Impact of food swap recommendations on dietary choices in an online supermarket: A randomized controlled trial

Abstract

One novel strategy to shift food choices in digital shopping environments is to automatically recommend healthier alternatives when an unhealthy choice is made. However, this raises the question which alternative products to recommend. This study assesses 1) whether healthier food swap recommendations are effective, even though the unhealthy choice was made in the presence of visible FOP nutrition labels, and 2) how the similarity of the alternatives influences the acceptance of food swap recommendations. Based on a pre-test, similarity of the recommendation was operationalized in terms of animal-based versus plant-based options. A randomized controlled trial (healthy food swap recommendation conditions: none, similar animal-based, dissimilar plant-based, or mixed animal- and plant-based) with 428 Dutch participants was conducted in a simulated online supermarket. Additional healthier food swap recommendations improved the nutritional quality of the final basket compared to only providing Nutri-Score nutrition labels (-1.7 mean FSA score, p < .001, medium Cohen's d = -0.48). Compared to the dissimilar condition, acceptance of an alternative was more likely in the mixed (odds-ratio = 2.78, p = .015) and in the similar condition (odds-ratio = 2.24, p = .048), but the nutritional quality of the final basket did not differ between treatment conditions. Individuals in treatment conditions who did not receive any recommendation (i.e. only made healthy choices) had higher Nutri-Score familiarity and general health interest than individuals who received recommendations. This suggests that for individuals with higher knowledge and motivation FOP nutrition labels were sufficient, whereas for individuals with lower knowledge and motivation additional food swap recommendations can improve dietary choices. Food swap recommendations may act as meaningful reminders by disrupting the automatic choice process and triggering individuals to rethink their (unhealthy) choice.

Keywords: Food swap; Front-of-pack label; Healthy food choice; Nutrition label; Plant-based food; Supermarket.