A diet-related health prompt with the Swiss Food Pyramid as a nudge to reduce meat consumption

High meat consumption in Western societies is a major contributor to climate change, environmental damage, and health costs. One way to reduce meat consumption is through nudges in staff restaurants. Though previous studies have shown that nudges can influence consumer choices, there is a lack of comparative studies of the different types of nudges in the context of staff restaurants. The present study thus aimed to compare, individually and in combination, the effectiveness of a written prompt, a visual prompt (the Swiss Food Pyramid), and a dynamic social norm in encouraging consumers to more frequently choose meatless menu options. A 1 × 8 between-subjects design was applied, and an online choice experiment (n = 2198) was conducted, where the participants chose 15 times between a meat menu, a vegetarian menu, and a salad buffet. The participants who encountered the written prompt combined with the visual prompt chose the meatless option more often than those in the control condition. The written prompt contributed most to the intervention’s effectiveness. Although the effect size was small, this intervention combination is worth testing in the field, as it proved effective for all participants regardless of their psychological characteristics.