Reasoned versus reactive prediction of behaviour: a meta-analysis of the prototype willingness model.
OBJECTIVE To investigate the prototype-willingness model (PWM) for eating behaviour in general and in the peer context in order to gain further evidence on the PWM and social-reactive processes in adolescents' eating behaviour. DESIGN A longitudinal study was conducted. PWM variables for unhealthy and healthy eating were assessed at baseline in 356 adolescents (mean age 12.61 years). MAIN OUTCOME MEASURES Eating behaviour was measured four weeks after baseline by two indicators: general eating pattern index (self-report) and consumption of unhealthy and healthy snacks in the peer context (behavioural observation). For both, structural equation models were conducted introducing PWM variables for either unhealthy or healthy eating. RESULTS The PWM was mainly confirmed for the eating pattern index; intention, willingness and prototype perception had direct effects. Differences between unhealthy and healthy eating were found. Moreover, the PWM contributed to the prediction of healthy, but not unhealthy, snack consumption over and above current hunger; willingness had a direct effect. CONCLUSIONS The PWM can be applied to predict and understand adolescents' eating behaviour. Social-reactive processes, namely willingness and prototype perception, are behavioural determinants that should be considered in theory and as novel targets in health promotion interventions.