Lifestyle at 3 years of age and quality of life (QOL) in first-year junior high school students in Japan: Results of the Toyama Birth Cohort Study

Objective: The aim of this study was to determine whether some effects of childhood lifestyles at 3 years of age are associated with quality of life (QOL) in first-year junior high school students (JHSS). Method: Lifestyles including sleep, physical activity and dietary habits of 9,674 3-year-old children were obtained by questionnaire between 1992 and 1994. Assessments were undertaken with the Dartmouth Primary Care Co-operative Project charts in 9,574 first-year JHSS in 2002. Logistic regression analyses were used to explore the relationship between lifestyle in early childhood and QOL in first-year JHSS for the follow-up subjects. Results: After adjusting for demographic and familial factors at baseline, the results showed that later bedtime [odds ratio (OR) = 1.17, P = 0.043], later waking time (OR = 1.19, P = 0.039), short sleep duration (OR = 1.15, P = 0.061), physical inactivity (OR = 1.48, P = 0.022), skipping breakfast (OR = 1.56, P = 0.003), irregular snacks (OR = 1.43, P < 0.001), and frequent instant noodle consumption (OR = 1.49, P = 0.007) in early childhood increased the risk of poor QOL in first-year JHSS. The relationships were reinforced by a significant linear trend for almost all factors considered at baseline to QOL in first-year JHSS. Conclusion: Early childhood lifestyle factors, especially dietary habits, at 3 years of age have significant effects on QOL in first-year JHSS. This suggests that interventions as early as 3 years of age should be considered.