Childhood obesity and physical fitness are increasing and decreasing among children in developed countries, respectively; this has become an international social problem. Recently, this tendency has appeared in the Asian region, particularly among urban-dwelling children in locations experiencing rapid economic development. After the Second World War, Japan experienced the earliest economic development in Asia; this led to intergenerational changes in body size and physical fitness among Japanese children. Japanese children’s current physical status may thus predict that of children in other Asian countries.
We reviewed Japanese children’s physical fitness and anthropometric data using nationally repre sentative surveys and comparing generations (e.g., grandparents vs. parents vs. children) to exam ine secular trends. As expected, currently, children are taller and heavier than parent-aged individu als were at the same age and the prevalence of obesity increased compared with 30 years ago.
Nonetheless, during the past decade, body weight and obesity have decreased. Current children are less physically fit than their parents’ generation was at the same age. Additionally, school nurses and PE teachers are increasingly reporting lifestyle-related diseases, injuries of the head and face, frac tures, and decreasing muscle strength among school children.
Finally, we present a small-scale study of lifestyle and behavior patterns among hunter-gatherer children living in African tropical forests and discuss ways to prevent child obesity and improve chil dren’s physical fitness and health.