Abstract
The purpose of this study is to find a better morning-evening type for keeping the good health practices. We investigated 345 students (74 males and 271 females) with self-administered questionnaire on health and behavior, including the seven health practices of Breslow (never smoking cigarettes, regular physical activity, moderate or no use of alcohol, 7-8 hr sleep/day regularly, maintaining proper weight, eating breakfast and no eating between meals), and the type of Morningness-Eveningness (M-E) introduced by Horne and Ostberg. The results were as follows: 1. Morning type students had more of seven health practices than intermediate type students followed by evening type students. 2. More evening type students than intermediate and morning type students complained tiredness and unhealthiness caused by the irregularity of their daily life. 3. About four of 5 students reported that their present living behavior had been acquired after the graduation of high school for each M-E type. Living behavior might be formed compartively in a short time after their high school age. Further inverstigation on the relationship between living behavior and individual difference in the circadian variation is still needed, but it is suggested that it is better for health to keep the morning type or to switch from the evening type or the intermediate type to the morning type in which healthy practices are maintained with ease.
