This study examined chronological changes in attitudes towards foodstuffs from the areas contaminated by the Fukushima Daiichi nuclear disaster, using citizens’ data (n=1,752) from the panel surveys conducted in 4 waves between September 2011 and March 2014. Using the dual process theory of decision-making, the study attempts an empirical examination that includes the interaction of two factors: (1) anxiety regarding the radiation risks of the nuclear accident, which is hypothesized to lead to negative emotional decision-making following the formation of relevant attitudes, and (2) knowledge, higher-order literacy, and critical thinking, which are hypothesized to promote logical decision-making. Until three years after the nuclear accident, there was no large chronological variation in either anxiety regarding the radiation risks of the nuclear accident or attitudes toward foodstuffs from affected areas. The tendency regarding the latter was particularly strong in areas far from the location of the disaster. Negative attitudes regarding foodstuffs from affected areas were reduced through the possession of appropriate knowledge regarding the effects of radiation on the human body. However, the belief of possessing such knowledge may, conversely, hinder careful consideration with appropriate understanding.