Benefit framing, personality traits and intention to adopt a flexitarian diet

Shifting diets towards more plant-based patterns is important for public health and environmental sustainability, yet evidence on the effectiveness of behavioural interventions remains mixed. This study examines whether benefit framing influences willingness to adopt a flexitarian diet and whether responses vary by personality and socio-demographic characteristics.

In a between-subjects online experiment, 412 UK adults were randomly assigned to financial, health, environmental, or control conditions; 303 participants were included in the final analytical sample. Probit models with interaction terms and average marginal effects were estimated.

Health framing increased the probability of expressing a positive adoption intention by approximately 17 percentage points relative to the control condition, whereas financial and environmental framing had no statistically significant overall effects. Environmental morale and willingness to take risks were also positively associated with adoption intention. In the control condition, a one-standard-deviation increase in openness, and conscientiousness was associated with 12.8 and 9.1 percentage-point higher probabilities of a positive intention, respectively. Conditional treatment-effect analyses suggest a ceiling effect: among participants one standard deviation below the mean, health framing increased intentions by 36.5 percentage points for openness and 32.9 percentage points for conscientiousness, while environmental framing increased intentions by 25.5 percentage points for openness; these effects were not statistically significant at higher trait levels.

These findings indicate that the effectiveness of benefit-based messages may depend not only on message content but also on individual characteristics and suggest that more differentiated communication strategies may improve the relevance of sustainable-diet interventions.