BACKGROUND: Changes in socioeconomic inequalities in health behaviours following the COVID-19 pandemic remain unknown, particularly among Japanese school-aged adolescents. Therefore, in this study, we examined changes in socioeconomic inequalities in school-aged adolescents' health behaviours, including physical activity (PA), screen time (ST), sleep duration, breakfast consumption, and bowel movement frequency, before and after the pandemic. METHODS: This three-wave repeated cross-sectional study utilised data from the 2019, 2021, and 2023 National Sports-Life Survey of Children and Young People in Japan, analysing data from 766, 725, and 604 participants aged 12-18 years, respectively. Favourable health behaviours were defined as moderate-to-vigorous PA of ≥60 min/day, ST <2 h/day, sleep duration of 8-10 h, daily breakfast consumption, and bowel movements at least every 3 days. Absolute and relative socioeconomic inequalities were quantified using the slope index of inequality (SII) and the relative index of inequality (RII). Temporal changes were analysed using quadratic trend analyses, employing interaction terms between socioeconomic status and survey year. RESULTS: Significant quadratic trends indicated that socioeconomic inequalities in breakfast consumption decreased substantially from 2019 (SII: 20.7%, RII: 5.09) to 2021 (SII: -0.1%, RII: 0.95) but resurged in 2023 (SII: 16.2%, RII: 3.70). This resurgence may have been primarily driven by changes among those in the moderately low-income (poverty level II) and higher-income groups, which had a breakfast consumption rate of 81.0, 87.0, and 76.4% in 2019, 2021, and 2023, and 88.7, 82.1, and 87.5%, respectively. Among low-income households, adherence to PA recommendations significantly declined from 18.6% to 5.3%, and ST adherence worsened over the study period. No significant inequalities or trends were observed for sleep duration or bowel movement frequency across survey years. CONCLUSIONS Socioeconomic disparities in breakfast consumption among Japanese school-aged adolescents resurfaced after initially narrowing during the pandemic, likely driven by changes in moderately low-income and higher-income groups. Among low-income households, adherence to PA and ST guidelines declined over time. However, at the population level, socioeconomic inequalities in PA did not exhibit a consistent trend of widening or narrowing. This study highlights the need for sustained public health initiatives to address these socioeconomic disparities.
Adolescent ; Child ; Female ; Humans ; Male ; Breakfast ; COVID-19/psychology* ; Cross-Sectional Studies ; Exercise ; Health Behavior ; Japan/epidemiology* ; Screen Time ; Sleep ; Socioeconomic Factors ; East Asian People

BACKGROUND: Smoking among Japanese adolescents has decreased noticeably. However, little is known whether the decreasing trend in adolescent smoking can be seen across all socioeconomic status (SES) groups. This study aimed to examine trends in socioeconomic inequalities in smoking among Japanese adolescents between 2008 and 2016. METHODS: We conducted a repeated cross-sectional study using data from three surveys of high school students in Okinawa, Japan, in 2008, 2012, and 2016. The study participants consisted of 7902 students in grades 10 through 12 (15-18 years). Smoking was assessed as current cigarette use. SES indicators included familial SES (parental education and family structure) and student's own SES (school type). To evaluate absolute and relative inequalities, prevalence differences (PDs) and ratios (PRs) between low and high SES groups were estimated. The slope index of inequality (SII) and relative index of inequality (RII) were also calculated. RESULTS: Smoking prevalence among boys and girls significantly declined from 11.5% and 6.2% in 2008 to 4.7% and 1.9% in 2016, respectively. Similar decreasing trends in smoking were found among most of the SES groups. The PDs and SII for parental education in boys and family structure in girls decreased over time while those for school type persisted among boys and girls. The PRs and RII for school type in boys increased while those for other SES indicators among both sexes remained stable over time. CONCLUSIONS Smoking among Japanese adolescents has been declining and time trends of socioeconomic inequalities in smoking varied by absolute and relative measures. Further policies and/or interventions to reduce smoking inequalities should focus on the context of schools, especially in vocational high schools.
Adolescent ; Cross-Sectional Studies ; Female ; Humans ; Japan ; Male ; Prevalence ; Socioeconomic Factors ; Tobacco Smoking/epidemiology*