No abstract

An integrated-questionnaire was administered to a total of 4142 (2137 women, 2005 men; answer rate: 94.4%) university students and medical training schools students aged 18-40 y. The survey was carried out between May and October, 2004-2013. This questionnaire consisted of assessment of diurnal type, questions on sleep habits, mental health (upset emotionally, irritated, angered by small triggers, and suppressed), frequency of watching TV at night, use of mobile phone and playing TV games between 21:00 and 03:00 h, and questions on lighting conditions during the daytime and night. Sleep length in evening-type students (E-type; Diurnal Type Scores = 7-12) was shorter than in intermediate-types (I-type; DTS = 13-16) and morning-types (M-type; DTS = 17-28) on weekdays (p<0.001), whereas sleep length in evening-types was shorter than intermediate-and morning-type students at weekends (p<0.001). Mental health index scores of the E-type students were significantly lower than those of I-type and M-type students in both sexes (p<0.001). Seventy-three percent of E-type women students watched TV after 23:00 h, significantly higher than 65.0% and 52.5% of I-type and M-type females, respectively (p<0.001), and 70.4% of E-type male students watched the TV after 23:00 h, significantly higher than 66.1% and 59.7% of I-type and M-type males, respectively (p=0.001). With regard to lighting conditions in the room in the afternoon, a slightly lower, but significantly so, percentage of the E-type students used the sunlight coming through the window than did the other types (p<0.001). The frequency of having three nutritionally rich meals (especially breakfast) -including carbohydrates, proteins, vitamins and minerals -was significantly higher in M-type than I-types and E-types (p<0.001). Premenstrual symptoms (PMS) were significantly more severe in E-type than I-type and M-type females (p=0.002). Lighting conditions throughout the 24 hours and at breakfast can act as a strong zeitgeber for students and exert a great influence on their mental and physical health, and can also affect PMS in women students.

This study evaluates the effects of milk intake for 20 days at breakfast on diurnal type (chronotype), sleep habits and soccer performance in Japanese university male athletes attending a university soccer club. Seventy three athletes were asked to take 200 ml of cows' milk at breakfast for 21 consecutive days during November and December, 2014. Twenty athletes attending the same soccer club did not drink cows' milk for the same period of time and acted a control group. An integrated questionnaire was administered twice, before the intervention period and 1 month after it to all 93 participants. The questionnaire included questions on sleep habits and diurnal type. On the 10th day and 21st days of the intervention period, a questionnaire on performance/skill was administered to all participants. The group which drank cows' milk showed higher frequency of improvement of soccer performance than did the control group did (performance-where higher values indicate less skill: milk drinking group=29.92, control group=31.9 on day 10; milk drinking group=28.21, control group=31.9 on day 21), and also judged that their soccer performance had improved more after 21 days than 10 days of the intervention. Those participants who changed diurnal type to becoming more morning-typed were more likely to judge that their soccer performance had improved than did those who showed no change in diurnal type.

Tryptophan intake at breakfast has been known to be effective on promoting better mental health and morning-typed life through serotonin and melatonin synthesis. For Japanese children, milk seems to be important resource for taking tryptophan at breakfast because of limited meal time in the morning. This study tries to show the effects of milk intake at breakfast on circadian typology and mental health of Japanese infants aged 1 -6 years. An integrated questionnaire was administrated to 1100 infants aged 1 -6 years attending nursery schools or kindergarten in June 2012. Seven hundred and forty participants (67.3%, 360 females and 380 males, mean age: 3.5 ± 1.4) answered the questionnaire. The questionnaire included questions on sleep habits, the diurnal type scale by Torsvall and Åkerstedt (1980), questions on mental health (anger and depression), and meals contents and time. Infants who took milk at breakfast showed 21.2 (±3.4, n = 537) of the diurnal type scale scores on average which tended to be higher (more morning-typed) than 20.7 (±3.5, n = 142) (p = 0.085) shown by those who did not take milk. Infants who took carbohydrate (or carbohydrate and protein resource) plus milk at breakfast were significantly morning-typed than those who took only carbohydrate (or carbohydrate and protein resource) (p < 0.001). Infants who took milk at breakfast tended to be less frequently depressed than those who did not (p = 0.098). Taking milk at breakfast might be effective to promote serotonin synthesis in the morning which could improve mental health directly and become "inner" zeitgeber for circadian clocks in infants.

This study tries to investigate the current relationship between the habit to use mobile phone and the diurnal type scale and sleep habit in Japanese students.

This study examines relationship between drinking cows' milk at breakfast and several mental and physical characteristics (the diurnal type, sleep habits and mental condition as anger, out of control of emotion, irritation and depression) of Japanese small children aged 1-6 years old. A questionnaire study and an intervention one were performed in this study. An integrated questionnaire was administered, in July 2014 to 1112 participants attending one of 10 nursery school and 1 kindergarten located in Kochi (33˚N, 133˚E), Japan, and 582 parents (mostly mothers) which answered it instead of children (rate of answer: 51.9%). Intervention was done to 111 children attending the kindergarten. Seventy six parents answered the questionnaire which was administered 3 months after the intervention days of 21 (rate of answer: 51.9%). There are two contents of intervention, one is the distribution of cows' milk for 21 days to be drunk at breakfast and another is the distribution of leaflet entitled "Go to bed early! Get up early! and Take nutritionally rich breakfast and cows' milk!" just before the intervention. Just before the intervention, letter was distributed to 111 parents who were asked for their children to follow the contents of the leaflet and drink the cows' milk distributed every day for the 21 days. Small children who drink cows' milk at breakfast more than once per week and take nutritionally rich breakfast more than 4 times per week are more morning-typed than the other three groups in which children fit into one or none of the two issues of taking morning cows' milk

In this study, a teaching material as a picture leaflet for infant was made, and the educational effectiveness of the leaflet was examined on the infants who attend one of ten nursery schools or a Kindergarten affiliated to Faculty of Education, Kochi University. The title of the picture leaflet is "A picture book on diurnal rhythm! Let's take cow milk breakfast and become a morning-typed person!" (Seikatsu-rizumunoehon, gyunyudehayanehayaoki: in Japanese). An intervention study was performed using an integrated questionnaire. The questionnaire before the intervention was administered and parents of 820 infants (711 ones attending one of the 10 nursery schools and 109 ones attending the Kindergarten) answered the questionnaire instead. All parents were asked to read the picture leaflet to their children every day during three weeks intervention period of June, 2016. Ratio of infants who had the reading of the leaflet more than 1 time for the 3 weeks was 94.5% and the average days when the reading of it was performed was 10.8 days. More than half of parents (52.4%) performed the reading it more than 10 days. Eleven percent (18 parents) of parents performed the reading every day of 21 intervention-days. In the first week of intervention, about 60% (97 infants) of the parents performed the reading in more than 4 days. Infants who had the reading it from their parents everyday got up in earlier time significantly than those who did it not in every day (U-test, z = −4.33, p < 0.01). Infants who had the reading of it every day went to bed in earlier time than the other ones who did it not in every day (U-test, z = −7.731, p < 0.001), and they slept more hours than the other ones (U-test, z = −2.30, p < 0.001). In conclusion, the reading of a picture leaflet which recommends a morning-typed life seems to be effective for How to cite this paper: Kawamata, M., Kawasumi, R., Tsuji, F., Taniwaki, N., Kawada, T., Noji, T., Krejci, M., Nakade, M., Takeuchi 1622 Psychology infants to promote the morning-typed life and quality of life (QOL) even though the intervention period is short as three weeks.

Purpose: An intervention program called "Super Meal Education Program" was supported by Japanese Ministry of Arts, Sports, Sciences and Education. This program was implemented to improve meal habit and sleep habit and also to improve academic marks at school by Japanese compulsory schools students. The effects of the intervention were evaluated by comparing an integrated questionnaire study held both before and after the intervention of a half year. Method:The intervention program consists of a lecture on sleep health and diurnal rhythms of children by an university professor, a series of lectures and practical classes by elementary school teachers on foods which can be collected nearby, and also practical courses as excursions to learn traditional meals and several foods resources which are products nearby. Integrated questionnaire study and also government official academic achievement test were performed before and after the intervention 6 months in May and November, 2015. An integrated questionnaire was administrated to elementary school students of grades 1 to 6 (7-12 years old). For the younger students aged 6-9 years old, parents (mostly mothers) answered the questionnaire instead of their children. The integrated questionnaire included questions on the diurnal type scale (DTS), sleep habits, meal habits, and other questions on their environments and habits. Result:The rate of answer to the questionnaire was more than 95% and the number of data was 295 before and 286 after the intervention. In the histogram on distribution of the diurnal type scale scores (DTS) before intervention, 25 % of evening-typed students significantly shifted to significantly more morning-typed persons after that (p<0.001). There was significantly negative correlation between DTS scores before intervention and the amount of increased change in DTS during the intervention period (r=-390, r<0.001). For all students in the elementary school, there were no significant changes in sleep quality, bedtime in weekdays, wake up time and sleep hours before and after the intervention period. There was negative correlation between sleep hours in weekday before intervention and increased amount in sleep hours before and after that (r=-0.545, p<0.001).The longer the sleep hours become during intervention, the better the academic achievement mark was after the intervention (students in the second, third and fifth grades: r=0.369, p<0.01) in mathematics mark. Conclusion:At least for the students who had been originally evening-typed, the intervention on meal habits may be effective for longer sleep hours and improved school achievement marking.