Abstract
This study investigates a simple, generic and easily scalable nudge to promote healthy and sustainable food choices at conferences by using a vegetarian lunch-default as a normative signal. Methods At three conferences, participants registering electronically were randomized into two groups: Group 1 received a standard lunch registration presenting a non-vegetarian buffet as the default, but allowing the active choice of a vegetarian option; Group 2 received a registration presenting a vegetarian buffet as the default, allowing the active choice of a non-vegetarian option. The study also assessed gender differences for two of the conferences and the participants’ acceptance of the nudge at one of the conferences. Results In experiment A the vegetarian choice increased from 2% to 87% (N = 108, P < 0.001). In experiment B it increased from 6% to 86% (N = 112, P < 0.001). In experiment C it increased from 12.5% to 89% (N = 110, P < 0.001). A significant tendency for men, but not women, to opt out of the vegetarian default was found and a clear majority of participants reported positive attitudes toward the nudge. Conclusions Changing the lunch-default to a vegetarian option is an effective, generic, easy to scale and well-accepted nudge to promote healthy and sustainable food choices at conferences.
Generated Summary
This study investigates the effectiveness of a simple, generic, and easily scalable nudge to promote healthy and sustainable food choices at conferences. The research employs three randomized controlled field experiments, utilizing a vegetarian lunch-default as a normative signal within electronic conference registration forms. Participants were randomly assigned to groups with either a standard lunch registration (non-vegetarian default with a vegetarian option) or a vegetarian lunch registration (vegetarian default with a non-vegetarian option). The study assesses gender differences and participant acceptance of the nudge. The methodological approach involves high external and ecological validity, with natural collection of background variables and easy replicability. The theoretical perspective considers changes in defaults as a robust strategy for influencing choices. The primary aim is to determine if changing the lunch-default to a vegetarian option can effectively encourage healthier and more sustainable food choices in conference settings.
Key Findings & Statistics
- Experiment A: In Experiment A, the vegetarian choice increased from 2% to 87% (N = 108, P < 0.001).
- Experiment B: In Experiment B, the vegetarian choice increased from 6% to 86% (N = 112, P < 0.001).
- Experiment C: In Experiment C, the vegetarian choice increased from 12.5% to 89% (N = 110, P < 0.001).
- Meat Production Impact: Meat production and consumption have been linked to dying prematurely and are a central source of CO2 emissions, responsible for ~15% of total global CO2 emissions.
- Meat Consumption and Mortality: A 2012 study found that the consumption of red meat increased the risk of dying prematurely.
- Dietary CO2 Emissions: A 2014 study showed that meat-rich diets resulted in 7.2 kg CO2 emissions per day, low meat diets 4.7 kg CO2 emissions per day, vegetarian and fish-eating diets caused ~3.8 kg CO2 emission per day, and vegan diets were responsible for ~2.9 kg CO2 per day.
- Experiment A: In Group 1, 2% chose the vegetarian option, while in Group 2, 87% chose the vegetarian option.
- Experiment B: In Group 1, 6% chose the vegetarian option, while in Group 2, 86% chose the vegetarian option.
- Gender Differences in Experiment B: In Group 1, 6% of women chose the vegetarian option, while in Group 2, 96% chose the vegetarian option. In Group 1, 8% of men chose the vegetarian option, while in Group 2, 68% chose the vegetarian option.
- Gender Differences in Experiment C: In Group 1, 12.5% chose the vegetarian option, while in Group 2, 89% chose the vegetarian option.
- Approval Rate of Nudge: The overall approval rate of the nudge was 85%.
- Gender and Deviation from Default: Men had a significantly higher tendency to deviate from the vegetarian default option (P = 0.032 in Experiment B and P = 0.002 in Experiment C).
Other Important Findings
- The study’s focus is on out-of-home settings, which are known to enable generic interventions.
- Defaults are a particularly robust strategy for influencing choices.
- The assumption is that a vegetarian lunch-default may signal what behavior is preferred by conference organizers.
- Experiment B collected gender data, with significant gender differences noted.
- Participants generally approved of the nudge.
- Men showed a higher tendency to deviate from the vegetarian default.
- The intervention is effective, robust, and generic in influencing food choices.
Limitations Noted in the Document
- The study included only 330 food choices across three experiments.
- Generalizing results may be limited due to the specific settings and participants.
- External validity could be improved by increasing the number of conferences, and the diversity of participants.
- The study was conducted in Denmark with primarily Danish participants.
- Data collection could be improved to gain more detail about potential individual and social variances.
- The study acknowledges the potential for different results in contexts outside of Denmark or with varied educational levels.
Conclusion
The study demonstrates that changing the default option to a vegetarian choice in electronic conference registration forms significantly influences food choices in a widespread eating-out-of-home setting. The findings suggest that this simple intervention can promote healthy and sustainable food choices at conferences. The high approval rate of the nudge indicates that participants generally accept the intervention. The gender-based differences observed suggest that the intervention’s effectiveness may vary depending on the audience. The study underscores the importance of considering non-rational social and contextual factors in influencing food decisions. This study provides evidence to stakeholders when they face uncertainty about the likely reaction of conference participants if they consider changing the default of their registration forms. This research aligns with the growing recognition of the link between meat consumption and negative health and environmental impacts. The study’s results contribute to the literature on nudges by identifying a robust and generic intervention that can be applied in settings known to facilitate large-scale changes in behavior. The findings support the idea that interventions targeting food choices in specific contexts can be an effective component of broader efforts to promote sustainability. “In line with theoretical predictions, simply changing the default consistently and significantly influenced conference participants’ food choices.”