The association between device-measured sitting time and cardiometabolic health risk factors in children.

BACKGROUND: There is limited evidence of the associations between postural-derived sitting time, waist-worn derived sedentary time and children's health and the moderation effect of physical activity (PA). This study examined associations of children's device-measured sitting time with cardiometabolic health risk factors, including moderation by physical activity. METHODS: Cross-sectional baseline data from children (mean-age 8.2 ± 0.5 years) in Melbourne, Australia (2010) participating in the TransformUs program were used. Children simultaneously wore an activPAL to assess sitting time and an ActiGraph GT3X to assess sedentary time and physical activity intensity. Cardiometabolic health risk factors included: adiposity (body mass index [BMI], waist circumference [WC]), systolic and diastolic blood pressure (SBP, DBP), high-density lipoprotein (HDL), low-density lipoprotein (LDL), cholesterol, triglycerides, fasting plasma glucose (FPG), serum insulin, and 25-hydroxyvitaminD (25[OH]D). Linear regression models (n = 71-113) assessed associations between sitting time with each health risk factor, adjusted for different PA intensities (i.e. light [LIPA], moderate-vigorous intensities [MVPA], separately on each model), age, sex, adiposity, and clustering by school. Interaction terms examined moderation. The analyses were repeated using device-measured sedentary time (i.e. ActiGraph GT3X) for comparison. RESULTS: Sitting time was positively associated with SBP (b = 0.015; 95%CI: 0.004, 0.026), DBP (b = 0.012; 95%CI:0.004, 0.020), and FPG (b = 0.001; 95%CI: 0.000, 0.000), after adjusting for higher PA intensities. The association between sitting time and insulin (b = 0.003; 95%CI: 0.000, 0.006) was attenuated after adjusting for higher PA intensities. When the models were adjusted for LIPA and MVPA, there was a negative association with LDL (b=-0.001; 95%CI: -0.002, -0.000 and b=-0.001; 95%CI: -0.003, -0.000, respectively). There was a negative association of sedentary time with WCz (b=-0.003; 95%CI: -0.005, 0.000) and BMIz (b=-0.003; 95%CI: -0.006, -0.000) when the models were adjusted by MVPA. Sedentary time was positively associated with triglycerides (b = 0.001; 95%CI: 0.000, 0.001) but attenuated after adjusting for MVPA. No evidence of moderation effects was found. CONCLUSIONS: Higher volumes of sitting and sedentary time were associated with some adverse associations on some cardiometabolic health risk factors in children. These associations were more evident when sitting time was the predictor. This suggests that reducing time spent sitting may benefit some cardiometabolic health outcomes, but future experimental research is needed to confirm causal relationships and identify the biological mechanisms that might be involved. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12609000715279.

Cost-effectiveness of reducing children's sedentary time and increasing physical activity at school: the Transform-Us! intervention.

BACKGROUND: Improving physical activity and reducing sedentary behavior represent important areas for intervention in childhood in order to reduce the burden of chronic disease related to obesity and physical inactivity in later life. This paper aims to determine the cost-effectiveness of a multi-arm primary school-based intervention to increase physical activity and/or reduce sedentary time in 8-9 year old children (Transform-Us!). METHODS: Modelled cost-utility analysis, using costs and effects from a cluster randomized controlled trial of a 30-month intervention that used pedagogical and environmental strategies to reduce and break up sedentary behaviour (SB-I), promote physical activity (PA-I), or a combined approach (PA + SB-I), compared to current practice. A validated multiple-cohort lifetable model (ACE-Obesity Policy model) estimated the obesity and physical activity-related health outcomes (measured as change in body mass index and change in metabolic equivalent task minutes respectively) and healthcare cost-savings over the cohort's lifetime from the public-payer perspective, assuming the intervention was delivered to all 8-9 year old children attending Australian Government primary schools. Sensitivity analyses tested the impact on cost-effectiveness of varying key input parameters, including maintenance of intervention effect assumptions. RESULTS: Cost-effectiveness results demonstrated that, when compared to control schools, the PA-I and SB-I intervention arms were "dominant", meaning that they resulted in net health benefits and healthcare cost-savings if the intervention effects were maintained. When the costs and effects of these intervention arms were extrapolated to the Australian population, results suggested significant potential as obesity prevention measures (PA-I: 60,780 HALYs saved (95% UI 15,007-109,413), healthcare cost-savings AUD641M (95% UI AUD165M-$1.1B); SB-I: 61,126 HALYs saved (95% UI 11,770 - 111,249), healthcare cost-savings AUD654M (95% UI AUD126M-1.2B)). The PA-I and SB-I interventions remained cost-effective in sensitivity analysis, assuming the full decay of intervention effect after 10 years. CONCLUSIONS: The PA-I and SB-I Transform-Us! intervention arms represent good value for money and could lead to health benefits and healthcare cost-savings arising from the prevention of chronic disease in later life if intervention effects are sustained. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN83725066). Australia and New Zealand Clinical Trials Registry Number (ACTRN12609000715279).

Fathers' perceived role, self-efficacy and support needs in promoting positive nutrition and physical activity in the first 2000 days of life: a mixed methods study.

BACKGROUND: The first 2000 days of life are a crucial and opportunistic time to promote positive dietary and physical activity behaviours that can continue throughout life. The bulk of research on the impact of parents promoting positive dietary and physical activity behaviours has been on mothers, with the impact of fathers rarely investigated. The aim of this study is to investigate fathers' perceived role, self-efficacy and support needs in promoting positive dietary and physical activity behaviours in early childhood. METHODS: A sequential explanatory mixed methods study design consisted of a cross sectional survey of Australian fathers (n = 200) from a convenience sample, followed by semi-structured qualitative interviews (n = 21) with a purposeful sample of Australian fathers. RESULTS: Quantitative survey data revealed that more than 90.0% of fathers agreed that it is important to role model healthy eating and participating in physical activity with their babies, toddlers and children. A majority of fathers were confident in getting their child to eat fruit/ vegetables (90%) and playing with their child (80%). When searching for information about nutrition and physical activity, the highest proportion of fathers nominated online sources (52%) as their preferred source in survey data. Qualitative interview data revealed that while fathers exhibited high self-efficacy in their abilities, this was susceptible to deterioration due to feelings of isolation, pressures of fatherhood, a lack of information and resources that are father specific, and difficulties navigating the different types of information/resources to find what is right for them. CONCLUSIONS: Although possessing self-efficacy, being committed and seeking knowledge, many fathers found that useful information was hard to find and understand. Appropriate resources are therefore required to support the specific needs of fathers to promote positive dietary and physical activity behaviours in their infants and young children.

Priority populations' experiences of the accessibility and inclusion of recreation centres: a qualitative study.

BACKGROUND: Although the health benefits of physical activity are well documented, certain priority populations are often disproportionately insufficiently active and at higher risk of poor health. Recreation centres have the potential to provide accessible and supportive environments for physical activity for all. However, little is known about priority populations' experiences of these venues and their views of how accessibility and inclusion can be optimised. This study aimed to gain in-depth insights of recreation centre experiences and potential strategies for improving inclusion and accessibility amongst priority populations (women, older adults, ethnic minorities, persons living with disabilities/additional needs, individuals identifying as LGBTQIA+, low socio-economic position). METHODS: This qualitative study (2021-2022) involved 18 semi-structured individual interviews with adult priority population users of recreation centres (50% 65 + years, 61.2% female) in one Melbourne municipality. Participants were asked to discuss their positive and negative experiences at the centres and to identify strategies for enhancing accessibility and inclusion. Interviews were audio-recorded and transcribed verbatim. Content analysis was performed for data analysis. RESULTS: While many participants had positive views of the facilities and programs at the centres, as they met their needs, they also had suggestions for improving accessibility and inclusion. Similarly, most participants were happy with the communications, felt included, and perceived the culture positively. Those who did not feel included at the centres offered many potential strategies for changing the culture, modifying communications (e.g., signage), and establishing partnerships for better access and inclusion. CONCLUSIONS: The present study adds to essential knowledge concerning priority populations' experiences of recreation centres. For recreation facilities that were generally perceived as having positive inclusion and accessibility, the findings nonetheless highlighted suggestions for further enhancement. These strategies may be useful more broadly for improving accessibility and inclusion, thereby promoting physical activity and ultimately health for all.

Prevalence of toddlers meeting 24-hour movement guidelines and associations with parental perceptions and practices.

OBJECTIVES: Whether toddlers (1-2 years) meet 24-hour Movement Guidelines and how parental practices and perceptions are related to compliance are uncertain. This study: a) estimated the proportion of toddlers meeting individual and combined movement guidelines; and b) examined associations between parental perceptions/practices and toddlers' compliance with movement guidelines. DESIGN: Cross-sectional study. METHODS: Australian parents self-reported their parenting practices/perceptions (routines, co-participation, restrictions, concerns, knowledge) and toddlers' movement behaviours in the baseline assessment of Let's Grow (n=1145), a randomised controlled trial. The World Health Organization's Guidelines on Physical Activity, Sedentary Behaviour, and Sleep for children under 5 years were used to estimate the prevalence of compliance with individual and combined movement guidelines. Logistic models assessed cross-sectional associations. RESULTS: The prevalence of meeting guidelines was 30.9% for screen time, 82.3% for sleep, 81.6% for physical activity, 20.1% for combined, and 2.1% meeting none. Parents' knowledge of the guidelines, fewer concerns and more favourable restrictions concerning movement behaviours were associated with greater compliance with individual and combined movement guidelines. Routines for screen time and for combined behaviours were associated with adherence to their respective guidelines. Less co-participation in screen time and more co-participation in physical activity were associated with greater compliance with the relevant guidelines. CONCLUSIONS: Given only 20% of toddlers met all guidelines, strategies early in life to establish healthy movement behaviours, especially screen time, are needed. Future studies could target the parental practices/perceptions identified in this study to support toddlers with optimal sleep and physical activity and reduced screen time.

Are physical activity and sleep associated with emotional self-regulation in toddlers? a cross-sectional study.

BACKGROUND: Toddlerhood (2-3 years) is a crucial period for the development of physical activity, sleep, and emotional self-regulation skills. Although there is growing evidence of positive associations between physical activity, sleep, and emotional self-regulation in school-aged children, the associations in toddlers remain unclear. Thus, this study aimed to examine the association between physical activity, sleep, and emotional self-regulation in toddlers. METHODS: Baseline data from 1350 toddlers (2.2 ± 0.33 year) from the Let's Grow randomised controlled trial were used. Toddlers' total physical activity (TPA) and moderate- to vigorous-intensity physical activity (MVPA) were assessed via 4 + days of accelerometry and a 3-item parent-report scale. Parent-reported total sleep quantity was calculated using the sum of average night-time sleep and daytime nap durations. Sleep behaviour data including bedtime routine, bedtime resistance, sleep onset-delay, sleep duration, and night waking were collected using relevant subsections from the Child Sleep Habits Questionnaire (CSHQ) and Brief Infant Sleep Questionnaire revised (BISQ-R). A 4-item parent-report scale adapted from the Fast Track Project Child Behaviour Questionnaire was used to assess toddlers' emotional self-regulation. Linear regression models were used, adjusting for child age, sex, and parental education. RESULTS: Accelerometer-derived TPA, MVPA and parent-reported TPA were not associated with emotional self-regulation. Higher parent-reported MVPA (B = -0.01 CI95 -0.03, -0.003) was associated with poorer emotional self-regulation. Higher sleep duration was associated with better emotional self-regulation (B = 0.06 CI95 0.04, 0.08). The five sleep behaviours assessed were also positively associated with emotional self-regulation (all p < 0.01), with fewer problem sleep behaviours being associated with better emotional self-regulation. CONCLUSIONS: This cross-sectional study suggests that sleep may be important for emotional self-regulation in toddlers, but the role of physical activity remains unclear. These findings suggest that interventions targeting sleep duration and sleep behaviours during the early toddler years may benefit the positive development of emotional self-regulation skills in this population.

Association between physical activity and self-regulation in early childhood: A systematic review.

Physical activity and self-regulation are important predictors of pediatric overweight and obesity. Young children (0-5 years) with lower physical activity levels and poorer self-regulation skills are at greater risk for overweight. Despite growing evidence that the two constructs are interrelated, their association remains unclear in young children. This review systematically summarized associations between physical activity and self-regulation in early childhood and explored the directionality of associations. Searches were run in six electronic databases. Forty-seven papers met inclusion criteria. Only three studies investigated all three domains of self-regulation (behavioral, cognitive, and emotional). Overall, findings were inconclusive; studies reported weak to moderate positive associations (n = 17), inverse associations (n = 5), mixed associations (n = 15), null association (n = 2), and negative (n = 1) between physical activity and self-regulation. Compared with the emotional and cognitive domains, physical activity was most consistently positively associated with behavioral self-regulation. Only one study assessed bidirectional associations, reporting a positive association. The three studies that included global self-regulation showed contradicting findings. There is some evidence that physical activity dose and sex potentially confound these associations; however, further research is needed given the paucity of studies. This review highlights the need for more in-depth investigation of the complex association between physical activity and global self-regulation.

Examination of Physical Activity, Organized Sport, and Sitting Time Among Women and Mothers From Culturally and Linguistically Diverse Backgrounds.

BACKGROUND: Little evidence is available from culturally and linguistically diverse (CALD) communities on the association between motherhood and physical activity (PA). This study aimed to examine independent and joint associations of cultural background and motherhood with meeting PA guidelines, participation in organized sports, and high sitting time (>8 h/d). METHODS: We used self-reported cross-sectional data from survey 8 of the 1973-1978 cohort of the Australian Longitudinal Study on Women's Health. PA was measured using the Active Australia Survey while organized sport and sitting time were measured using single items. CALD was defined as being born in a non-English speaking country or primarily speaking a non-English language at home. Multivariable-adjusted logistic regression analyses were used to examine independent and joint associations. RESULTS: Data from 5967 women (mean age 42.4 [SD 1.5] y, 6.9% CALD, 81.2% mothers) were analyzed. Women of CALD background had lower odds of meeting PA guidelines (odds ratio; 95% confidence interval: 0.80; 0.64-0.98) and participation in organized sports (0.68; 0.54-0.86), but no statistically significant association with sitting time (0.90; 0.72-1.14). Mothers had lower odds of meeting PA guidelines (0.75; 0.64-0.87) and high sitting time (0.42; 0.36-0.49). Compared with non-CALD women without children, mothers (irrespective of cultural background) were less likely to meet PA guidelines and have high sitting time. The association of "cultural background and motherhood" with organized sports participation was only significant for CALD mothers. CONCLUSIONS: Increased efforts and investments are needed to ensure that sports and other PA promotion interventions are culturally sensitive and engaging for CALD women and those with children.

Fussy Eating Rescue, a mobile-web app for responsive feeding practises among parents of toddlers: protocol for a pilot randomised controlled feasibility trial.

BACKGROUND: Fussy eating is most often a developmentally typical behaviour, generally presenting during toddlerhood. However, up to half of parents of young children are concerned about fussy eating, and this concern may mediate the use of nonresponsive feeding practises, such as coercive or unstructured feeding and using food to reward eating. Despite the high prevalence of parental concern for fussy eating and the negative impacts nonresponsive feeding practises have on children's health and diets, no previous digital intervention to improve the feeding practises of parents of toddlers concerned about fussy eating has been evaluated. AIM: This article describes the protocol of a randomised controlled feasibility pilot aiming to evaluate Fussy Eating Rescue, a purely web app based intervention for parents of toddlers. The primary aim is to investigate feasibility and acceptability; secondary aims are to explore indications of intervention effect on parents' feeding practises or children's eating behaviours. METHODS: Fussy Eating Rescue features include: (1) a Tracker, that allows parents to track repeated offers of food, (2) Topics, providing information on fussy eating, effective feeding strategies, and general nutrition, (3) Rescues, containing quick references to material supporting Topics contents, (4) Recipes, and (5) SMS notifications. Parents of toddlers (12-36 months old, n = 50) who have concerns about fussy eating will be recruited via Facebook. Parents will be randomised to an intervention group, which receives access to the app for 6 weeks, or to wait-listed control. Outcomes will be assessed at baseline and 6 weeks after app use, using online questionnaires and app usage statistics. Primary outcomes include participant retention rate, intervention engagement, app usability, perceived ease in using the app, perceived usefulness of the app, and user satisfaction. Secondary outcome measures include parents' feeding practises and children's eating behaviours. DISCUSSION: Results will inform whether Fussy Eating Rescue is a feasible way to engage parents concerned for their toddler's fussy eating behaviours. If feasible and acceptable to users, a larger trial will further examine the efficacy of the Fussy Eating app in improving parents' feeding practises and children's eating behaviours. TRIAL REGISTRATION: Prospectively registered with the Australian New Zealand Clinical Trials Registry on 15 July, 2021 (ACTRN12621000925842).

Cross-sectional and prospective associations between behavioural patterns and adiposity in school-aged children.

OBJECTIVE: Behavioural patterns are important in understanding the synergistic effect of multiple health behaviours on childhood adiposity. Most previous evidence assessing associations between patterns and adiposity were cross-sectional and investigated two or three behaviour domains within patterns. This study aimed to identify behavioural patterns comprising four behaviour domains and investigate associations with adiposity risk in children. DESIGN: Parent-report and accelerometry data were used to capture daily dietary, physical activity, sedentary behaviour and sleep data. Variables were standardised and included in the latent profile analysis to derive behavioural patterns. Trained researchers measured children's height, weight and waist circumference using standardised protocols. Associations of patterns and adiposity measures were tested using multiple linear regression. SETTING: Melbourne, Australia. PARTICIPANTS: A total of 337 children followed up at 6-8 years (T2) and 9-11 years (T3). RESULTS: Three patterns derived at 6-8 years were broadly identified to be healthy, unhealthy and mixed patterns. Patterns at 9-11 years were dissimilar except for the unhealthy pattern. Individual behaviours characterising the patterns varied over time. No significant cross-sectional or prospective associations were observed with adiposity at both time points; however, children displaying the unhealthy pattern had higher adiposity measures than other patterns. CONCLUSION: Three non-identical patterns were identified at 6-8 and 9-11 years. The individual behaviours that characterised patterns (dominant behaviours) at both ages are possible drivers of the patterns obtained and could explain the lack of associations with adiposity. Identifying individual behaviour pattern drivers and strategic intervention are key to maintain and prevent the decline of healthy patterns.

Understanding the pathways between prenatal and postnatal factors and overweight outcomes in early childhood: a pooled analysis of seven cohorts.

BACKGROUND/OBJECTIVES: Childhood overweight and obesity are influenced by a range of prenatal and postnatal factors. Few studies have explored the integrative pathways linking these factors and childhood overweight. This study aimed to elucidate the integrative pathways through which maternal pre-pregnancy body mass index (BMI), infant birth weight, breastfeeding duration, and rapid weight gain (RWG) during infancy are associated with overweight outcomes in early childhood from ages 3 to 5 years. SUBJECTS/METHODS: Pooled data from seven Australian and New Zealand cohorts were used (n = 3572). Generalized structural equation modelling was used to examine direct and indirect associations of maternal pre-pregnancy BMI, infant birth weight, breastfeeding duration, and RWG during infancy with child overweight outcomes (BMI z-score and overweight status). RESULTS: Maternal pre-pregnancy BMI was directly associated with infant birth weight (ß 0.01, 95%CI 0.01, 0.02), breastfeeding duration ≥6 months (OR 0.92, 95%CI 0.90, 0.93), child BMI z-score (ß 0.03, 95%CI 0.03, 0.04) and overweight status (OR 1.07, 95%CI 1.06, 1.09) at ages 3-5 years. The association between maternal pre-pregnancy BMI and child overweight outcomes was partially mediated by infant birth weight, but not RWG. RWG in infancy exhibited the strongest direct association with child overweight outcomes (BMI z-score: ß 0.72, 95%CI 0.65, 0.79; overweight status: OR 4.49, 95%CI 3.61, 5.59). Infant birth weight was implicated in the indirect pathways of maternal pre-pregnancy BMI with RWG in infancy, breastfeeding duration, and child overweight outcomes. The associations between breastfeeding duration (≥6 months) and lower child overweight outcomes were fully mediated by RWG in infancy. CONCLUSIONS: Maternal pre-pregnancy BMI, infant birth weight, breastfeeding duration and RWG in infancy act in concert to influence early childhood overweight. Future overweight prevention interventions should target RWG in infancy, which showed the strongest association with childhood overweight; and maternal pre-pregnancy BMI, which was implicated in several pathways leading to childhood overweight.

Differing associations with childhood outcomes using behavioural patterns derived from three data reduction techniques.

BACKGROUND: Behavioural patterns help to understand the influence of multiple health behaviours on childhood outcomes. Behavioural patterns derived using different data reduction techniques can be non-identical and may differentially associate with childhood outcomes. This study aimed to compare associations of behavioural patterns derived from three methods with three childhood outcomes. METHODS: Data were from the Healthy Active Preschool and Primary Years study when children were 6-8 years old (n = 432). Cluster analysis (CA), latent profile analysis (LPA) and principal component analysis (PCA) were used to derive behavioural patterns from children's diet, physical activity, sedentary behaviour and sleep data. Behavioural data were obtained through parent report and accelerometry. Children's height, weight and waist circumference were measured by trained study staff. Health-related quality of life data were obtained using the Pediatric Quality of Life Inventory and academic performance scores were from a national test. Associations between derived patterns from each method and each of the outcomes were tested using linear regression (adjusted for child age and sex and parent education). RESULTS: Three patterns were each derived using CA and LPA, and four patterns were derived using PCA. Each method identified a healthy, an unhealthy and a mixed (comprising healthy and unhealthy behaviours together) pattern. Differences in associations were observed between pattern groups from CA and LPA and pattern scores from PCA with the three outcomes. CONCLUSIONS: Discrepancies in associations across pattern derivation methods suggests that the choice of method can influence subsequent associations with outcomes. This has implications for comparison across studies that have employed different methods.

Characteristics of tummy time and dose-response relationships with development in infants.

This study aimed to examine change in tummy time patterns and preferences in the first 6 months of life, as well as dose-response relationships between tummy time duration and development at 2, 4, and 6 months. Participants were parents of infants from the Early Movers project in Edmonton, Canada (baseline: n = 411). At 2, 4, and 6 months, infant tummy time duration and preference (i.e., 1 = really likes to 5 = really dislikes) and development (i.e., Ages & Stages Questionnaire (ASQ-3) communication, fine motor, gross motor, problem-solving, personal-social) were measured by a parental questionnaire. In a subsample (n = 127), tummy time patterns (i.e., bout frequency, mean and median bout length) were measured using a 3-day time-use diary. Tummy time bout frequency, bout length, and preference significantly increased over time. Linear dose-response relationships between tummy time duration and development outcomes were observed at 4 (gross motor) and 6 months (all development outcomes). Moreover, at 2 months, 30-44 min/day of tummy time was associated with a higher total development score (vs. < 15 min/day; B = 11.14; 95%CI: 1.60, 20.68). At 6 months, 61-120 min/day (vs. < 30 min/day; B = 27.12; 95%CI: 11.93, 42.32) and > 120 min/day (vs. < 30 min/day; B = 33.80; 95%CI: 18.90, 48.70) of tummy time were associated with higher total development scores. Differences in threshold doses between some developmental outcomes were observed. Conclusion: In the first 6 months of life, increases were observed in tummy time preference as well as tummy time bout frequent and length. This finding may explain why the optimal amount of tummy time needed for more advanced development appeared to increase with age. What is Known: • Tummy time is a type of physical activity in infancy. International and national guidelines recommend at least 30 minutes of tummy time per day for infants who are not yet mobile. What is New: • In the first six months of life, preference for tummy time as well as tummy time bout frequency and length increased. • Tummy time duration had dose-response associations with several development outcomes, and the optimal amount of tummy time needed for more advanced development appeared to increase with age.

Results from the Australian 2022 Report Card on physical activity for children and young people.

Background: Past Physical Activity Report Cards have indicated a minority of Australian children and young people are sufficiently active. The purpose of this paper is to summarise grades across 10 indicators of the 2022 Australian Physical Activity Report Card, to assess physical activity behaviours and supports. Methods: A development team consisting of research experts synthesised and evaluated national and state level data to inform grades for each indicator. Data were drawn from nationally and state/territory representative datasets spanning 2016-2021. Results: Overall Physical Activity Levels and Screen Time were both assigned grades of D-, remaining the worst performing indicators. Australia's best performing indicator was Community and the Built Environment (A-), followed by Organised Sport and Physical Activity (B-). Remaining indicators were Family and Peers (C+), School (C+), Strategies and Investments (C-), Active Transport (D-) and Physical Fitness (D-). Active Play was unable to be graded, due to lack of consensus on a primary metric for this indicator and a lack of representative data. Conclusion: Evidence suggests that physical activity levels of Australian children remain consistently low, despite access to and availability of facilities and open spaces. There is a strong need for a National Physical Activity Plan to address this. The theme for the 2022 Australian Physical Activity Report Card, REBOOT! Reimagining physically active lives encourages us all to think more imaginatively about how we might engage all children and young people through diverse physical activity opportunities to be more active.

The effectiveness of interventions during the first 1,000 days to improve energy balance-related behaviors or prevent overweight/obesity in children from socio-economically disadvantaged families of high-income countries: a systematic review.

This narrative systematic review examined effectiveness of interventions during pregnancy and up to 2 years of age in improving energy balance-related behaviors or prevent overweight/obesity in children from families experiencing socio-economic disadvantage. We identified 24 interventions, from 33 articles, since 1990. Overall, despite their heterogeneity and variability in internal and external validity, there was some evidence of beneficial impact of interventions on obesity risk (4/15), and associated behaviors, e.g.: breastfeeding (9/18), responsive feeding (11/16), diet (7/8), sedentary (1/3) and movement (4/7) behaviors, and sleep (1/2). The most effective interventions aimed at promoting breastfeeding commenced antenatally; this was similar for the prevention of obesity, provided the intervention continued for at least 2 years postnatally and was multi-behavioral. Effective interventions were more likely to target first-time mothers and involve professional delivery agents, multidisciplinary teams and peer groups. Among ethnic/racial minorities, interventions delivered by lay agents had some impact on dietary behavior but not weight outcomes. Co-creation with stakeholders, including parents, and adherence to theoretical frameworks were additional ingredients for more pragmatic, inclusive, non-judgmental, and effective programs. The growing body of evidence on obesity prevention interventions targeting families experiencing socio-economic disadvantage is promising for reducing early inequalities in obesity risk.

Transform-Us! cluster RCT: 18-month and 30-month effects on children's physical activity, sedentary time and cardiometabolic risk markers.

OBJECTIVE: To test the efficacy of the Transform-Us! school- and home-based intervention on children's physical activity (PA), sedentary behaviour (SB) and cardiometabolic risk factor profiles. METHODS: A 30-month 2×2 factorial design cluster randomised controlled trial delivered in 20 primary schools (148 Year 3 classes) in Melbourne, Australia (2010-2012), that used pedagogical and environmental strategies to reduce and break up SB, promote PA or a combined approach, compared with usual practice. Primary outcomes (accelerometry data; n=348) were assessed at baseline, 18 and 30 months. Secondary outcomes included body mass index (BMI) and waist circumference (WC) (n=564), blood pressure (BP) (n=537) and biomarkers (minimum n=206). Generalised linear mixed models estimated the interactive effects of the PA and SB interventions on the outcomes. If there was no interaction, the main effects were assessed. RESULTS: At 18 months, there were intervention effects on children's weekday SB (-27 min, 95% CI: -47.3 to -5.3) for the PA intervention, and on children's average day PA (5.5 min, 95% CI: 0.1 to 10.8) for the SB intervention. At 30 months, there was an intervention effect for children's average day SB (-33.3 min, 95% CI: -50.6 and -16.0) for the SB intervention. Children's BMI (PA and SB groups) and systolic BP (combined group) were lower, and diastolic BP (PA group) was higher. There were positive effects on WC at both time points (SB intervention) and mixed effects on blood parameters. CONCLUSIONS: The Transform-Us! PA and SB interventions show promise as a pragmatic approach for reducing children's SB and adiposity indicators; but achieving substantial increases in PA remains challenging. TRIAL REGISTRATION: ISRCTN83725066; ACTRN12609000715279.

Longitudinal associations between weight status and academic achievement in primary school children.

BACKGROUND: Evidence for longitudinal associations between childhood weight status and academic achievement remains unclear due to considerable heterogeneity in study design, measures of academic achievement and appropriate categorization of weight status. OBJECTIVE: To examine longitudinal associations between childhood weight status (underweight, healthy weight, overweight/obese) and academic achievement in the transition from preschool to primary (elementary) school among Australian school children. METHODS: Data were from the Healthy Active Preschool and Primary Years study. Height and weight, for calculating BMI were measured at baseline (preschool age 3-5 years; 2008/9) and follow-up (primary school age 6-8 years; 2011/12). Academic achievement was measured at age 9 years. RESULTS: No associations between BMI z-score or weight category in the preschool years and later NAPLAN scores were found for boys. For girls, having a higher BMI z-score (B = -13.68, 95%CI: -26.61, -0.76) and being affected by overweight (B = -33.57, 95%CI: -61.50, -5.24) in preschool was associated with lower language scores. Remaining affected by overweight from preschool to primary school was associated with lower numeracy (B = -25.03, 95%CI: -49.74, -0.33), spelling (B = -33.5, 95%CI: -63.43, -3.58), language (B = -37.89, 95%CI: -72.75, -3.03) and total achievement scores (B = -24.24, 95%CI: -44.85, -3.63) among girls. For boys, becoming affected by overweight was associated with lower spelling (B = -38.76, 95%CI: -73.59, -3.93) and total achievement scores (B = -27.70, 95%CI: -54.81, -0.58). CONCLUSIONS: Associations between being affected by overweight/obesity and poorer academic achievement were more pronounced in girls than boys, indicating potentially inequitable impacts of excess weight and highlighting the greater need for intervention among girls. However, stronger study designs are needed to confirm our findings.

Accelerometer-based osteogenic indices, moderate-to-vigorous and vigorous physical activity, and bone traits in adolescents.

OBJECTIVES: We investigated the associations of accelerometry-derived osteogenic indices (OIs), moderate-to-vigorous (MVPA), and vigorous intensity physical activity (VPA) with peripheral quantitative computed tomography (pCQT) parameters in 99 adolescents aged 10-13 years. METHODS: Bone parameters were assessed at the distal (4%) and shaft (66%) of the tibia using pQCT. Accelerometers were worn on the right hip for 7 consecutive days. OIs were calculated based on acceleration peak histograms either using all of the peaks (OI) or peaks with acceleration ≥5.2 g (HOI). MVPA and VPA were defined using previously published cut-points. RESULTS: HOI was positively associated with total area (Partial correlation= 0.22, 95% CI=0.01 to 0.41), cortical area (CoA) (0.33, 95% CI=0.13 to 0.50), and stress strain index (SSI) (0.29, 95% CI=0.09 to 0.47) of tibial shaft and with total density at the distal tibia (0.23, 95% CI=0.02 to 0.42). OI was positively associated with CoA (0.31, 95% CI=0.11 to 0.49) and SSI (0.26, 95% CI=0.05 to 0.44) of tibial shaft. MVPA was positively associated with CoA (0.28, 95% CI=0.07 to 0.46) of the tibial shaft. CONCLUSIONS: OI and HOI were positively associated with pQCT parameters while MVPA and VPA demonstrated less consistent associations with them.

Outdoor time, screen time and sleep reported across early childhood: concurrent trajectories and maternal predictors.

BACKGROUND: Understanding the developmental trajectories of outdoor time, screen time and sleep is necessary to inform early interventions that promote healthy behaviours. This study aimed to describe concurrent trajectories of outdoor time, screen time and sleep across the early childhood period and their maternal predictors. METHODS: Data across five time points at child age 4, 9, 19, 42 and 60 months from the INFANT intervention were analysed. Mothers reported their child's usual outdoor time, screen time and sleep duration, in addition to a range of maternal beliefs, attitudes, expectations and behaviours. Group-based multi-trajectory modelling was used to model concurrent trajectories of children's behaviours. Multinomial logistic regression models determined the associations of maternal predictors with trajectory groups, adjusting for child sex and baseline age, intervention allocation, and clustering by recruitment. RESULTS: Of the 542 children recruited, 528 had data for outdoor time, screen time and sleep at one or more time points and were included in trajectory analyses Four trajectories were identified: 'unstable sleep, increasing outdoor time, low screen' (~ 22% of sample), 'high outdoor time, low screen, high sleep' (~ 24%), 'high sleep, increasing outdoor time, low screen' (~ 45%), 'high screen, increasing outdoor time, high sleep' (~ 10%). The 'high sleep, increasing outdoor time, low screen' group, comprising the largest percentage of the sample, demonstrated the healthiest behaviours. Predictors of group membership included: views of physically active children, screen time knowledge, screen time use, self-efficacy, physical activity optimism, future expectations for children's physical activity and screen time, perceptions of floor play safety, and maternal physical activity, screen time, and sleep quality. CONCLUSIONS: Four distinct trajectories of outdoor time, screen time and sleep were identified, with the most common (and healthiest) characterized by high levels of sleep. Maternal beliefs, attitudes, expectations and behaviours are important in the development of movement behaviour trajectories across early childhood. Future interventions and public policy may benefit from targeting these factors to support healthy movement behaviours from a young age.

Adherence to Canadian 24-Hour Movement Guidelines among infants and associations with development: a longitudinal study.

BACKGROUND: To examine: 1) longitudinal adherence to the Canadian 24-Hour Movement Guidelines in a sample of infants and 2) associations between adherence to the guidelines over time and development. METHODS: Participants were 250 parent-infant dyads from the Early Movers project in Edmonton, Alberta. At 2, 4, and 6 months of age, physical activity, sedentary behaviour, sleep, and development were measured with a parental questionnaire that included items from the Ages & Stages Questionnaire (ASQ-3). Parents also reported the dates six major gross motor milestones were acquired during the first 18 months of life according to World Health Organization criteria. In a sub-sample (n = 93), movement behaviours were also measured with a time-use diary at 2, 4, and 6 months and gross motor development was measured by a physiotherapist using the Alberta Infant Motor Scale (AIMS) at 6 months. Guideline adherence was defined as: 1) ≥ 30 min/day of tummy time, 2) no screen time, some reading time, no restrained bouts > 1 h (time-use diary only), and 3) 14-17 h (2 months) or 12-16 h (4 and 6 months) of sleep per 24-h period. Generalized estimating equations were conducted as well as linear mixed models and linear regression models that adjusted for demographic characteristics. RESULTS: Few infants met the guidelines at all time-points (questionnaire: 2%; time-use diary: 0%). Infants that met a recommendation at 2 months, compared to those that did not, were 1.8-8.2 times more likely to meet that recommendation at subsequent time-points. Meeting more recommendations across time-points, according to both measures, was associated with a higher mean ASQ-3 gross motor score. Each additional time-point of tummy time recommendation adherence (questionnaire-measured) was associated with a 5-11-day earlier acquisition of independent sitting, crawling, and independent standing milestones. In the sub-sample, each additional time-point of guideline adherence was associated with a 16% higher AIMS score at 6 months. CONCLUSIONS: Guideline adherence was low across the first 6 months of infancy. Overall, meeting more recommendations over this period appeared important for gross motor development. Parents and caregivers should be targeted as early as possible with guideline dissemination and activation strategies to promote healthy infant development.