic), participants successfully recruited per hour, and response rates were calculated overall and by store type, neighborhood socio-economic status, day and time of data collection, and weather. Response rates by store type, neighborhood socio-economic status, time and day of data collection, and weather, and characteristics of participants and non-participants were compared using chi-square tests. Results The overall response rate was 35 %, with significantly higher response rates at corner/small grocery stores (47 %) and dollar stores (46 %) compared to food-gas marts (32 %) and pharmacies (26 %), and for data collection between 4:00–6:00 pm on weekdays (40 %) compared to weekends (32 %). The distribution of race/ethnicity, but not gender, differed between participants and non-participants (p < 0.01), with greater participation rates among those identified as Black versus White. Conclusions Customer intercept interviews can be successfully used to recruit diverse samples of customers at small and midsize food retailers. Future community-based studies using customer intercept interviews should collect data sufficient to report response rates and consider potential differences between the racial/ethnic composition of the recruited sample and the target population

Validating a Nutrition Ranking System for Food Pantries Using the Healthy Eating Index-2015

In 2020, charitable food organizations began adopting Healthy Eating Research (HER) nutrition guidelines, which rank individual foods in tiers (e.g., green, yellow, or red) based on each food&rsquo;s nutrient profile. This study aimed to validate this HER tier-ranked system against the Healthy Eating Index-2015 (HEI) and develop a formula to summarize the percentages of tier-ranked foods in an overall nutritional quality index that correlated with HEI. Using secondary data of foods selected by clients in 16 Minnesota food pantries (n = 503 &ldquo;client carts&rdquo;), we generated an HEI score and percentages of green, yellow, and red foods for each cart. As validation, we tested the association between HEI scores and the percentages of tier-ranked foods and compared the means of the tier-ranked variables using quintiles of the HEI scores. HEI scores were positively associated with percentages of green foods and negatively associated with percentages of red foods. Next, we used statistical learning to generate weights to maximize the correlation of the tier-ranked variables and the HEI scores and used these weights to create an index. The index demonstrated a moderate-to-strong correlation with HEI and can be used as a single measure to summarize the overall nutritional quality for sets of tier-ranked foods

Association between store food environment and customer purchases in small grocery stores, gas-marts, pharmacies and dollar stores

Abstract Background Purchases at small/non-traditional food stores tend to have poor nutritional quality, and have been associated with poor health outcomes, including increased obesity risk The purpose of this study was to examine whether customers who shop at small/non-traditional food stores with more health promoting features make healthier purchases. Methods In a cross-sectional design, data collectors assessed store features in a sample of 99 small and non-traditional food stores not participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Minneapolis/St. Paul, MN in 2014. Customer intercept interviews (n = 594) collected purchase data from a bag check and demographics from a survey. Store measures included fruit/vegetable and whole grain availability, an overall Healthy Food Supply Score (HFSS), healthy food advertisements and in-store placement, and shelf space of key items. Customer nutritional measures were analyzed using Nutrient Databases System for Research (NDSR), and included the purchase of ≥1 serving of fruits/vegetables; ≥1 serving of whole grains; and overall Healthy Eating Index-2010 (HEI-2010) score for foods/beverages purchased. Associations between store and customer measures were estimated in multilevel linear and logistic regression models, controlling for customer characteristics and store type. Results Few customers purchased fruits and vegetables (8%) or whole grains (8%). In fully adjusted models, purchase HEI-2010 scores were associated with fruit/vegetable shelf space (p = 0.002) and the ratio of shelf space devoted to healthy vs. less healthy items (p = 0.0002). Offering ≥14 varieties of fruit/vegetables was associated with produce purchases (OR 3.9, 95% CI 1.2–12.3), as was having produce visible from the store entrance (OR 2.3 95% CI 1.0 to 5.8), but whole grain availability measures were not associated with whole grain purchases. Conclusions Strategies addressing both customer demand and the availability of healthy food may be necessary to improve customer purchases. Trial registration ClinialTrials.gov: NCT02774330 . Registered May 4, 2016 (retrospectively registered)

Data to accompany evaluation of the first U.S. staple foods ordinance: Impact on nutritional quality of food retailer offerings, customer purchases and home food environments

The same data are provided in both .sas7bdat and .csv formats.Many lower-income and racially diverse communities in the U.S. have limited access to healthy foods, with few supermarkets and many small convenience stores, which tend to stock limited quantities and varieties of healthy foods. To address food access, in 2015 the Minneapolis Staple Foods Ordinance became the first policy requiring food stores to stock minimum quantities and varieties of 10 categories of healthy foods/beverages, including fruits, vegetables, whole grains and other staples, through licensing. This study examined whether: (a) stores complied, (b) overall healthfulness of store environments improved, (c) healthy customer purchases increased, and (d) healthfulness of home food environments improved among frequent small store shoppers. Data for this natural (or quasi) experiment were collected at four times: pre-policy (2014), implementation only (no enforcement, 2015), enforcement initiation (2016) and continued monitoring (2017). In-person store assessments were conducted to evaluate food availability, price, quality, marketing and placement in randomly sampled food retailers in Minneapolis (n=84) and compared to those in a nearby control city, St. Paul, Minnesota (n=71). Stores were excluded that were: supermarkets, authorized through WIC (Special Supplemental Nutrition Program for Women, Infants, and Children), and specialty stores (e.g., spice shops). Customer intercept interviews were conducted with 3,039 customers exiting stores. Home visits, including administration of home food inventories, were conducted with a sub-sample of frequent shoppers (n=88). Overall, findings indicated significant improvements in healthy food offerings by retailers over time in both Minneapolis and St. Paul, with no significant differences in change between the two cities. Compliance was low; in 2017 only 10% of Minneapolis retailers in the sample were fully compliant, and 51% of participating Minneapolis retailers met at least 8 of the 10 required standards. Few changes were observed in the healthfulness of customer purchases or the healthfulness of home food environments among frequent shoppers, and changes were not different between cities. This study is the first evaluation of a local staple foods ordinance in the U.S. and reflects the challenges and time required for implementing such policies.National Institute of Diabetes and Digestive and Kidney Diseases (R01DK104348)Centers for Disease Control and Prevention (U48DP005022)Eunice Kennedy Shriver National Institute of Child Health and Human Development (U54HD070725)National Institutes of Health (5R25CA163184)National Center for Advancing Translational Science (UL1TR000114