Tracking overweight and obesity in Japanese children; a six years longitudinal study

Childhood overweight/obesity is growing steeply, globally. It is usually regarded as a risk factor for severe obesity over life-time course. Here, we investigated temporal course of overweight/obesity development in Japanese school children. A six-year longi- tudinal study was performed on 16,245 Japanese primary school children (8,427 boys and 7,818 girls) comprising three cohorts of 1 st 3 rd grade. A baseline survey was conducted at 2001, followed by annual baseline studies from 20022007 to determine the prevalence and track overweight/obesity. Our results showed that the prevalence of overweight was 1523% in boys and 1518% in girls, however, for obesity it ranged between 47% n boys ; and 24% in girls. As regards for tracking status, 6080% of overweight and 3570% f obese Japanese primary school boys track into overweight or obese junior high school adolescents. However, these percentages are lower among primary school girls, where only 5070% overweight and 3060% obese primary school girls track into overweight and obese adolescents, respectively. We conclude that Japanese boys are fatter than girls ; and 80% of overweight/obese Japanese primary school children track into junior high school overweight/obese adolescents. J. Med. Invest. 57 : 114-123, February, 2010