This study investigated the cultural differences of a dual-motivation model of unhealthy risk behaviour in the Netherlands and Japan. Our model assumes dual motivations involved in unhealthy eating behaviour, a behavioural willingness that leads behaviour unintentionally or subconsciously and a behavioural intention that leads planned or conscious behaviour. Participants consisted of 243 Dutch students and 321 Japanese students, who completed a questionnaire assessing the dual motivations, descriptive norms, injunctive norms, attitude, self-control and consumption of unhealthy snacks and sweet foods. As a result, Dutch students had a stronger behaviour control than Japanese students. The effect of behavioural intention on unhealthy eating was stronger in Dutch students than in Japanese students. Moreover, the behavioural willingness determined unhealthy eating only in Japanese students. Our study suggested that unhealthy eating behaviours tend to be intentional for individualistic cultures and unintentional for collectivistic cultures.