Impact of the Fukushima nuclear accident on obesity of children in Japan, using data from 2008 to 2014.

This study uses prefecture-level panel data from Japan for the period 2008?2014 to investigate the influence of the 2011 Fukushima nuclear accident on the z-score of body mass index (BMI z-score) and obesity rates of children over time. A difference-in-differences approach was used to show that: (1) For cohorts aged between 5 and 7 years old in 2010, BMI z-score and obesity rates in disaster-damaged areas were higher than those in other areas, although this was not observed for other cohorts; (2) For cohorts aged between 5 and 7 years old in 2010, the influence of the accident persisted even after 3 years; and (3) The differences in BMI z-score and obesity rate before and after the accident were larger for Fukushima Prefecture than other damaged areas (Iwate and Miyagi prefectures). We infer that health-conscious parents, whose children had lower BMIs, may have moved from Fukushima, increasing the BMI z-score of the population of children living in Fukushima by around 0.05 for the cohort aged 5?7. The enforced reduction in physical activity increased the BMI z-score of children living in Fukushima by around 0.19 for the cohort.