- 著者
- Miyo Nakade Hitomi Takeuchi Nozomi Taniwaki Teruki Noji Tetsuo Harada
- 出版者
- 日本生理人類学会
- 雑誌
- Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)
- 巻号頁・発行日
- vol.28, no.5, pp.239-245, 2009-09-30 (Released:2009-10-10)
- 参考文献数
- 32
- 被引用文献数
- 16 34
Tryptophan (Trp) intake at breakfast promotes morning-typed circadian typology and higher sleep quality in Japanese children aged 0–6 yrs (Harada et al., 2007). This effect may be accelerated by morning exposure to sunlight, which has not yet been tested. This study aimed to investigate such an effect in Japanese children. In May, 2006, an integrated questionnaire was administered to 0–6-year-old children attending one of 12 kindergartens. 906 parents answered the questionnaire for their children and themselves (response rate: 67.4%). The integrated questionnaire included the revised version for children of the Morningness-Eveningness (M-E) Questionnaire and questions on sleep, nutritional balance, mental health, and sunlight exposure. Analysis was made on data from 744 children aged 2–6 (385 girls, 359 boys) whose average M-E score was 20.6±3.46. Children who had breakfast at regular times tended to be more morning-typed and were less frequently angry (p=0.001) and depressed (p=0.007). Children who had nutritionally well-balanced breakfasts tended to be more morning-typed (p<0.001), and woke up and fell asleep at earlier times (p<0.001). Children with higher protein intake tended to have higher M-E scores (p<0.001) and earlier bedtime and wake-up time (p=0.003). Children exposed to sunlight for 30–60 min on their way to kindergarten showed more distinctive shifting-effects to morning-type with protein intake than those exposed to sunlight for less than 20 min (p=0.006). A well-balanced breakfast might be a strong zeitgeber for circadian oscillators of children, and the morning-type driving effect of protein intake could be accelerated by morning exposure to sunlight.