This study proposes that snacking behaviour may be either reflective and deliberate or impulsive, thus following a dual-process account. We hypothesised that chronic individual differences in food related self-control would moderate the relationships between reflective and impulsive processes. The reflective route was represented by an attitude toward unhealthy snacking, while the impulsive route was represented by the tendency to buy snack on impulse. A web survey was conducted with 207 students and employees at a Norwegian university, and a moderated hierarchical regression analysis using structural equation modelling was used to estimate the theoretical model. The findings showed that both attitudes towards unhealthy snacking and impulsive snack buying tendency were positively related to snack consumption. Food related self-control moderated the relation between attitude and behaviour, as well as the relation between impulsive snack buying tendency and behaviour. The effect of attitude on consumption was relatively strong when food related self-control was strong, while the effect of impulsive snack buying on consumption was relatively strong when food related self-control was weak. The results thus suggest that while weak self-control exposes individuals vulnerable to impulsive tendencies, strong self-control does not necessarily lead to less unhealthy snacking, but this depends on the valence of an individual's attitude.