Abstract
Despite the considerable public and planetary health benefits associated with reducing the amount of meat consumed in high-income countries, there is a limited empirical understanding of how these voluntary changes in food choice can be effectively facilitated across different settings. While prior reviews have given us broad insights into the varying capacities of behavior change strategies to promote meaningful reductions in meat consumption, none have compared how they perform relative to each other within a uniform dining context. To address this gap in the literature, we synthesized the available research on university-implemented meat reduction interventions and examined the variations in the success rates and effect estimates associated with each of the three approaches identified in our systematic review. From our analyses of the 31 studies that met our criteria for inclusion (n = 31), we found that most were successful in reducing the amount of meat consumed within university settings. Moreover, independent of the number of individual strategies being used, multimodal interventions were found to be more reliable and effective in facilitating these changes in food choice than interventions targeting the choice architecture of the retail environment or conscious decision-making processes alone. In addition to demonstrating the overall value of behavior change initiatives in advancing more sustainable dining practices on college and university campuses, this study lends further insights into the merits and mechanics underlying strategically integrated approaches to dietary change. Further investigations exploring the persistence and generalizability of these effects and intervention design principles are needed.
Generated Summary
This meta-analysis and systematic review examined 31 dietary change interventions implemented across 24 universities over 21 years. The study aimed to assess the effectiveness of these interventions in reducing meat consumption within university settings and to compare the performance of three different approaches: targeting the choice architecture of the retail environment, targeting conscious decision-making processes, and multimodal interventions (which combined both). The research involved a meta-analysis of the success rates and effect estimates associated with each approach. The methodology included a comprehensive search strategy across seven electronic databases, rigorous selection criteria, quality assessment using the Evidence Project’s Risk of Bias Tool, and main analyses focused on success rates, effect estimates, and changes over time. The study’s scope was limited to interventions within higher education institutions (HEIs), focusing on their impact on meat consumption.
Key Findings & Statistics
- Of the 31 studies analyzed, the majority (67.7%) reported significant reductions in meat consumption.
- Multimodal interventions were associated with a 100% success rate in reducing meat consumption.
- Interventions targeting conscious decision-making processes showed a 56.3% success rate.
- Interventions targeting choice architecture showed a 40.0% success rate.
- Promotional messaging was the most common strategy, used in 80.6% of the interventions.
- Multimodal interventions reduced the overall odds of consuming meat by 187.5%.
- Interventions targeting conscious decision-making processes had a mean effect on meat consumption (OR = 1.68 [1.43, 2.05]).
- Interventions targeting the choice architecture of the retail environment had a greater mean effect on meat consumption (OR = 1.82 [1.57, 2.24]).
- The interventions reduced the overall odds of consuming meat within university settings by 81.8%.
- The studies were conducted between 2001 and 2021, with an exponential increase in publications over time.
- The studies were conducted in 33 different intervention sites spanning 24 colleges and universities across 9 countries.
- 51.6% of interventions targeted conscious decision-making processes while 48.4% targeted the choice architecture of the retail environment.
- Interventions that used promotional messaging were successful 57.1% of the time when used in isolation and 76.0% of the time when used in combination with other strategies (p = 0.029).
- When comparing multimodal interventions and unimodal interventions leveraging two or more strategies, multimodal interventions were associated with a higher rate of success (100%, compared to 50.0%) and a greater overall effect on food choice (OR = 2.88 [1.95, 4.64]), compared to (OR = 2.13 [1.64, 3.05]).
Other Important Findings
- Multimodal interventions were more reliable and effective in reducing meat consumption than interventions targeting either choice architecture or conscious decision-making processes alone.
- Interventions using at least two strategies concurrently were more likely to be associated with reductions in meat consumption than interventions using a single strategy in isolation (p = 0.024).
- Interventions that used promotional messaging strategies were particularly successful.
- The study found no significant differences in success rates between interventions conducted in Europe and North America (p = 0.28).
- The effect estimates associated with the included studies ranged from 17.97 [9.60, 33.63] to 0.61 [0.23, 1.58], with a mean standardized effect of 2.88 [1.85, 4.77], indicating that the included interventions reduced the overall odds of consuming meat within these settings by an average of 187.5%.
Limitations Noted in the Document
- The study’s evaluation periods were limited, making it impossible to assess the long-term effects of the interventions.
- The study could not evaluate potential rebound effects or contextual spillover.
- The findings’ generalizability is limited due to the geographic concentration of the studies (primarily in Europe and North America).
- The heterogeneity in the mean effect estimates associated with studies using self-reported measures of change compared to observational measures, could have affected the overall results.
- The study’s inability to assess the long-term effects, contextual spillover, and rebound effects.
Conclusion
This systematic review provides strong evidence supporting the effectiveness of university-implemented meat reduction interventions, particularly those that adopt a multimodal approach. The study’s findings indicate that combining strategies that target both the choice architecture of the retail environment and conscious decision-making processes yields the most favorable outcomes. This suggests that interventions should be designed to influence both implicit and explicit decision-making processes. The high success rate of interventions using promotional messaging highlights the importance of communication and education in driving dietary change. The study’s emphasis on the university setting is significant because it underscores the potential for institutional change to contribute to broader sustainability goals. As the study highlights, the research suggests that there may be inherent value in understanding how strategies can be integrated to exert influence on both implicit and deliberate decision-making processes. There is also an exponential increase in the amount of research that was conducted and published on university-implemented meat reduction interventions. However, the lack of improvement in intervention performance over time highlights a need for more setting-specific guidelines for interventions. The authors also note that the benefits of performance are a function of both the number of strategies used and the nature of how those strategies coalesce to exert influence on relevant decision-making processes. Future research should prioritize observational methods, extend evaluation periods, and examine the generalizability of these interventions across different cultural contexts and institutional settings. The study concludes that institutional stakeholders interested in promoting sustainable dining practices should consider incorporating multimodal design principles into future interventions.