Predicting Malaysian household food waste behaviour through an integrated framework of theory of planned behaviour (TPB) and theory of interpersonal behaviour (TIB)

Food waste by households is increasing rapidly in developing countries like Malaysia, contributing to environmental damage, higher food costs and threaten reliable food supply. Existing research based on the Theory of planned behaviour (TPB) has largely emphasized rational decision making, overlooking the influence of emotions, facilitating conditions, and habits on household food waste behaviour. This study integrates the TPB with the Theory of interpersonal behaviour (TIB) and develops a research framework that incorporates constructs derived from both cognitive and affective dimensions, facilitating conditions, and habits-oriented constructs to predict both the intention to reduce food waste and actual food waste behaviour. Data were collected from 397 Malaysian households via a questionnaire survey, and analysed using PLS-SEM. Results show that food planning, health risk concern, attitude, negative emotions, and subjective norm significantly influence the intention to reduce food waste, with food planning showing the strongest positive effect, while health risk concern has a negative effect. Unexpectedly, perceived behavioural control did not influence intention. As for food waste behaviour, perceived behavioural control and intention were significant positive predictors, whereas being a good food provider has a significant negative effect. Food planning, healthy diet concern, and cost savings do not predict behaviour. These findings suggest policymakers refocus interventions on strengthening public awareness and emotional accountability, enhancing food planning infrastructure, and reshaping social norms around responsible consumption.