Abstract
Background: There is increasing consensus that transitioning towards reduced meat consumption and more plant-based diets is a key feature to address important health and sustainability challenges. However, relevant evidence that may inform these transitions remains fragmented with no overarching rationale or theoretical framework, which limits the ability to design and deliver coordinated efforts to address these challenges. Scope and approach: Eleven databases were systematically searched using sets of keywords referring meat curtailment, meat substitution and plant-based diets, as well as consumer choice, appraisal or behavior (2602 articles selected for title and abstract screening; 161 full-texts assessed for eligibility; 110 articles selected for extraction and coding). Barriers and enablers were identified and integrated into an overarching framework (i.e., COM-B system), which conceptualizes behavior as being influenced by three broad components: capability, opportunity and motivation. Key findings and conclusions: This review mapped potential barriers and enablers in terms of capability, opportunity, and motivation to reduce meat consumption and follow more plant-based diets. These included lack of information for consumers and difficulty to acquire new cooking skills (barrier, capability), changes in service provision in collective meal contexts (enabler, opportunity), and positive taste expectations for plant-based meals (enabler, motivation). Evidence on variables referring to the motivation domain is clearly increasing, but there is a striking need for studies that include capability and opportunity variables as well. The results of this review are relevant to a variety of fields and audiences interested in promoting sustainable living and health improvements through dietary choice.
Generated Summary
This review article, published in “Trends in Food Science & Technology,” employs a systematic search across eleven databases to examine the current evidence and future directions concerning the reduction of meat consumption and the adoption of plant-based diets. The research aims to address the fragmented nature of existing evidence by integrating findings into an overarching theoretical framework, specifically the COM-B (Capability, Opportunity, Motivation – Behavior) system, which conceptualizes behavior change as influenced by these three components. The methodology involves screening a large number of articles, assessing full texts for eligibility, and extracting data for qualitative synthesis. The primary focus is on identifying barriers and enablers related to meat curtailment, meat substitution, and plant-based diets, with the goal of informing future research and interventions promoting sustainable living and health improvements through dietary choices.
Key Findings & Statistics
- A total of 2602 articles were initially selected for title and abstract screening.
- 161 full-texts were assessed for eligibility.
- 110 articles were selected for extraction and coding.
- The majority of studies (81%) reported studies with a uniquely quantitative design.
- 73% of which used cross-sectional surveys and 21.3% of which were experiments or randomized control trials.
- 3.6% reported studies with a mixed design using qualitative and quantitative methodological triangulation.
- Samples ranged from eight to 63808 participants (M = 2011; SD = 7481; Q1 = 112, Q2 = 293, Q3 = 1017).
- 57.3% were relatively balanced in terms of gender (~50/50), 37.1% were markedly biased towards female participants (> 60/40) and 5.6% were markedly biased towards male participants (> 60/40).
- The large majority of studies (70%) did not specify a main theoretical framework.
- The studies reported findings for variables referring to meat reduction (61%), plant-based diets (38.2%), and/or plant-based meals and food products (22.7%).
- The very large majority of studies addressed variables that were framed in the motivation domain (93.6%), and a smaller proportion addressed opportunity (20%) and/or capability variables (6.4%).
- Studies published before the year 2000, represent a small proportion of the articles (5.4%).
- Most of the articles (81%) reported studies with a uniquely quantitative design.
- The majority of the studies included in the review (68.2%) were published between 2013 and 2018, which shows the increasing research interest on this topic.
- Higher prices of meat were identified as triggers to reducing or avoiding meat consumption.
- Beef E.coli recalls were found to significantly reduce consumer demand for beef products.
- Protein supplies (i.e. plant protein and meat protein) differed across countries based on geographical location and GDP.
Other Important Findings
- Male gender was consistently associated with increased meat consumption and unwillingness to eat more plant-based diets, whereas the female gender was usually associated with lower meat consumption and with being more open to eat plant-based meals and follow plant-based diets.
- Younger participants tended to be more positive towards plant-based meals and plant-based diets.
- Higher education and higher SES were enablers for following more plant-based diets.
- Consumers who reported following plant-based diets were also more likely from urban areas.
- Difficulty in acquiring new skills and competencies are barriers to reducing meat consumption and eating more plant-based diets.
- Social representations of meat as the center of the plate, social prejudice towards consumers following plant-based diets, unwillingness and reactance from close others, and lack of social support were identified as barriers.
- Willingness and supportiveness from close others, meat recalls and increased prices of meat products, perceived dynamic norms, and changes in service provision in collective meal contexts were identified as facilitators.
- Perceived lack of responsibility to change, licensing arguments, lack of environmental concern, meat attachment, and lack of familiarity and negative appraisal of meat substitutes/plant-based meals are also barriers.
- Interest in healthier and/or sustainable eating habits, general health and environmental consciousness, familiarity and favorable attitudes towards meat substitutes, and positive outcome expectancies (e.g., taste) were identified as facilitators.
- Perceived self-efficacy and behavioral control were also identified as predictors of willingness and intentions to reduce meat consumption and follow plant-based diets.
- Communicating the risks of meat consumption with affective and moral concerns decreased the acceptability of these risks, and increased intentions to reduce meat consumption.
- Perceiving materials that advocated for plant-based diets as more autonomy-supportive (vs. controlling) was associated with increased intentions to reduce meat consumption and eat more plant-based meals.
Limitations Noted in the Document
- The research on shifting from meat-based to increasingly plant-based diets should not necessarily disregard other theoretical frameworks in favor of the COM-B model.
- The review did not cover all the available research on topics relevant for a shift from meat-based to increasingly plant-based diets.
- The focus was not on performing an in-depth analysis of all the articles that were included in the qualitative synthesis.
- The COM-B system is not yet used in the focal topic.
- The large majority of the findings captured in this review were from observation or cross-sectional studies.
Conclusion
The review’s primary contribution lies in mapping barriers and facilitators related to meat curtailment and plant-based diets within the COM-B framework, which categorizes these factors into capability, opportunity, and motivation. The study underscores the critical role of motivation, with a wealth of existing research, while highlighting the need for more studies addressing capability and opportunity factors. The identified barriers encompass practical challenges like acquiring new cooking skills, social pressures related to meat consumption, and individual attitudes. Conversely, facilitators include positive taste expectations for plant-based meals, supportive social environments, and awareness of health and sustainability. The article emphasizes the importance of interventions that target these various components to effectively promote dietary transitions. It recommends that future research focus on experimental and longitudinal studies to better understand the dynamic interplay between capability, opportunity, and motivation. This integrated approach is crucial for informing coordinated efforts among stakeholders and policymakers to achieve meaningful and sustainable shifts towards plant-based diets, ultimately contributing to improved health and environmental outcomes. The framework underscores the need for context-specific interventions tailored to different consumer groups and the importance of continuous refinement and integration of new evidence to advance this critical area of research and practice. The authors emphasize that research on shifting from meat-based to increasingly plant-based diets should not necessarily disregard other theoretical frameworks in favor of the COM-B model. The COM-B offers a highly flexible and parsimonious overarching framework that can be used as a tool to encompass relevant constructs that are proposed by other theories, with a focused view on how to foster behavior change. The work concludes that the specific motivation, capability and opportunity factors such as those identified in this review should be tackled to successfully shape and sustain these transitions.