A survey of junior high school students' sleep habit and lifestyle in Okinawa.

A survey was made of the sleep and lifestyle activity patterns of 3754 students from 14 different junior high schools on Okinawa Island. The survey showed that bedtimes became progressively and significantly later as students ascended to higher grades, resulting in adolescent sleep debt. The later adolescents retired to sleep, there appeared significantly greater numbers suffering from insufficient sleep, who found difficulty in waking up, who arose later in the mornings, and who failed to eat breakfast. The study indicated that along with later bedtimes, staying up late resulted in deterioration of sleep health, poor dietary habits and feeling ill, contributing to sleepiness during class.