Methods for identifying effective behavior change techniques for given behaviours and contexts all have important limitations. We need a way to combine methods to arrive at reliable effectiveness estimates.

HighlightsEvidence on transitions to more plant-based diets is increasing but still fragmented.This limits concerted efforts to successfully shape and sustain these transitions.We present a systematic review of relevant variables, framed as barriers and enablers.These were mapped into a coherent overarching framework of behavior change.Studies that integrate capability, opportunity and motivation variables are needed.3 Abstract BackgroundThere 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 approachEleven 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 conclusionsThis 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.

Use of natural language to represent behaviour change theories has resulted in lack of clarity and consistency hindering comparison, integration, development and use. This paper describes development of a formal system for representing behaviour change theories which aims to improve clarity and consistency. A given theory is represented in terms of 1) its component constructs (e.g., 'self-efficacy', 'perceived threat', 'subjective norm') which are labelled and defined, and 2) relationships between pairs of constructs, which may be causal, structural, or semantic. This formalism appears adequate to represent five commonly used theories (Health Belief Model, Information-Motivation-Behavioural Skill Model, Social Cognitive Theory, Theory of Planned Behaviour, and the Transtheoretical Model). Theory authors and experts judged that the system was able to capture the main propositions of the theories. Following this proof-of-concept, the next step is to assess how far the system can be applied to other theories of behaviour change.

The use of IOC significantly improves clinical, behavioral, and psychological determinants of periodontal health 4 months after treatment.