This article considers changes in the perception and avoidance behavior of food risks over time. In Japan, consumers' concerns about the risks of radiation exposure via food consumption rose rapidly after the accident at the Fukushima Daiichi Nuclear Power Station in 2011. We conducted choice experiment surveys three months, seven months, and eleven months after the Fukushima accident and simulated the conditional means of willingness to pay (WTP) for avoiding radiation exposure via food consumption in each survey period. The results show that although the characteristics of changes in averting behaviors vary depending on the type of food, the heterogeneity in WTP values for avoiding food risk tends to reduce (broaden) when their magnitude decreases (increases).