Abstract
Due to the significant impact of Western diets on the environment, interventions are being trialled in supermarkets, restaurants, and other settings to encourage sustainable food consumption (SFC). The Behaviour Change Technique Taxonomy (BCTTv1) lists and categorises Behaviour Change Techniques (BCTs), which facilitates the development and understanding of behaviour change interventions. However, its applicability to pro-environmental behaviour change has not been extensively explored. This systematic review uses the BCTTv1 to identify the BCTs that have been previously used to encourage SFC behaviours. Studies were retrieved from Scopus, PSYCInfo, GreenFILE, and the Web of Science Core Collection. Twenty-six interventions across 19 articles were reviewed, enabling the identification of 13 BCTs which were coded using the BCTTv1 and categorised according to their target behaviour and effect size. The most frequently applied BCTs were 12.1 ‘restructuring the physical environment’, which was used in the most effective interventions; 6.2 ‘social comparison’, which was used in interventions with smaller and more unpredictable effects; 5.3 ‘information about social and environmental consequences’; 5.2 ‘salience of consequences’; and 7.1 ‘prompts/cues’. Despite challenges in assessing the BCTs’ effectiveness due to multicomponent interventions and varying effects across different contexts, this review offers recommendations on changing SFC behaviour as well as the applicability of the BCTTv1 for SFC interventions.
Generated Summary
This systematic review investigates behavior change techniques (BCTs) used in interventions aimed at encouraging sustainable food consumption (SFC). The research focuses on identifying which BCTs have been previously employed and which appear most effective in promoting SFC behaviors. The study draws from Scopus, PSYCInfo, GreenFILE, and the Web of Science Core Collection, analyzing 26 interventions across 19 articles. The primary method involved coding intervention components using the Behaviour Change Technique Taxonomy (BCTTv1), a hierarchical classification of methods to change behavior. The review explores the use of BCTs to address the environmental impact of Western diets by promoting sustainable food choices in various settings. This study provides an overview of BCTs and their efficacy for future intervention development, aiming to advance the application of BCTTv1 in the context of pro-environmental behavior.
Key Findings & Statistics
- The review identified 13 different BCTs used across 26 interventions, tested in 22 field studies.
- Most studies were conducted in the United Kingdom (32%), the USA (27%), or Sweden (18%).
- Eight of the 26 interventions (31%) aimed to reduce meat consumption.
- Ten interventions (38%) targeted the consumption of vegetarian/vegan food.
- The most frequently used BCTs were 5.3 ‘Information about social and environmental consequences’ (12 instances), 5.2 ‘Salience of consequences’ (9 instances), 7.1 ‘Prompts/cues’ (9 instances), and 12.1 ‘Restructuring the physical environment’ (10 instances).
- Interventions aimed at reducing meat consumption most often used BCTs 5.3 ‘Information about social and environmental consequences’ (5 instances), 12.1 ‘Restructuring the physical environment’ (3), 12.5 ‘Adding objects to the environment’ (3), 5.2 ‘Salience of consequences’ (2), and 7.1 ‘Prompts/cues’ (2).
- Interventions to encourage veg*n food choices most commonly used BCT 12.1 ‘Restructuring the physical environment’ (4 instances), 6.2 ‘Social comparison’ (4), 5.2 ‘Salience of consequences’ (2), and 13.2 ‘Framing/reframing’ (2).
- Interventions to encourage consumption of lower-carbon foods frequently used BCTs 5.3 ‘Information about social and environmental consequences’ (6 instances) 5.2 ‘Salience of consequences’ (5), 7.1 ‘Prompts/cues’ (4), and 12.1 ‘Restructuring the physical environment’ (3), and 12.5 ‘Adding objects to the environment’ (1).
- The most effective interventions to encourage veg*n food choice used BCT 12.1 ‘Restructuring the physical environment,’ leading to a significant increase in veg*n orders.
- The study found that interventions using BCT 6.2 ‘Social comparison’ tended to have very small or null effects, and even backfired in two cases.
- All interventions aimed at promoting lower-carbon food choice had a significant effect on behavior, ranging from very small to moderate.
- The BCT 12.1 ‘Restructuring the physical environment’ had a statistically significant positive effect, ranging from very small to very large.
- The interventions that most effectively reduced meat consumption tended to use either BCT 5.3 ‘Information about social and environmental consequences’ or 12.1 ‘Restructuring the physical environment.’
- Interventions exclusively using BCT 6.2 ‘Social comparison’ tended to have very small or null effects, and even backfired in two cases.
Other Important Findings
- The review revealed that the BCT 12.1 ‘Restructuring the physical environment’ has particular potential for encouraging SFC.
- BCT 12.5 ‘Adding objects to the environment’ appeared in combination with various other BCTs in interventions which all had a significant effect on behavior.
- Interventions exclusively using BCT 6.2 ‘Social comparison’ tended to have very small or null effects, and even backfired in two cases.
- Interventions aimed at promoting lower-carbon food choice frequently used BCTs 5.3 ‘Information about social and environmental consequences’, 5.2 ‘Salience of consequences’, 7.1 ‘Prompts/cues’, and 12.1 ‘Restructuring the physical environment’.
- The use of multiple BCTs made it difficult to infer which BCTs were most effective.
- Interventions that effectively reduced meat consumption often used BCT 5.3 ‘Information about social and environmental consequences’ or 12.1 ‘Restructuring the physical environment’.
- BCT 7.1 ‘Prompts/cues’ appeared in two ineffective interventions.
Limitations Noted in the Document
- The lack of uniformity in reported effect size metrics and the use of multiple BCTs made it difficult to compare the effectiveness of different BCTs.
- The size classifications of effect sizes in this review might not be entirely appropriate, as they were not derived from behavioral science literature.
- The review relies on the reporting quality of previous interventions, which has been notably poor in the past.
- The BCTTv1 may be limited in accurately categorizing interventions in the domain of pro-environmental behavior change compared to newer and more complex tools.
- The review is limited by the fact that most of the studies were conducted in WEIRD countries.
Conclusion
This systematic review offers a structured overview of BCTs used in SFC interventions and provides some indication of which BCTs show promise for effectively changing SFC behavior. The study’s findings suggest the potential of BCT 12.1 ‘Restructuring the physical environment’ for encouraging SFC, while interventions using BCT 6.2 ‘Social comparison’ showed mixed results, with some even backfiring. The review underscores the importance of considering the full spectrum of influences on SFC before designing interventions, highlighting the need to go beyond awareness and knowledge raising to make sustainable dietary changes easier. The strategic application of effective BCTs can play a vital role in encouraging the broader adoption of sustainable diets, contributing to reducing the environmental impact of diets. The findings also indicate that the BCTTv1 is a useful framework for categorizing interventions, but the BCTO might offer a more fine-grained tool. Researchers should consider applying both tools to understand, compare, or develop interventions for SFC. This review highlights the need for more detailed and accurate reporting of intervention components, which would benefit both science and practice, paving the way for more effective interventions in the future. Moreover, the study emphasizes the need for future research testing behaviour change interventions in a wider variety of cultural contexts.