This systematic review examined the compliance with the 24-h movement guidelines, and investigated its associations with health indicators for healthy children under 5 years of age. MEDLINE, PsycINFO, EMBASE, PubMed, Web of Science and SPORTDiscus were searched for peer-reviewed studies and the last search was conducted on 27 October 2020. The Newcastle–Ottawa Scales were used to assess the quality of included studies. Eighteen articles including 8,943 participants from 11 countries were included. On average around 13% of the children met all three guidelines. Meta-analyses of the associations between meeting all three guidelines and adiposity yielded no significant results (r = – 0.03; 95% CI = – 0.12, 0.06; I² = 51%; P = 0.48). Meeting more guidelines was associated with better psychosocial health (3/4 studies). Associations between meeting individual or combined guidelines and motor development yielded mixed results (2/2 studies), while no associations between meeting guidelines and cognitive development were observed (1 study). Compliance with all three guidelines was low. Further evidence is required to understand the associations between meeting the 24-h movement guidelines and health outcomes. Nevertheless, there was evidence of a dose-response relationship between meeting the guidelines and better psychosocial health in the early years.

This study aimed to investigate the extent to which preschool children in Hong Kong meet the World Health Organization’s (WHO) 24-h movement guidelines and to examine the associations between meeting the guidelines and body weight status. Data from 251 preschoolers (141 boys) aged between 3 and 6 years were analysed. The children wore an activPAL for 7 consecutive days to measure physical activity and sleep. Their screen time was reported by their parents using validated questions. Their body weight status was classified as underweight, normal weight or overweight/obese. A total of 2.9% of the preschoolers met all 3 movement guidelines. Children in compliance with the physical activity, screen time and sleep guidelines accounted for 14.5%, 67.4%, and 39.0% of the sample, respectively. There was no significant association between meeting the individual or combined guidelines and body mass index or the odds ratio for being of normal weight. Meeting more guidelines was not associated with body mass index or the odds ratio for being normal weight. Compliance with the 24-h movement guidelines was extremely low among preschool children in Hong Kong. Meeting the 24-h movement guidelines was not associated with a favourable weight status among preschoolers. Novelty: Compliance with the WHO 24-h movement guidelines was extremely low for the early years in Hong Kong. Further evidence is needed to understand the associations between meeting the guidelines and weight status among preschoolers.

Background: Short-form videos (SFVs) have emerged as a dominant trend in digital content sharing over the past decade, gaining rapid global popularity. An increasing number of studies have explored the association between SFV use and mental health, yet current empirical evidence remains inconsistent. Objective: This study aimed to provide a comprehensive synthesis examining the relationship between SFV usage and mental health outcomes, distinguishing between problematic and routine usage behaviors. Methods: Web of Science, PubMed, Scopus, Embase, PsycInfo, SportDiscus, and ProQuest were searched for relevant literature up to January 3 , 2026. Statistical metrics reflecting the relationship between SFV use and mental health outcome indicators were extracted for meta-analysis, such as Pearson correlation coefficients, Spearman’s rank correlation coefficients, and β coefficients. For intervention and longitudinal studies, we extracted the baseline correlation coefficients. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the risk of bias. Results: A total of 58 studies, with a cumulative sample of 96,676 participants, were included in the analysis. Results showed no significant correlations between SFV use and positive psychological states, but significant positive correlations with negative psychological states, including depression ( r =0.24, 95% CI 0.15-0.33), anxiety ( r =0.26, 95% CI 0.17-0.35), stress ( r =0.41, 95% CI 0.38-0.56), negative affect ( r =0.22, 95% CI 0.10.33), loneliness ( r =0.33, 95% CI 0.25-0.41), and boredom ( r =0.42, 95% CI 0.29-0.53). Subgroup analyses revealed substantial differences between usage patterns: problematic use demonstrated significant negative associations with subjective well-being ( r =−0.25, 95% CI −0.35 to −0.14) and positive correlations with adverse mental health outcomes, while routine usage showed no significant associations with negative affect and exhibited a negative but nonsignificant correlation with anxiety ( r =−0.02, 95% CI −0.18 to 0.14). Additionally, while some studies reported significant associations between routine SFV use (time spent or frequency) and mental health outcomes, these findings were less consistent and showed smaller effect sizes compared to the more robust correlations found with problematic use measures. This suggests that the relationship between time spent on SFV and mental health may be less stable than that of problematic use patterns, highlighting the importance of considering qualitative aspects of usage rather than merely quantitative metrics. Conclusions: This meta-analysis suggests that SFV use is associated with adverse mental health outcomes. Future research should use objective measurement instruments to capture contemporary SFV usage patterns and differentiate between distinct types of engagement. Additionally, studies with greater geographical diversity and longitudinal or experimental designs are needed to establish causality and examine temporal changes in these associations.

This study examined the longitudinal changes of movement behaviors and their relationships with posttraumatic stress disorder (PTSD) among university students during the coronavirus disease 2019 in China. A total of 569 university students completed online surveys twice (Time 1: between December 2020 and January 2021; Time 2: between November and December 2021). Physical activity, sedentary behavior, sleep duration and quality, as well as PTSD were self-reported. According to Canadian 24-h movement guidelines, the longitudinal shifts in each movement behavior from Time 1 to Time 2 were divided into four categories (consistently meeting the guidelines, from meeting to not meeting the guidelines, from not meeting to meeting the guidelines, and consistently not meeting the guidelines). Generalized linear mixed models were conducted using 410 valid responses (20.2 ± 1.0 years old at Time 2, 41.2% males). From Time 1 to Time 2, 22.2%, 2.0%, and 45.6% of the students consistently met the physical activity, sedentary behavior, and sleep guidelines, respectively. Compared to those who consistently met the sedentary behavior guideline, students who consistently failed to meet or changed from meeting to not meeting the guidelines had higher levels of PTSD. Students who had poor sleep quality at both time points or changed from good to bad sleep quality had higher levels of PTSD than those who maintained good sleep quality over time. Compared to those who consistently failed to meet the guideline, students who consistently met the PA guideline had higher levels of PTSD. These findings highlight the needs to improve and maintain healthy behaviors for mental health.