This study addresses the persistent intention–behaviour gap in sustainable food consumption by re-specifying intention not as a proximate behavioural driver but as an upstream commitment whose enactment is contingent on execution-stage control.
Drawing on the Theory of Planned Behaviour integrated with habit psychology, the study models sustainable food consumption as a habit-conditioned execution process. Survey data from 463 Vietnamese consumers were analysed using PLS-SEM with formative higher-order constructs, mediation, moderation and conditional indirect effects.
Attitude, subjective norms and perceived behavioural control strongly predict purchase intention, yet intention exhibits only a weak direct effect on consumption behaviour. Habit strength emerges as the dominant execution-stage mechanism, significantly mediating and suppressing intention enactment. Consumer innovativeness weakens habitual dominance and amplifies the indirect effect of intention on behaviour, revealing systematic heterogeneity in executional permeability.
The study advances sustainable consumption theory by resolving the intention–behaviour gap as an execution-stage control problem rather than a motivational deficit. It reconceptualises habit as a mediating mechanism, introduces consumer innovativeness as a boundary condition on routine dominance and demonstrates configurational rather than additive behavioural causality.
