EditorialGreat East Japan Earthquake: Proactive sharing of lessons learned After the Great East Japan Earthquake and subsequent Fukushima Daiichi nuclear power plant accident (Great East Japan Disaster, GEJD), numerous pediatric health challenges arose in the communities within the disaster-stricken area, and childhood obesity was one of them. Moriyama et al. identified an increased prevalence of obesity in elementary school students in Rikuzentakata City, Iwate Prefecture, Japan, 4 years after the earthquake and devastation by tsunami.1 They attributed the increase in obesity to sedentary life in temporary housing. This is closely connected to the current discussion of the nationwide study of obesity, given that the number of playground yards are decreasing due to conversion of the school yards to temporary housing.