The role of perceived need within the theory of planned behaviour: a comparison of exercise and healthy eating

Objectives. This study examined the effect of perceived need on exercise and healthy eating using the theory of planned behaviour (TPB). In addition, it investigated the determinants of perceived need.

Method. Participants completed a questionnaire measuring components of TPB and perceived need. A follow-up questionnaire I week later measured behaviour. The questionnaires were completed by e-mail. The initial questionnaire was completed by 331 adults, and 286 follow-up questionnaires were returned.

Results. Perceived behavioural control was the main predictor of exercise intention and affective attitude was the main predictor of healthy eating intention. Perceived need significantly contributed to the prediction of healthy eating intention but not to exercise intention. Intention and perceived behavioural control predicted actual behaviour but perceived need did not. Reasons reported for the perception of needing to engage in both behaviours mainly focused on physical health and weight control.

Conclusions. Reasons reported for low perceived need suggest that the concept of perceived need may be rather ambiguous, particularly in the case of exercise. Therefore, further research is needed to elucidate the role of perceived need in relation to a variety of health behaviours.