Can healthy checkout counters in supermarkets promote healthier food choices? Two real-life experiments in supermarkets in a disadvantaged urban area in the Netherlands

Abstract

Background Most foods displayed at supermarket checkouts are unhealthy and do not support healthy purchases. This study investigates the sales effects of introducing healthier alternatives at supermarket checkouts. Methods We performed two real-life quasi-experimental studies in supermarkets located in a disadvantaged urban area in the Netherlands. In Study 1, we examined the impact of substituting healthier options for all the unhealthy snacks at checkouts (n = 1 supermarket). In Study 2, we investigated the impact of placing healthier snacks at checkouts (placement intervention), as well as the impact of offering a discount on healthier checkout snacks (placement + price intervention), while continuing to display unhealthy snacks for sale (n = 2 supermarkets). Supermarket sales data were used to measure purchases. Results In Study 1, median weekly sales/1000 customers of checkout snacks were 2.3 times lower (SE: 1.1, 95% CI: 1.9–2.7) during the intervention period – when healthier options were substituted for the entire unhealthy snack assortment – (median: 10, IQR: 2.8), as compared to the control period (median: 24, IQR: 2.8). In Study 2, median daily sales/1000 customers of healthier snacks were 2.1 times higher (SE: 1.3, 95% CI: 1.3–3.3) during the placement-intervention period (median: 7.8, IQR: 4.6), as compared to the control period (median: 4.2, IQR: 4.6). Similarly, median daily sales/1000 customers of healthier snacks were 2.7 times higher (SE: 1.2, 95%CI: 2.0–3.6) during the placement + price-intervention period (median: 5.8, IQR: 2.2), as compared to the control period (median: 2.2, IQR: 4.7). There was no difference between the effect of the placement intervention and that of the placement + price intervention (ratio: 1.1, SE: 1.3, 95% CI: 1.7–1.9). Neither did we observe a decline in purchases of unhealthy snacks (ratio: 1.3, SE: 1.1, 95% CI: 1.1–1.5). Conclusions This study showed that if we want to promote healthier food purchases at supermarket checkouts the substitution of the unhealthy snacks with healthier alternatives is an effective intervention, which is not the case if the unhealthy snacks remain in place at the checkouts, even with discounts on the healthier snacks. Future research should assess the feasibility and willingness of eliminating unhealthy checkout snacks in supermarkets.