A systematic evaluation of physical activity and diet policies in Scotland: results from the 2021 Active Healthy Kids Report Card.

BACKGROUND: Policymaking regarding physical activity (PA) and diet plays an important role in childhood health promotion. This study provides a detailed examination of Scottish government and policy for child and adolescent PA and diet and discusses strengths and areas for improvement. METHODS: Scottish policy documents (n = 18 [PA]; n = 10 [diet])-published in 2011-20-were reviewed for grading using an adapted version of the Health-Enhancing Physical Activity Policy Audit Tool Version 2. RESULTS: There is clear evidence of leadership and commitment to improving PA and diet and tackling obesity in children and adolescents. The allocation of funds and resources for policy implementation has increased substantially over the past decade. Progress through early key stages of public policymaking-policy agenda and formation-has improved. However, there is limited information on later key stages, including policy monitoring and evaluation. CONCLUSIONS: Childhood PA and diet are a clear priority in Scotland, and PA and diet policies clearly support the desire to achieve other goals, including reducing inequalities and increasing active travel in Scotland. Nonetheless, future policies should be further strengthened through clear(er) plans of implementation, and monitoring and evaluation to support their societal impact.

Physical Activity Levels During School Recess in a Nationally Representative Sample of 10- to 11-Year-Olds.

PURPOSE: School recess provides a valuable opportunity for children's daily moderate- to vigorous-intensity physical activity (MVPA). This study aimed to quantify MVPA during school recess in a representative sample of Scottish children and examine whether recess MVPA varied by gender, socioeconomic status, season, urban/rural residency, and recess length. METHOD: Five-day accelerometry MVPA data were analyzed from 773 children (53.9% girls, 46.1% boys, 10- to 11-y-olds) from 471 schools. Binary logistic regression explored associations between meeting/not meeting the recommendation to spend 40% of recess time in MVPA and the aforementioned risk factors. Descriptive recess data were also analyzed. RESULTS: Participants spent an average of 3.2 minutes (SD 2.1) in MVPA during recess. Girls engaged in 2.5 minutes (SD 1.7) of MVPA compared with 4.0 minutes (SD 2.2) for boys. Only 6% of children met the recess MVPA recommendation. The odds of girls (odds ratio 0.09; 95% confidence interval, 0.04-0.25) meeting the recommendation was lower (P < .001) compared with boys. No statistically significant differences were observed in meeting the recommendation for the other risk factors. CONCLUSION: Levels of MVPA during school recess are very low in Scottish children, and interventions aimed at increasing MVPA during recess are needed.

Validation of mid-arm circumference for surveillance of obesity in African adolescent girls and adult women.

This study aimed to assess the validity of mid-arm circumference (MAC), also known as mid-upper arm circumference (MUAC), for classification of high body fatness in Namibian adolescent girls and women and to test whether classification accuracy of MUAC was higher than the traditional simple proxy for high fatness, the BMI. In 206 adolescent girls aged 13-19 years and 207 adult women aged 20-40 years, we defined obesity conventionally (BMI-for-age Z score ≥ 2·00, adolescents; adults BMI ≥ 30·0 kg/m2) and also defined obesity using published MAC cut-off values. 2H oxide dilution was used to measure total body water (TBW) to define high body fat percentage (≥ 30 % in the adolescents, ≥ 38 % in the adults), and we compared the ability of BMI and MAC to classify high body fatness correctly using sensitivity, specificity and predictive values. In the adolescents, obesity prevalence was 9·2 % (19/206) using BMI-for-age and 63·2 % (131/206) using TBW; sensitivity of BMI-for-age was 14·5 % (95 % CI 9·1, 22·0 %) but was improved significantly using MAC of 22·6 cm (sensitivity 96·9 %; 95 % CI 92·1 %, 99·3 %). In the adults, obesity prevalence was 30·4 % (63/207) using BMI and 57·0 % (118/207) using TBW, and sensitivity of BMI was 52·5 % (95 % CI 43·6, 62·2 %), but using a MAC of 30·6 cm sensitivity was 72·8 % (95 % CI 66·4, 82·6 %). Surveillance of obesity in African adolescent girls and adult women is likely to be improved substantially by use of MAC as an alternative to the BMI-for-age and BMI.

Cut-point values for classifying active children and validity and reliability of physical activity questionnaire for children in Morocco.

BACKGROUND: The Physical Activity Questionnaire for Children (PAQ-C) is widely used to assess physical activity in populations; however, there is a lack of information about the psychometric properties (validity and reliability) and about the PAQ-C score meaning in populations from low-middle income countries. AIMS: The aim of this study is to evaluate the reliability and validity of PAQ-C and to determine the cut-point values of PAQ-C using accelerometry as a reference in a group of Moroccan children. METHODS: In a sample of 171 children and adolescents aged 8 to 14 years, physical activity was assessed with the GT3X + accelerometer and the PAQ-C. PAQ-C was administered for a second time (retest) after 1 week for a subsample (n = 73). Reliability was analyzed by intraclass correlation coefficient (ICC). The PAQ-C was compared against count per minute CPM and moderate to vigorous intensity PA (MVPA) obtained by accelerometry. Receiver operating curve analyses were performed to assess the performance of PAQ-C in identifying MVPA as measured by accelerometry (reference method). RESULTS: Test-retest reliability was poor with an ICC = (0.48 [0.27; 0.63] for the whole sample, while for the ≥11 year group, the intra-class correlation coefficient was moderate (0.71 [0.42; 0.86]. PAQ-C scores were significantly related to accelerometry-derived metrics of physical activity, CPM (R = 0.29, P < 0.001) and MVPA (R = 0.26, P < 0.001). For the age group ≥11 years, the associations between PAQ-C Scores and CPM and MVPA were stronger, respectively, R = 0.37 (P < 0.001), R = 0.38 (P < 0.0001). We identified that a PAQ-C Score cut-point of 2.33 (95%CI [0.43-0.68]) discriminated adequately between those who met physical activity guidelines and those that did not in the overall sample. CONCLUSIONS: The PAQ-C is valid and useful to assess population level physical activity in those ≥11 years in Morocco and so might be helpful in population surveillance of physical activity in Moroccan adolescents.

Global Matrix of Para Report Cards on Physical Activity of Children and Adolescents With Disabilities.

This is an overview of the results from 14 countries or jurisdictions in a Global Matrix of Para Report Cards on physical activity (PA) of children and adolescents with disabilities. The methodology was based on the Active Healthy Kids Global Alliance's Global Matrix 4.0. Data were aligned with 10 indicators (Overall PA, Organized Sport, Active Play, Active Transport, Physical Fitness, Sedentary Behavior, Family & Peers, Schools, Community & Environment, and Government) to produce Para Report Cards. Subsequently, there were 139 grades; 45% were incomplete, particularly for Active Play, Physical Fitness, and Family & Peers. Collectively, Overall PA was graded the lowest (F), with Schools and Government the highest (C). Disability-specific surveillance and research gaps in PA were apparent in 14 countries or jurisdictions around the world. More coverage of PA data in Para Report Cards is needed to serve as an advocacy tool to promote PA among children and adolescents with disabilities.

Surveillance to improve physical activity of children and adolescents.

The global transition to current low levels of habitual physical activity among children and adolescents began in the second half of the last century. Low physical activity harms health in both the short term (during childhood and adolescence) and long term (during adulthood). In turn, low physical activity could limit progress towards several sustainable development goals, undermine noncommunicable disease prevention, delay physical and mental health recovery from the coronavirus disease 2019 pandemic, increase health-care costs and hinder responses to climate change. However, despite the importance of physical activity, public health surveillance among children and adolescents is very limited globally and low levels of physical activity in children is not on the public health agenda in many countries, irrespective of their level of economic development. This article details proposals for improvements in global public health surveillance of physical activity from birth to adolescence based on recent systematic reviews, international collaborations and World Health Organization guidelines and strategies. Empirical examples from several countries illustrate how improved surveillance of physical activity can lead to public health initiatives. Moreover, better surveillance raises awareness of the extent of physical inactivity, thereby making an invisible problem visible, and can lead to greater capacity in physical activity policy and practice. The time has arrived for a step change towards more systematic physical activity surveillance from infancy onwards that could help inform and inspire changes in public health policy and practice globally.

Durant la seconde moitié du siècle dernier, l'activité physique des enfants et adolescents a commencé à baisser à l'échelle mondiale pour atteindre le faible niveau actuel. La sédentarité a des effets néfastes sur la santé, tant à court terme (pendant l'enfance et l'adolescence) qu'à long terme (à l'âge adulte). Elle peut également entraver la progression vers de nombreux objectifs de développement durable, compromettre les efforts de prévention des maladies non transmissibles, retarder la guérison physique et mentale liée à la pandémie de maladie à coronavirus 2019, accroître les dépenses en soins de santé et freiner les réactions au changement climatique. Pourtant, malgré l'importance que revêt l'activité physique, rares sont les dispositifs de surveillance de la santé publique mis en place pour les enfants et adolescents dans le monde. En outre, la lutte contre la sédentarité chez les plus jeunes ne figure pas parmi les priorités de santé publique dans la plupart des pays, quel que soit le niveau de développement économique de ces derniers. Le présent article détaille une série de propositions visant à améliorer la surveillance de la santé publique en matière d'activité physique de la naissance à l'adolescence, fondées sur des revues systématiques récentes, des collaborations internationales ainsi que des stratégies et lignes directrices de l'Organisation mondiale de la Santé. Des exemples empiriques provenant de plusieurs pays illustrent comment cette amélioration peut déboucher sur des initiatives de santé publique. De plus, une meilleure surveillance permet de sensibiliser à l'ampleur de cette inactivité, donnant ainsi de la visibilité à un problème jusqu'alors invisible, et peut renforcer les capacités politiques et pratiques relatives à l'activité physique. Il est temps de procéder à un changement en profondeur afin de surveiller plus systématiquement l'activité physique dès le plus jeune âge, en vue d'orienter et d'encourager l'évolution des politiques et pratiques en la matière dans le monde.

La transición mundial hacia los niveles bajos actuales de actividad física regular entre niños y adolescentes comenzó en la segunda mitad del siglo pasado. La disminución de la actividad física perjudica la salud tanto a corto plazo (durante la infancia y la adolescencia) como a largo plazo (durante la edad adulta). A su vez, la falta de actividad física podría limitar el progreso hacia varios objetivos de desarrollo sostenible, socavar la prevención de enfermedades no transmisibles, retrasar la recuperación de la salud física y mental tras la pandemia de la enfermedad por coronavirus de 2019, aumentar los costes de la atención sanitaria y dificultar las respuestas al cambio climático. No obstante, a pesar de la importancia de la actividad física, la vigilancia de la salud pública entre los niños y los adolescentes es muy limitada a nivel mundial y los niveles bajos de actividad física en los niños no se incluyen en la agenda de salud pública de muchos países, sea cual sea su nivel de desarrollo económico. En este artículo, se detallan propuestas para mejorar la vigilancia de la actividad física en la salud pública a nivel mundial, desde el nacimiento hasta la adolescencia, a partir de recientes revisiones sistemáticas, colaboraciones internacionales y directrices y estrategias de la Organización Mundial de la Salud. Ejemplos empíricos de varios países ilustran cómo una mejor vigilancia de la actividad física puede conducir a iniciativas de salud pública. Asimismo, una mejor vigilancia aumenta la concienciación sobre el alcance de la inactividad física, haciendo evidente un problema poco visible, y puede conducir a una mayor capacidad en la política y la práctica de la actividad física. Ha llegado el momento de dar un paso adelante hacia una vigilancia más sistemática de la actividad física desde la infancia que podría ayudar a informar e inspirar cambios en la política y la práctica de la salud pública en todo el mundo.

Results from Scotland's 2021 report card on physical activity and health for children and youth: Grades, secular trends, and socio-economic inequalities.

Background: The 2021 Active Healthy Kids Scotland Report Card aimed to identify secular trends and socio-economic inequalities, and to assess the physical activity and health of children and youth prior to COVID-19. Methods: An expert panel searched for data published in 2018-2020. Grades were assigned to nationally representative data using the Active Healthy Kids Global Alliance methodology. Results: The expert panel, following national consultation, awarded the following grades: Community/Environment B-, Organized Sport and Physical Activity B-, Government/Policy C-/C+, Active Transportation C-, Family/Peers D-, Recreational Screen Time F. Five indicators were graded inconclusive (INC): Overall Physical Activity; Active Play; Physical Fitness; Diet; Obesity. Grades have remained stable or declined, and surveillance has reduced, increasing the number of INC grades. There were marked socio-economic inequalities for eight indicators (Recreational Screen Time; Overall Physical Activity; Organized Sport & Physical Activity; Active Transportation; Diet; Obesity; Family/Peers; Community/Environment). Conclusions: Despite a decade of favorable policy, physical activity and health of children and youth has not improved, and marked socio-economic inequalities continue to persist in Scotland. There is a clear need for greater monitoring of physical activity and health, and improved policy implementation and evaluation, particularly as many indicators and related inequalities may have worsened following the COVID-19 pandemic.

Results from the Japan 2022 report card on physical activity for children and youth.

Background/Objective: The 2020 Tokyo Olympics and Paralympic was held in 2021, although postponed due to the spread of COVID-19. This event might have an impact on physical activity (PA) of children and adolescents, but the national data on PA during the pandemic were not available. Therefore, the goal of the 2022 Japan Report Card on Physical Activity for Children and Youth (The 2022 Japan Report Card) is to assess and track levels of health behaviors related to PA, and health outcomes in Japanese children and adolescents, and environments and government strategy for PA just before the pandemic. Methods: The 2022 Japan Report Card consists of health behaviors and outcomes (8 indicators), and influences on health behaviors (4 indicators). Nationally representative data were used to score the indicators. Results: The key five health behaviors and outcomes (Overall PA: B-; Organized Sport: B-; Active Transportation: A-; Physical fitness: B, Weight status: A) were favorable. Sedentary Behavior and Sleep received C- and D- grades, respectively. Active Play could not be graded (INC). In the influences domain, Family and Peers was graded as C-, while School (B+), Community and Environment (B), and Government (B) were favorable. Conclusions: The 2022 Japan Report Card shows that Japanese children and adolescents had favorable levels of overall PA, active transportation to and from school, and weight status, and there was a generally favorable environment for PA and health, though sedentary behavior and sleep were unfavorable. Future nationally representative surveys on active play are needed.

Public health surveillance of habitual physical activity in adolescents and adults in Namibia: a cross-sectional validation of activity questionnaires against accelerometry.

BACKGROUND: Monitoring population-level physical activity is crucial for examining adherence to global guidelines and addressing obesity. This study validated self-reported moderate-to-vigorous physical activity (MVPA) against an accurate device-based method in Namibia. METHODS: Adolescent girls (n = 52, mean age 16.2 years [SD 1.6]) and adult women (n = 51, mean age 31.3 years [SD 4.7]) completed the PACE+/GPAQ self-report questionnaires and were asked to wear an Actigraph accelerometer for 7 days. Validity of self-reported MVPA was assessed using rank-order correlations between self-report and accelerometry, and classification ability of the questionnaires with Mann-Whitney tests, kappa's, sensitivity and specificity. RESULTS: In the adolescents, Spearman's rank coefficients between self-reported MVPA (days/week) and accelerometry measured MVPA were positive but not significant (r = 0.240; P = 0.104). In the adults, self-reported MVPA (minutes/day) was moderately and significantly correlated with accelerometer-measured MVPA (r = 0.396; P = 0.008). In both groups, there was fair agreement between accelerometry and questionnaire-defined tertiles of MVPA (adolescents κ = 0.267; P = 0.010; adults κ = 0.284; P = 0.008), and measured MVPA was significantly higher in the individuals self-reporting higher MVPA than those reporting lower MVPA. CONCLUSIONS: The PACE+ and GPAQ questionnaires have a degree of validity in adolescent girls and adult females in Namibia, though more suitable for population than individual level measurement.

Compliance with a physical activity guideline among junior high school students.

BACKGROUND: There were no nationwide moderate- to vigorous-intensity physical activity (MVPA) data relating to Japanese adolescents. This study assessed compliance with an MVPA guideline by adolescents, using a random sampling survey in Japan. The factors associated with compliance with the guideline were also examined. METHODS: Participants were first- to third-grade Japanese junior high school students (307 boys and 255 girls). We analyzed data from the National Sports-Life Survey of Teens 2019, which used the Japanese version of physical activity (PA) questions in the World Health Organization Health Behavior in School-aged Children survey and potential correlates of MVPA. RESULTS: Compliance with the PA guideline by the World Health Organization for Japanese students was 19.0% (95% confidence interval (CI), 15.8-22.3). The compliance of boys was significantly higher than that of girls (23.1%; 95% CI, 18.4-27.8; vs 14.1%; 95% CI, 9.8-18.4). The odds of meeting the PA guideline were significantly higher for boys in the second grade than boys in the first grade (odds ratio (OR) 1.78; 95% CI, 1.02-3.09), liking PA (for all: OR: 2.97; 95% CI, 1.32-6.69; for girls: OR: 2.99; 95% CI, 1.01-8.81), and sports participation (for all: OR: 4.77; 95% CI, 2.32-9.80; for boys: OR: 6.00; 95% CI, 1.81-19.89; for girls: OR: 4.08; 95% CI, 1.63-10.21). CONCLUSIONS: The results suggest that more than 80% of junior high school students were insufficiently physically active in Japan. Preferences for PA and sports participation may be important correlates of sufficient PA.

Associations between meeting 24-hour movement guidelines and health in the early years: A systematic review and meta-analysis.

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.

'Jump start' childcare-based intervention to promote physical activity in pre-schoolers: six-month findings from a cluster randomised trial.

BACKGROUND: Participation in adequate levels of physical activity during the early years is important for health and development. We report the 6-month effects of an 18-month multicomponent intervention on physical activity in early childhood education and care (ECEC) settings in low-income communities. METHODS: A cluster randomised controlled trial was conducted in 43 ECEC settings in disadvantaged areas of New South Wales, Australia. Three-year-old children were recruited and assessed in the first half of 2015 with follow-up 6 months later. The intervention was guided by Social Cognitive Theory and included five components. The primary outcome was minutes per hour in total physical activity during ECEC hours measured using Actigraph accelerometers. Intention-to-treat analysis of the primary outcome was conducted using a generalized linear mixed model. RESULTS: A total of 658 children were assessed at baseline. Of these, 558 (85%) had valid accelerometer data (mean age 3.38y, 52% boys) and 508 (77%) had valid accelerometry data at 6-month follow-up. Implementation of the intervention components ranged from 38 to 72%. There were no significant intervention effects on mins/hr. spent in physical activity (adjusted difference = - 0.17 mins/hr., 95% CI (- 1.30 to 0.97), p = 0.78). A priori sub-group analyses showed a greater effect among overweight/obese children in the control group compared with the intervention group for mins/hr. of physical activity (2.35mins/hr., [0.28 to 4.43], p = 0.036). CONCLUSIONS: After six-months the Jump Start intervention had no effect on physical activity levels during ECEC. This was largely due to low levels of implementation. Increasing fidelity may result in higher levels of physical activity when outcomes are assessed at 18-months. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12614000597695.

Variations in accelerometry measured physical activity and sedentary time across Europe - harmonized analyses of 47,497 children and adolescents.

BACKGROUND: Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe. METHODS: Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2-18 years) from 18 different European countries. RESULTS: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age. CONCLUSIONS: Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

Assessing the acceptability of an adapted preschool obesity prevention programme: ToyBox-Scotland.

BACKGROUND: Childhood obesity is a global public health issue. Interventions to prevent the onset of obesity in the early years are often implemented in preschool settings. The ToyBox intervention was delivered across Europe and targeted energy balance-related behaviours in preschools and children's homes through teacher-led activities and parental education materials and was adapted for use in Scotland. This study assessed the acceptability of the 18-week adapted intervention to both parents and teachers. METHODS: Mixed methods were employed to collect both qualitative and quantitative data. Preschool staff and children's parents/caregivers completed post-intervention feedback surveys, from which acceptability scores were calculated and presented as proportions. Focus groups were conducted with preschool staff, whereas parents/caregivers participated in semi-structured interviews. A thematic analysis was applied to qualitative data following the development of a coding framework. Quantitative and qualitative data were analysed using SPSS and NVivo 10, respectively. RESULTS: Preschool staff rated the intervention as highly acceptable based on post-intervention feedback surveys (80%; mean score 8.8/11). Lower acceptability scores were observed for parents/caregivers (49%; 3.9/8). Nine preschool practitioners participated in focus groups (n = 3). User-friendliness of the intervention materials, integration of the intervention with the curriculum, and flexibility of the intervention were identified as facilitators to delivery. Barriers to delivery were time, insufficient space, and conflicting policies within preschools with regard to changing classroom layouts. Parental interviews (n = 4) revealed a lack of time to be a major barrier, which prevented parents from participating in home-based activities. Parents perceived the materials to be simple to understand and visually appealing. CONCLUSIONS: This study identified a number of barriers and facilitators to the delivery and evaluation of the ToyBox Scotland preschool obesity prevention programme, which should be considered before any further scale-up of the intervention.

Non-linear longitudinal associations between moderate-to-vigorous physical activity and adiposity across the adiposity distribution during childhood and adolescence: Gateshead Millennium Study.

OBJECTIVE: Insufficient moderate-to-vigorous intensity physical activity (MVPA) is harmful for youth; however, the evidence for differential effects by weight status is limited. The study aimed to examine associations between MVPA and adiposity by weight status across childhood and adolescence. METHODS: Participants were from the Gateshead Millennium Study. Physical activity and body composition measures were taken at age 7 y (n = 502; measures taken between October 2006 and December 2007), 9 y (n = 506; October 2008-September 2009), 12 y (n = 420; October 2011-September 2012), and 15 y (n = 306; September 2014-September 2015). Participants wore an ActiGraph GT1M and epochs were classified as MVPA when accelerometer counts were ≥574 counts/15 s. Weight and height were measured using standardized methods and fat mass using bioelectrical impedance. Associations between MVPA and changes in BMI and FMI were examined by weight status using quantile regression. RESULTS: Higher MVPA was associated with lower FMI for the 25th, 50th, 75th, and 90th percentile and lower BMI at the 50th, 75th, and 90th percentile, independent of accelerometer wear time, sex, and sedentary time. The association between MVPA and change in adiposity was stronger in the higher than lower FMI and BMI percentiles (e.g., 1 h/day more MVPA was associated with a 1.5 kg/m2 and 2.7 kg/m2 lower FMI at the 50th and 90th FMI percentiles, respectively). CONCLUSIONS: The effect of MVPA on adiposity in the higher adiposity percentiles is stronger than reported to date. Given overweight and obese children are the highest risk group for later obesity, targeting MVPA might be a particularly effective obesity prevention strategy.

Correction to: Physical activity intensity, bout-duration, and cardiometabolic risk markers in children and adolescents.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Substituting prolonged sedentary time and cardiovascular risk in children and youth: a meta-analysis within the International Children's Accelerometry database (ICAD).

BACKGROUND: Evidence on the association between sitting for extended periods (i.e. prolonged sedentary time (PST)) and cardio-metabolic health is inconsistent in children. We aimed to estimate the differences in cardio-metabolic health associated with substituting PST with non-prolonged sedentary time (non-PST), light (LIPA) or moderate-to-vigorous physical activity (MVPA) in children. METHODS: Cross-sectional data from 14 studies (7 countries) in the International Children's Accelerometry Database (ICAD, 1998-2009) was included. Accelerometry in 19,502 participants aged 3-18 years, together with covariate and outcome data, was pooled and harmonized. Iso-temporal substitution in linear regression models provided beta coefficients (95%CI) for substitution of 1 h/day PST (sedentary time accumulated in bouts > 15 min) with non-PST, LIPA or MVPA, for each study, which were meta-analysed. RESULTS: Modelling substitution of 1 h/day of PST with non-PST suggested reductions in standardized BMI, but estimates were > 7-fold greater for substitution with MVPA (- 0.44 (- 0.62; - 0.26) SD units). Only reallocation by MVPA was beneficial for waist circumference (- 3.07 (- 4.47; - 1.68) cm), systolic blood pressure (- 1.53 (- 2.42; - 0.65) mmHg) and clustered cardio-metabolic risk (- 0.18 (- 0.3; - 0.1) SD units). For HDL-cholesterol and diastolic blood pressure, substitution with LIPA was beneficial; however, substitution with MVPA showed 5-fold stronger effect estimates (HDL-cholesterol: 0.05 (0.01; 0.10) mmol/l); diastolic blood pressure: - 0.81 (- 1.38; - 0.24) mmHg). CONCLUSIONS: Replacement of PST with MVPA may be the preferred scenario for behaviour change, given beneficial associations with a wide range of cardio-metabolic risk factors (including adiposity, HDL-cholesterol, blood pressure and clustered cardio-metabolic risk). Effect estimates are clinically relevant (e.g. an estimated reduction in waist circumference of ≈1.5 cm for 30 min/day replacement). Replacement with LIPA could be beneficial for some of these risk factors, however with substantially lower effect estimates.

Correction to: A closer look at the relationship among accelerometer-based physical activity metrics: ICAD pooled data.

Following publication of the original article [1], the author reported that the name of the collaborator group was missing from the author group.

A closer look at the relationship among accelerometer-based physical activity metrics: ICAD pooled data.

BACKGROUND: Accelerometers are widely used to assess child physical activity (PA) levels. Using the accelerometer data, several PA metrics can be estimated. Knowledge about the relationships between these different metrics can improve our understanding of children's PA behavioral patterns. It also has significant implications for comparing PA metrics across studies and fitting a statistical model to examine their health effects. The aim of this study was to examine the relationships among the metrics derived from accelerometers in children. METHODS: Accelerometer data from 24,316 children aged 5 to 18 years were extracted from the International Children's Accelerometer Database (ICAD) 2.0. Correlation coefficients between wear time, sedentary behavior (SB), light-intensity PA (LPA), moderate-intensity PA (MPA), vigorous-intensity PA (VPA), moderate- and vigorous-intensity PA (MVPA), and total activity counts (TAC) were calculated. RESULTS: TAC was approximately 22X103 counts higher (p < 0.01) with longer wear time (13 to 18 h/day) as compared to shorter wear time (8 to < 13 h/day), while MVPA was similar across the wear time categories. MVPA was very highly correlated with TAC (r = .91; 99% CI = .91 to .91). Wear time-adjusted correlation between SB and LPA was also very high (r = -.96; 99% CI = -.96, - 95). VPA was moderately correlated with MPA (r = .58; 99% CI = .57, .59). CONCLUSIONS: TAC is mostly explained by MVPA, while it could be more dependent on wear time, compared to MVPA. MVPA appears to be comparable across different wear durations and studies when wear time is ≥8 h/day. Due to the moderate to high correlation between some PA metrics, potential collinearity should be addressed when including multiple PA metrics together in statistical modeling.