A reversal of defaults: Implementing a menu-based default nudge to promote out-of-home consumer adoption of plant-based meat alternatives

Changing the default meal option at university events to reduce harmful environmental impacts: Six randomized controlled trials

Animal agriculture is a leading contributor to greenhouse gas emissions and other harmful environmental impacts, which underscores the need to shift away from the consumption of animal-based products. One promising nudge intervention is making plant-based meals the default option, so we tested this approach at six different university events across four academic institutions for effecting sustainable dietary change. Event attendees pre-selected their meal on one of two randomly assigned RSVP forms: one with a plant-based default and one with a meal with meat default. The results from our randomized controlled trial showed that participants had a 43-percentage point greater probability of selecting the plant-based meal when it was indicated as the default option. This effect was similar across events and academic institutions, which indicates that this default intervention is generalizable and can be successfully implemented at university events. The combined effect of using plant-based defaults at these six events was an estimated reduction of 104,387 kg of CO2 emissions, 299.9 m2 of land use, 959.0 g of nitrogen use, and 259.5 g of phosphorus use, which represent roughly 45-46.2% reductions in harmful environmental impacts relative to the meals chosen when using a meat default. Given the significance and magnitude of these environmental benefits, our results support the widespread implementation of plant-based defaults for helping universities improve their sustainability.

Promoting plant-based eating in meat-centric meal contexts: a field study

OBJECTIVE

Shifting from meat-centric to plant-rich diets may help to enable healthier and more sustainable food systems. Here we present the results of a 1-week intervention to promote plant-based eating in a meat-centric food context (i.e. canteen).

DESIGN

The intervention included environmental restructuring strategies (e.g. promotional materials and menu redevelopment) and improvements to the offer of plant-based meals. The evaluation (sales data; pre-registered) spanned 3 weeks prior to the intervention (baseline), 1 week during the intervention (immediate/short-term impact) and 3 weeks after the intervention (follow-up). Opinion surveys were also used to collect data with customers during the intervention.

SETTING

Canteen unit of a university campus in Portugal (Lisbon metropolitan area).

PARTICIPANTS

In addition to sales data (baseline: 7965 meals; immediate/short-term: 2635 meals; follow-up: 7135 meals), we used opinion surveys to assess customers' meal appraisals during the intervention (n = 370).

RESULTS

The odds of a sold meal being vegetarian were 24 % higher in the intervention week compared with the pre-intervention period [OR = 1·24, 95 % CI (1·10, 1·40)] and 9 % higher in the post-intervention period compared with the pre-intervention period [OR = 1·09, (95 % CI (1·00, 1·19)]. Survey data showed that vegetarian meals compared favourably to meat and fish alternatives in liking, sustainability and satiety.

CONCLUSIONS

A short-term, theory-driven, operationally feasible intervention was effective in promoting increased plant-based meal choices in a collective meal context. Nevertheless, these changes were not entirely sustained over time. Future studies could test whether prolonged or more transformative interventions are necessary to unlock entrenched food practices more effectively in meat-centric collective meal contexts.

How do defaults and framing influence food choice? An intervention aimed at promoting plant-based choice in online menus

Nudging consumers towards plant-based foods by making these choices the default option is a promising strategy for effecting sustainable dietary change. In the hypothetical context of online food ordering in a Northern European country, we examined the underlying mechanisms and effectiveness of swapping the default in menus from meat to a plant-based meat alternative. Results showed that pre-selecting a plant-based option in the online setting was not enough to increase choice of plant-based meals alone. Rather, additionally framing the plant-based default as the more sustainable or tasty option was needed to significantly increase choice. While ease was unimportant and held constant in this online setting, endowment and implied endorsement were found to mediate default success such that the positive influence of endowment outweighed the (surprising) negative effect via endorsement. In contrast to general theoretical expectations of default nudges, an endorsement by an online food provider is unlikely to encourage plant-based choices.

The negative impact of vegetarian and vegan labels: Results from randomized controlled experiments with US consumers

Reducing consumption of animal products is a critically important challenge in efforts to mitigate the climate crisis. Despite this, meals containing animal products are often presented as the default versus more environmentally sustainable vegetarian or vegan options. We tested whether vegetarian and vegan labels on menu items negatively impact the likelihood of US consumers choosing these items by using a between-subjects experimental design, where participants chose a preference between two items. Menu items were presented with titles and descriptions typical at restaurants, and a random group saw "vegan" or "vegetarian" labels in the titles of one of the two items. Two field studies were conducted at a US academic institution, where people selected what to eat via event registration forms. The methodology was extended to an online study, where US consumers selected what to hypothetically eat in a series of choice questions. Overall, results showed the menu items were significantly less likely to be chosen when they were labeled, with much larger effects in the field studies, where choice was not hypothetical. In addition, the online study showed male participants had a significantly higher preference for options containing meat versus other participants. Results did not indicate the impact of labels differed by gender. Furthermore, this study did not find that vegetarians and vegans were more likely to choose items with meat when the labels were removed, indicating that removing labels did not negatively impact them. The results suggest removing vegetarian and vegan labels from menus could help guide US consumers towards reduced consumption of animal products.

Prospects for Plant-Based Meat: Current Standing, Consumer Perceptions, and Shifting Trends

Dietary habits have a substantial influence on both planet and individual health. High intake of animal products has significant negative effects on the environment and on human health; hence, a reduction in meat consumption is necessary. The transition towards plant-based meat (PBM) is one of the potential solutions for environmental and health issues. To achieve this goal, it is important to understand the dietary habits and demands of consumers. This review was designed with a focus on PBM alternatives, dietary shifts during the COVID-19 pandemic, the drivers of consumers' perceptions in various countries, and the measures that can promote the shift towards PBM. The PBM market is predicted to grow with rising awareness, familiarity, and knowledge in the coming years. Companies must focus on the categories of anticipated benefits to aid consumers in making the switch to a diet higher in PBM alternatives if they want to win over the target market.

Social Norms Support the Protein Transition: The Relevance of Social Norms to Explain Increased Acceptance of Alternative Protein Burgers over 5 Years

Developing alternative protein products-based on protein sources other than regular meat-is a possible pathway to counter environmental and health burdens. However, alternative proteins are not always accepted by consumers, and more research is needed to support a shift to more alternative proteins. Prior studies have mainly focused on individual drivers and perceptions; although we expect that social norms-the perceptions of the opinions of relevant others-are highly relevant in accepting alternative proteins. Online surveys were conducted among 2461 respondents in 2015 and 2000 respondents in 2019 (cross-sectional datasets); a subsample (n = 500) responded to both surveys (longitudinal dataset). We add to the literature by (1) demonstrating the added explanatory value of social norms beyond a range of individual drivers; (2) showing that this finding holds over time, and (3) comparing the impact of social norms across different dietary consumer groups. Meat lovers and flexitarians are more prone to follow social norms whereas meat abstainers are more prone to follow their individual attitudes and values. This study highlights the relevance of investigations beyond personal variables such as personal norms and attitudes and underscores the relevance of considering the social aspects of accepting alternative proteins.