Efficiency of In-Store Interventions to Impact Customers to Purchase Healthier Food and Beverage Products in Real-Life Grocery Stores: A Systematic Review and Meta-Analysis

Abstract

Grocery stores are important settings to promote healthier food and beverage choices. The present paper aims at reviewing the effectiveness of different types of in-store interventions and how they impact sales of different product category in real grocery stores. Systematic search was conducted in six databases. In-store interventions were categorized according to the framework by Kraak et al. (2017) into one or more of eight interventions (e.g., place, profile, portion, pricing, promotion, healthy default picks, prompting and proximity). This systematic theme-based review follows the preferred reporting items for systematic reviews and meta-analyses (PRISMA) data screening and selection. Thirty-six studies were included in the qualitative synthesis and 30 studies were included in the meta-analysis, representing 72 combinations of in-store interventions. The analysis demonstrates that interventions overall had small significant effect size (ES) using Cohen’s d on food purchase behavior (d = 0.17, 95% CI [0.04, 0.09]), with largest ES for pricing (d = 0.21) and targeting fruits and vegetables (d = 0.28). Analysis of ES of in-store interventions show that pricing, and pricing combined with promotion and prompting, effectively impacted purchase behavior. Interventions significantly impacted both sales of healthy and unhealthy products and significantly increased sales of fruits and vegetables, healthy beverage and total volume of healthy products. Results should however be interpreted with some caution, given the relatively low quality of overall evidence and low number of studies and observations for some types of intervention. Further research exploring impact on different in-store interventions and targeting especially unhealthy products are needed.

Limited implementation of California’s Healthy Default Beverage law for children’s meals sold online

“…Upcharges for the allowable default beverages are clearly contrary to the intent of SB1192 because the upcharges likely discourage those selections among price-conscious consumers. Prior evidence shows that pricing impacts beverage choice (30) , with studies conducted in stores demonstrating that cost, in combination with promotion and prompting, effectively impacts purchasing behaviour (31) . Price is an especially important factor for low-income consumers, who are significantly more conscious of cost and value than higher income consumers (38) .…”

“…Studies have found increased ordering of more healthful items (17,29) and reduced energetic intake (29) following the implementation of healthy default menus. Additional research indicates that cost also impacts beverage choice (30) , with in-store studies demonstrating that pricing, in combination with promotion and prompting, effectively impacts purchasing behaviour (31) . However, evidence regarding the impact of healthy default policies on pricing is mixed, with some studies finding price increases (29) and others reporting no change in prices (32,33) .…”

Impact on purchasing behaviour of implementing ‘junk free checkouts’: A pre‐post study

“…Relatively little research has examined the impact of removing less healthy foods from checkout areas on purchasing behaviour. Two recent systematic reviews reported that the majority of nudge interventions focused on in‐store promotions (for healthier foods), information provision, increased availability of healthier foods and, to a lesser extent, pricing (Adam & Jensen, 2016; Slapø et al, 2021). Nonetheless, the findings from these reviews are supportive of in‐store interventions being beneficial for diet‐related behaviours, although some caution is needed because of the lack of high‐quality studies.…”

Fixing America’s eating habits with effective stakeholder collaborations

“…Although adherence was somewhat sustained at 6 months, the results were not statistically significant at this timepoint. Previous research has shown similar short-term success in increasing fruits and vegetable consumption, but not long-term success 5 , and a meta-analysis of store-based diet interventions also showed mixed results 6 . However, the lack of sustained, long-term success up to now should not discourage us from delivering interventions at food retailers.…”