BACKGROUND: The North Carolina (NC) Healthy Food Small Retailer Program (HFSRP) was passed into law with a $250,000 appropriation (2016-2018) providing up to $25,000 in funding to small food stores for equipment to stock healthier foods and beverages . This paper describes an observational natural experiment documenting the impact of the HFSRP on store food environments, customers' purchases and diets .
METHODS: Using store observations and intercept surveys from cross-sectional, convenience customer samples (1261 customers in 22 stores, 2017-2020; 499 customers in 7 HFSRP stores, and 762 customers in 15 Comparison stores), we examined differences between HFSRP and comparison stores regarding: (1) change in store-level availability, quality, and price of healthy foods/beverages; (2) change in healthfulness of observed food and beverage purchases (`` bag checks"); and, (3) change in self-reported and objectively-measured (Veggie Meter®-assessed skin carotenoids) customer dietary behaviors . Differences (HFSRP vs. comparison stores) in store-level Healthy Food Supply (HFS) and Healthy Eating Index-2010 scores were assessed using repeated measure ANOVA . Intervention effects on diet were assessed using difference-in-difference models including propensity scores .
RESULTS: There were improvements in store-level supply of healthier foods/beverages within 1 year of program implementation (0 vs. 1-12 month HFS scores; p = 0.055) among HFSRP stores only . Comparing 2019 to 2017 (baseline), HFSRP stores' HFS increased, but decreased in comparison stores (p = 0.031). Findings indicated a borderline significant effect of the intervention on self-reported fruit and vegetable intake (servings/day), though in the opposite direction expected, such that fruit and vegetable intake increased more among comparison store than HFSRP store customers (p = 0.05). There was no significant change in Veggie Meter®-assessed fruit and vegetable intake by customers shopping at the intervention versus comparison stores .
CONCLUSIONS: Despite improvement in healthy food availability, there was a lack of apparent impact on dietary behaviors related to the HFSRP, which could be due to intervention dose or inadequate statistical power due to the serial cross-sectional study design . It may also be that individuals buy most of their food at larger stores; thus, small store interventions may have limited impact on overall eating patterns . Future healthy retail policies should consider how to increase intervention dose to include more product marketing, consumer messaging, and technical assistance for store owners.
Index: Food desert, Food environment, Fruits and vegetables, Health policy, Healthy corner stores, Rural