Simple Eco-Labels to Nudge Customers Toward the Most Environmentally Friendly Warm Dishes: An Empirical Study in a Cafeteria Setting

Abstract

Background: Food production and consumption contributes to one third of households' environmental impact. The environmental impact of different food categories varies and in general environmental footprint of meat is high than fish and vegetable options. Environmental food labels have been suggested as a means to sway consumption patterns. The purpose of this study is to test if different simple eco-labels in combination with posters can influence consumers to select environmentally friendly food options. Method:Three different labeling systems were tested on warm dishes in a University cafeteria in Oslo, Norway. The first system was traffic-light labels with three symbols (red, yellow and green), the second system was a single-green label that only labeled the environmentally friendliest dishes, and the third system was a single-red label that only labeled the least environmentally friendly option. Posters were placed in the cafeteria, explaining the labeling systems and the climate impact of different food categories. Outcome measures was sales share of meat, fish and vegetarian dishes. The intervention period was separated in two; the first 20 days (period 1) and 22 last days (period 2) to evaluate if the effects of the labels was different when first introduced and after some months. Results:The traffic-light labels significantly reduced sales of meat dishes with 9% in the period 1 (p < 0.1) but not in period 2. Sales share of fish or vegetarian dishes were not impacted. Single-green and single-red labeling had no effect on sales share of meat, fish or vegetarian dishes. Posters were present during all interventions.Conclusion: Findings suggests that traffic-light labels in combination with posters can improve the eco-friendliness of customers food choices in a cafeteria setting, at least short-term. Future studies should investigate the long-term effects of simple eco-labels. Additionally, one should study the combined effect of symbols with other changes in the choice architecture.

Nudging interventions on sustainable food consumption: a systematic review

“…The studies utilising nudges SA (Gravert and Kurz, 2019;Kurz, 2018), P (Garnett et al, 2019), D/P combination (Coucke et al, 2019;Vandenbroele et al, 2018) and D/SA combination (Campbell-Arvai et al, 2014) provided statistically significant impact for increasing sustainable food choices. However, studies that implemented D (Zhou et al, 2019), P/SA combination (McBey et al, 2019) and SA (Piester et al, 2020;Salmivaara and Lankoski, 2019;Slapø and Karevold, 2019) were not statistically significant. One study which utilised P/SA combination (Ohlhausen and Langen, 2020) showed statistical significance with regards to SA but not P, whilst a P/SA combination (Kaljonen et al, 2020) and I/MN/SA combination (Becchetti et al, 2020) illustrated marginal statistical significance, highlighting the potential use of these combinations.…”

“…Weekly sales of vegetarian dishes increased by 0.8%-0.9% after the intervention ceased (p ≤ 0.01) (Kurz, 2018). Slapø and Karevold (2019) found that impementing traffic light labelling (red, yellow, green) on dishes to indicate the environmental friendliness of a dish, encouraged a 7%-9% reduction in meat sales (p=0.10), although having just singular green or red labels had little to no impact (p>0.1). Salmivaara and Lankoski (2019) indicated that activating injunctive norm message signs at point of purchase had no significant effect on sustainable food choice (p=0.6263), whilst Piester et al (2020) found that implementing sustainability labels on menus marginally influenced women's uptake of more sustainable choices (p=0.11) but not for men (p=0.23).…”

“…In total, five of the studies utilised the nudge SA to encourage SFC (Kurz, 2018;Gravert and Kurz, 2019;Salmivaara and Lankoski, 2019;Slapø and Karevold, 2019;Piester et al, 2020). The main strategy utilised consisted of signage, ranging from descriptive menus to visual environmental information.…”

“…Piester et al (2020) highlighted that only 45% of participants purchased what they intended, hence the intention-behaviour gap of consumers is crucial in understand purchasing habits (ElHaffar et al, 2020;Rausch and Kopplin, 2021). Slapø and Karevold (2019) provided marginally significant results utilising traffic light labelling, supporting the theory of the 'compromise effect' (choosing the middle option) (Carroll and Vallen, 2014). Initially there was 7-9% reduction in meat consumption (p=0.10), this behaviour declined over time and almost reverted back to the control period behaviour after period 1; providing evidence that consumers can develop "label fatigue" (p=0.38) (Thorndike et al, 2014).…”

Impact of a College Course on the Sustainability of Student Diets in Terms of the Planetary Boundaries for Climate Change and Land, Water, Nitrogen and Phosphorus Use

“…Among studies addressing information-only interventions, results were mixed. While traffic light labeling reduced meat sales in one study, it did not for a second study (Slapo and Karevold, 2019). Two studies showed that informational messaging reduced food waste by 15% (Whitehair, 2013;Pinto et al, 2018), while another study showed simply providing information didn't significantly impact the support for initiatives to reduce meat (De Groeve and Bleys, 2017).…”