Hedayatrad, LeilaStewart, TomPaine, Sarah-JaneMarks, EmmaWalker, CarolineDuncan, Scott2026-05-202026-05-202022-10-04International Journal of Behavioral Nutrition and Physical Activity, ISSN: 1479-5868 (Print); 1479-5868 (Online), BMC, 19(1), 131-. doi: 10.1186/s12966-022-01358-11479-58681479-5868http://hdl.handle.net/10292/21155BACKGROUND: The time that children spend in physical activity, sedentary behaviour, and sleep each day (i.e., 24-h time-use behaviours), is related to physical and mental health outcomes. Currently, there is no comprehensive evidence on New Zealand school-aged children's 24-h time-use behaviours, adherence to the New Zealand 24-h Movement Guidelines, and how these vary among different sociodemographic groups. METHODS: This study utilises data from the 8-year wave of the Growing Up in New Zealand longitudinal study. Using two Axivity AX3 accelerometers, children's 24-h time-use behaviours were described from two perspectives: activity intensity and activity type. Compositional data analysis techniques were used to explore the differences in 24-h time-use compositions across various sociodemographic groups. RESULTS: Children spent on average, 31.1%, 22.3%, 6.8%, and 39.8% of their time in sedentary, light physical activity, moderate-to-vigorous physical activity, and sleep, respectively. However, the daily distribution of time in different activity types was 33.2% sitting, 10.8% standing, 7.3% walking, 0.4% running, and 48.2% lying. Both the activity intensity and activity type compositions varied across groups of child ethnicity, gender, and household income or deprivation. The proportion of children meeting each of the guidelines was 90% for physical activity, 62.5% for sleep, 16% for screen time, and 10.6% for the combined guidelines. Both gender and residence location (i.e., urban vs. rural) were associated with meeting the physical activity guideline, whereas child ethnicity, mother's education and residence location were associated with meeting the screen time guideline. Child ethnicity and mother's education were also significantly associated with the adherence to the combined 24-h Movement Guidelines. CONCLUSIONS: This study provided comprehensive evidence on how New Zealand children engage in 24-h time-use behaviours, adherence to the New Zealand 24-h Movement Guidelines, and how these behaviours differ across key sociodemographic groups. These findings should be considered in designing future interventions for promoting healthy time-use patterns in New Zealand children.Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.https://creativecommons.org/licenses/by/4.0/Compositional data analysisPhysical activityScreen timeSedentary behaviourSleepTime-use behaviours32 Biomedical and Clinical Sciences4206 Public Health42 Health Sciences3202 Clinical SciencesPreventionPediatric Research InitiativeSleep ResearchPhysical ActivityBehavioral and Social ScienceSocial Determinants of Health3 Good Health and Well Being11 Medical and Health Sciences13 EducationPublic Health3210 Nutrition and dietetics4202 Epidemiology4207 Sports science and exerciseChildExerciseHumansLongitudinal StudiesNew ZealandScreen TimeSedentary BehaviorSleepChildExerciseHumansLongitudinal StudiesNew ZealandScreen TimeSedentary BehaviorSleepHumansExerciseLongitudinal StudiesSleepChildNew ZealandScreen TimeSedentary BehaviorChildExerciseHumansLongitudinal StudiesNew ZealandScreen TimeSedentary BehaviorSleepJournal ArticleOpenAccess10.1186/s12966-022-01358-1