Abstract
Meat-based food production has a detrimental impact on the environment and health. In response, Veganuary (an international non-profit organisation) encourages people to go vegan each January. We investigated the effects of a Veganuary campaign in workplace cafeterias which increased the availability and salience of plant-based products. We conducted an interrupted time series analysis on a large dataset from a UK catering company, which comprised 2,255,404 meals sold between 2016 and 2022, with Veganuary activity starting from 2019. Analysis indicated that Veganuary activity had a positive effect on sales of vegan products in 2020, 2021 and 2022, estimated at an initial increase of 86–113% in the proportion of weekly sales (relative to the baseline, depending on year). The effects of the 2020 and 2021 campaigns were still present – at approximately one-third of their initial magnitude – one year following the campaigns. There was a positive effect on vegetarian products in 2019, 2021 and 2022; initial effects were smaller – 23–79% due to higher levels of pre-campaign consumption. The effects of the 2019 and 2021 campaigns endured, with a small impact present after one year for 2019 and six months for 2021.
Generated Summary
This study investigates the impact of the Veganuary campaign on consumer choices in workplace cafeterias, utilizing an interrupted time series analysis. The research focuses on the effect of increased availability and prominence of plant-based products within the cafeterias of a large UK catering company. The methodology involves analyzing sales data from 2016 to 2022, with the Veganuary campaign implemented annually from 2019. The primary aim is to evaluate the short- and medium-term effectiveness of the campaign on the sales of vegan and vegetarian meals. The study employs Autoregressive Integrated Moving Average (ARIMA) intervention analysis to assess the impact of the campaign periods on the proportion of vegan and vegetarian sales, considering the underlying trends and seasonal variations. The research seeks to determine the influence of the campaign on dietary choices, offering insights into the potential of such interventions in promoting sustainable diets.
Key Findings & Statistics
- Meat-based food production’s impact: Approximately one-third of global greenhouse gas emissions (GHGs) are by-products of food production processes.
- Animal-source foods: On average, have a greater environmental impact than plant-based foods.
- Impact of meat production: Approximately 60% of food-related GHGs are a direct result of the production of meat-based products.
- Vegan products in baseline: 2.62% (N = 25/955) of products.
- Vegan products in 2020 campaign: 2.97% (N = 27/901).
- Vegan products in 2021 campaign: 6.77% (N = 61/896).
- Vegan products in 2022 campaign: 5.24% (N = 40/759).
- Vegetarian products in baseline: 19.79% (N = 188/955) of products.
- Vegetarian products in 2021 campaign: 24.08% (N = 216/896).
- Vegetarian products in 2022 campaign: 23.87% (N = 182/759).
- Campaign Effect in 2020: The initial increase in the proportion of weekly sales of vegan products was estimated at 86-113% (relative to baseline).
- 2020 vegan campaign impact: translated into extra sales of approximately 107 vegan meals per week.
- Campaign effect in 2021: The initial increase in the proportion of weekly sales of vegan products was estimated at 86-113% (relative to baseline).
- 2021 vegan campaign impact: translated into extra sales of approximately 190 vegan meals per week.
- Campaign effect in 2022: The initial increase in the proportion of weekly sales of vegan products was estimated at 86-113% (relative to baseline).
- 2022 vegan campaign impact: translated into extra sales of approximately 181 vegan meals per week.
- 2019 vegetarian sales increase: Initial increase of 23–79% (relative to baseline).
- 2021 vegetarian sales increase: Initial increase of 23–79% (relative to baseline).
- 2022 vegetarian sales increase: Initial increase of 23–79% (relative to baseline).
- Vegan Sales in 2021 and 2022: 3.02% and 3.14%, respectively.
- Average Cost: Consumers on average paid £2.56 for a vegan meal and £2.40 for a vegetarian meal.
Other Important Findings
- The Veganuary promotion increased the proportion of vegan meals sold during the annual campaign periods.
- The Veganuary promotion increased the proportion of vegetarian meals sold during the annual campaign periods.
- The effects of the 2020 and 2021 campaigns were still present at approximately one-third of their initial magnitude one year following the campaigns.
- The effects of the 2019 and 2021 campaigns endured, with a small impact present after one year for 2019 and six months for 2021.
- Statistically significant campaign effects were observed for the 2020, 2021, and 2022 campaigns.
- The low proportion of vegan sales in the baseline period (1.86%, SD = 0.714%), the sizes of the initial effects were large – almost doubling the baseline level.
- The ARIMA intervention model highlighted statistically significant campaign effects for the 2019, 2021 and 2022 campaign periods.
- The 2022 campaign period had a much larger initial effect compared to previous years – peaking at a 9.7 percentage point increase in vegetarian product sales.
- The effects of the campaigns often endured.
- The study suggests that a Veganuary campaign – which involves increasing the availability of plant-based options on a menu and promoting them – can have a sustained impact on behaviour.
Limitations Noted in the Document
- Selection Bias: The exclusion procedure could have led to selection bias in the set of workplace cafeterias included in the final dataset.
- Generalizability: The extent to which the results may be generalized remains unclear.
- Fidelity of Implementation: Limited information was available about the details of the annual campaign activities and the fidelity of the implementation of the campaign activities across the cafeterias.
- COVID-19 Impact: Total footfall and sales may have been lower during the COVID period.
- Statistical Power: The 2022 time series was also much shorter than those for 2019, 2020 and 2021: there were fewer than 50 time points for this year, thereby reducing our statistical power and ability to precisely estimate the decay shape.
Conclusion
This study provides valuable insights into the effectiveness of the Veganuary campaign in promoting plant-based meal choices within workplace cafeterias. The research demonstrates a consistent positive impact on both vegan and vegetarian product sales across the cafeterias, although the magnitude of the effect varied across different years. The campaign’s influence was particularly notable in 2020, 2021, and 2022, with significant increases in the proportion of vegan products sold. The study’s findings indicate that the intervention had a lasting effect, with impacts extending beyond the immediate campaign periods. The observed initial effects were substantial, and the proportional increases in vegan product sales were significant relative to the baseline levels. The research highlights the potential of interventions that enhance the availability and prominence of plant-based options in cafeteria menus. Such approaches appear effective in promoting dietary changes. The study underscores the relevance of social marketing initiatives in encouraging plant-based diets and underscores the significance of availability as a key factor. The study’s insights align with previous research, suggesting that promoting plant-based options can lead to enduring increases in sales. These results suggest that increasing the availability of vegan and vegetarian items in cafeteria menus can have an ongoing positive impact on sales. The study also suggests that the intervention investigated is relatively low-cost and straightforward to implement compared to other interventions, which may play an important role in accelerating the widespread adoption of sustainable diets. The study’s findings contribute to the growing body of evidence supporting the effectiveness of interventions aimed at promoting plant-based food choices and the potential of such initiatives to contribute to both individual health and environmental sustainability.