Why don't they stay changed?

The multifactorial nature of cardiovascular disease means that preventive efforts often stress a variety of complex behavioural capabilities (eg, increasing physical activity, changing eating habits, quitting smoking, practising stress reduction techniques). A variety of theoretical models have been suggested to help explain and predict health behaviours; however, social cognitive theory provides one of the most comprehensive frameworks for understanding human behaviour. Important constructs of social cognitive theory that relate to the initiation and maintenance of behaviour change are reviewed here, including perceived threat, behavioural capability, expectancies, interdependence and environmental influence. Suggestions about how these constructs may be applied in health practice are provided.