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We present development and validation of the Digital Addiction Scale for Teenagers (DAST), describing the pilot study (N = 40 students) and main study (N = 4493) with Estonian students aged 11–19, in spring 2020. Our aim was to create a scale suitable for psychoeducational assessment of teenagers’ behaviour and feelings towards digital devices. We used the mixed research framework (Onwuegbuzie, Bustamante, & Nelson, 2010). Half of the study sample was collected before the coronavirus crisis (Sample 1: 1972 students) and the rest of it during a distance learning period (Sample 2: 2521 students). We found that factor structure in both subsamples were similar. The DAST shows a negative relation with emotional school engagement and life satisfaction and positive correlations with school burnout, learning difficulties and screen time. We discuss potential uses of the scale for assessing health related digital competences.

Background: Since only few longitudinal studies with appropriate study designs investigated the relationship between objectively measured physical activity (PA) and overweight, the degree PA can prevent excess weight gain in children, remains unclear. Moreover, evidence is limited on how childhood overweight determines PA during childhood. Therefore, we analyzed longitudinal trajectories of objectively measured PA and their bi-directional association with weight trajectories of children at 2- and 6-year follow-ups. Methods: Longitudinal data of three subsequent measurements from the IDEFICS/I.Family cohort study were used to analyze the bi-directional association between moderate-to-vigorous PA (MVPA) and weight status by means of multilevel regression models. Analyses comprised 3393 (2-year follow-up) and 1899 (6-year follow-up) children aged 2–15.9 years from eight European countries with valid accelerometer data and body mass index (BMI) measurements. For categorized analyses, children’s weight status was categorized as normal weight or overweight (cutoff: 90th percentile of BMI) and children’s PA as (in-) sufficiently active (cutoffs: 30, 45 and 60 min of MVPA per day). Results: Children engaging in at least 60 min MVPA daily at baseline and follow-ups had a lower odds of becoming overweight (odds ratio [OR] at 2-year follow-up: 0.546, 95% CI: 0.378, 0.789 and 6-year follow-up: 0.393, 95% CI: 0.242, 0.638), compared to less active children. Similar associations were found for 45 min MVPA daily. On the other side, children who became overweight had the lowest odds to achieve 45 or 60 min MVPA daily (ORs: 0.459 to 0.634), compared to normal weight children. Conclusions: Bi-directional associations between MVPA and weight status were observed. In summary, at least 60 min MVPA are still recommended for the prevention of childhood overweight. To prevent excess weight gain, 45 min MVPA per day also showed preventive effects. CC BY 4.0© The Author(s). 2021 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.Correspondence: pohlabeln@leibniz-bips.de

This study was conducted under the umbrella of the ActiveBrains and the SmarterMove projects supported by the MINECO/FEDER (DEP2013-47540, DEP2016-79512-R, RYC-2011-09011) and the CoCA project supported by the European Union's 2020 research and innovation programme (667302). JHM is supported by a grant from the Spanish Ministry of Education, Culture and Sport (FPU15/02645). AR is supported by the NIHR Leicester Biomedical Research Centre, and the Collaboration for leadership in Applied Health Research and Care (CLAHRC) East Midlands. SS is supported by the French National Research Agency (ANR-19-CE36-0004-01). RW is supported by a Medical Research Council Industrial Strategy Studentship (MR/S502509/1). Additional funding was obtained from the Andalusian Operational Programme supported with European Regional Development Funds (ERDF in English, FEDER in Spanish, project ref: B-CTS-355-UGR18), the University of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of Excellence; Scientific Excellence Unit on Exercise and Health (UCEES), Junta de Andalucia,Consejeria de Conocimiento, Investigacion y Universidades and European Regional Development Funds (ref. SOMM17/6107/UGR). In addition, funding was provided by the SAMID III network, RETICS, funded by the PN I+D+I 2017-2021 (Spain), ISCIIISub-Directorate General for Research Assessment and Promotion, the European Regional Development Fund (ERDF) (Ref. RD16/0022), the EXERNET Research Network on Exercise and Health in Special Populations (DEP2005-00046/ACTI)., The inter-relationship between physical activity, sedentary behaviour and sleep (collectively defined as physical behaviours) is of interest to researchers from different fields. Each of these physical behaviours has been investigated in epidemiological studies, yet their codependency and interactions need to be further explored and accounted for in data analysis. Modern accelerometers capture continuous movement through the day, which presents the challenge of how to best use the richness of these data. In recent years, analytical approaches first applied in other scientific fields have been applied to physical behaviour epidemiology (eg, isotemporal substitution models, compositional data analysis, multivariate pattern analysis, functional data analysis and machine learning). A comprehensive description, discussion, and consensus on the strengths and limitations of these analytical approaches will help researchers decide which approach to use in different situations. In this context, a scientific workshop and meeting were held in Granada to discuss: (1) analytical approaches currently used in the scientific literature on physical behaviour, highlighting strengths and limitations, providing practical recommendations on their use and including a decision tree for assisting researchers’ decision-making; and (2) current gaps and future research directions around the analysis and use of accelerometer data. Advances in analytical approaches to accelerometer-determined physical behaviours in epidemiological studies are expected to influence the interpretation of current and future evidence, and ultimately impact on future physical behaviour guidelines., Spanish Government DEP2013-47540 DEP2016-79512-R RYC-2011-09011, CoCA project - European Union's 2020 research and innovation programme 667302, Spanish Government FPU15/02645, NIHR Leicester Biomedical Research Centre, Collaboration for leadership in Applied Health Research and Care (CLAHRC) East Midlands, French National Research Agency (ANR) ANR-19-CE36-0004-01, Medical Research Council Industrial Strategy Studentship MR/S502509/1, Andalusian Operational Programme, European Regional Development Funds (ERDF in English, FEDER in Spanish) B-CTS-355-UGR18, University of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of Excellence, Scientific Excellence Unit on Exercise and Health (UCEES), Junta de Andalucia,Consejeria de Conocimiento, Investigacion y Universidades, European Commission SOMM17/6107/UGR, SAMID III network, RETICS - PN I+D+I 2017-2021 (Spain), EXERNET Research Network on Exercise and Health in Special Populations DEP2005-00046/ACTI, ISCIIISub-Directorate General for Research Assessment and Promotion, European Commission RD16/0022

Descriptively, personality refers to relatively enduring, socially and/or personally important patterns of behaviour, thought, and psychological states that are characteristic to and individual. Personality descriptions (either from self-reports or behaviour observations) are causally heterogenous, reflecting, for example, self-presentational concerns in addition to the workings of functional elements of personality (called here the “personality system”). The functional elements can be subdivided into temperament, habits and knowledge, and self-regulation. These components form a nested hierarchy where each “upper” level controls those below it; the use of cultural ‘tools’ (symbolic representations of concepts and ideas) allows for more complex (but not necessarily more adaptive) ways of control. Behavioural observations and questionnaires are influenced by all three categories of the functional elements, but longitudinal design (either developmental or micro-longitudinal) can help pinpoint their relative contribution.

Background: Since only few longitudinal studies with appropriate study designs investigated the relationship between objectively measured physical activity (PA) and overweight, the degree PA can prevent excess weight gain in children, remains unclear. Moreover, evidence is limited on how childhood overweight determines PA during childhood. Therefore, we analyzed longitudinal trajectories of objectively measured PA and their bi-directional association with weight trajectories of children at 2- and 6-year follow-ups. Methods: Longitudinal data of three subsequent measurements from the IDEFICS/I.Family cohort study were used to analyze the bi-directional association between moderate-to-vigorous PA (MVPA) and weight status by means of multilevel regression models. Analyses comprised 3393 (2-year follow-up) and 1899 (6-year follow-up) children aged 2-15.9 years from eight European countries with valid accelerometer data and body mass index (BMI) measurements. For categorized analyses, children's weight status was categorized as normal weight or overweight (cutoff: 90th percentile of BMI) and children's PA as (in-) sufficiently active (cutoffs: 30, 45 and 60 min of MVPA per day). Results: Children engaging in at least 60 min MVPA daily at baseline and follow-ups had a lower odds of becoming overweight (odds ratio [OR] at 2-year follow-up: 0.546, 95% CI: 0.378, 0.789 and 6-year follow-up: 0.393, 95% CI: 0.242, 0.638), compared to less active children. Similar associations were found for 45 min MVPA daily. On the other side, children who became overweight had the lowest odds to achieve 45 or 60 min MVPA daily (ORs: 0.459 to 0.634), compared to normal weight children.

Background: Childhood obesity is increasing globally with widening socioeconomic inequalities. It is unclear if differences in the accumulation and intensity distribution of children’s physical activity is contributing to these rising disparities. We investigated if the intensity patterning of physical activity differs between socioeconomic groups across Europe and if this relationship differs by national level income inequality and age to help explain obesity disparities. Methods: We pooled and harmonised individual-participant accelerometer-assessed activity and socioeconomic position (SEP) data from 36 European child studies. Included participants were between 5 to 16 years of age with valid accelerometer data (≥480 minutes of daily wear time on 3 days), parental education and anthropometric measurements. Study-level multivariable linear regression models were run to assess differences in moderate-vigorous physical activity (MVPA), vigorous physical activity (VPA) and adiposity by socioeconomic position (by parental education). Effects were pooled in random effect meta-analyses. Findings: 26,915 participants (mean age: 10·1y [SD:1.2]; 51·7% female) from 16 European countries met the inclusion criteria. Meta-analyses revealed proportionally more average daily minutes of VPA were performed by children from a higher socioeconomic position (High vs low SEP, b: 0·57, 95%CI: 0·28, 0·85 mins), despite lower overall levels of physical activity (MVPA; b: -1·51, 95%CI: -2·36, -0·67 mins). Higher intensity activity in children from a higher socioeconomic position was paralleled by lower levels of adiposity measured by BMI z-score (b: -0·20, 95%CI: -0·24, -0·16). Stepwise differences were apparent moving from low to medium to high socioeconomic position [e.g. BMI z-score: (Low vs Med SEP; b: -0·10, 95%CI: -0·14, -0·07) (Low vs High SEP; b: -0·20, 95%CI: -0·24, -0·16)]. Inequalities in VPA and BMI z-score widened with age and were not affected by national level income inequality. Interpretation: Lower levels of adiposity in children from a higher socioeconomic position are paralleled by relatively higher amounts of VPA despite overall lower levels of MVPA. Physical activity promotion efforts should focus on providing opportunities for less affluent children to be vigorously active. Funding Statement: BHF, CRUK, ESCR, MRC, Wellcome Trust, Research Council of Norway Declaration of Interests: All authors declare that they have no conflicts of interest. Ethics Approval Statement: The authors declared not applicable.

This study reports the psychometric properties of the Estonian short version of the Hierarchical Personality Inventory for Children (HiPIC), a measure for assessing children's personality traits according to the five-factor model. Personality traits of 2009 Estonian kindergarten and elementary school children (982 boys and 1027 girls) ranging from 2 to 11 years were rated by their primary caregivers. 1087 children were assessed twice, with about a 2-year interval. At the second time, parents additionally completed the Estonian Brief Big Five Inventory (EBBFI). The domain scales of the Estonian HiPIC demonstrated acceptable internal consistency, with alphas ranging from 0.73 to 0.84. Test-retest correlations over two years were moderate to high, ranging from 0.57 to 0.69 for domain scales. Factor congruence between the Estonian and the original Flemish version increased as children grew older. Convergent correlations of HiPIC and EBFFI ranged from 0.63 to 0.79 demonstrating a high level of correspondence between the two measures. Analyses of longitudinal changes and cross-sectional differences in mean levels revealed an increase in Benevolence and decreases in Extraversion and Emotional Stability with age. Thus, the Estonian version provided further support for the validity and reliability of the HiPIC.

Habitually barefoot (HB) children from the Kalenjin tribe of Kenya are known for their high physical activity levels. To date, there has been no comprehensive assessment of foot structure and function in these highly active and HB children/adolescents and link with overuse injuries. PURPOSE: The aim of this research is to assess foot structure, foot function, injury and physical activity levels in Kenyan children and adolescents who are HB compared with those who were habitually shod (HS). METHODS: Foot structure, function, injury prevalence, and physical activity levels were studied using two studies with equal numbers of HS and HB. HS and HB children and adolescents were matched for age, sex, and body mass. Foot arch characteristics, foot strength, and lower-limb injury prevalence were investigated in Study 1 (n = 76). Heel bone stiffness, Achilles tendon moment arm length and physical activity levels in Study 2 (n=62). Foot muscle strength was measured using a strength device TKK 3360 and heel bone stiffness by bone ultrasonometry. The moment arm length of the Achilles tendon was estimated from photographs and physical activity was assessed using questionnaires and accelerometers. RESULTS: Foot shortening strength was greater in HB (4.8 ± 1.9 kg vs 3.5 ± 1.8 kg, P < 0.01). Navicular drop was greater in HB (0.53 ± 0.32 cm vs 0.39 ± 0.19 cm, P < 0.05). Calcaneus stiffness index was greater (right 113.5 ± 17.1 vs 100.5 ± 116.8, P < 0.01 left 109.8 ± 15.7 vs 101.7 ± 18.7, P < 0.05) and Achilles tendon moment arm shorter in HB (right, 3.4 ± 0.4 vs 3.6 ± 0.4 cm, P < 0.05; left, 3.4 ± 0.5 vs 3.7 ± 0.4 cm, P < 0.01). Lower-limb injury prevalence was 8% in HB and 61% in HS. HB subjects spent more time engaged in moderate to vigorous physical activity (60 ± 26 min·d vs 31 ± 13 min·d; P < 0.001). CONCLUSIONS: Significant differences observed in foot parameters, injury prevalence and general foot health between HB and HS suggest that footwear conditions may impact on foot structure and function and general foot health. HB children and adolescents spent more time engaged in moderate to vigorous physical activity and less time sedentary than HS children and adolescents.

Indirect methods such as the implicit association test (IAT) could complement traditional self-report questionnaires of personality traits. However, it is unclear whether IAT scores and self-report scores of nominally the same personality trait measure the same construct or overlapping but distinct constructs. To investigate how IAT and self-report personality scores relate to each other, we conducted a web-based data collection where participants completed self-report personality questionnaires (n = 432) and IATs for extraversion (n = 393) and neuroticism (n = 385). We found that extraversion self-report and IAT scores were more strongly correlated with each other than corresponding neuroticism scores. Overall, our findings suggest that although extraversion and neuroticism self-report and implicit measures are related, they do measure distinct constructs.

Subjective energy intake (sEI) is often misreported, providing unreliable estimates of energy consumed. Therefore, relating sEI data to health outcomes is difficult. Recently, Börnhorst et al. compared various methods to correct sEI-based energy intake estimates. They criticised approaches that categorise participants as under-reporters, plausible reporters and over-reporters based on the sEI:total energy expenditure (TEE) ratio, and thereafter use these categories as statistical covariates or exclusion criteria. Instead, they recommended using external predictors of sEI misreporting as statistical covariates. We sought to confirm and extend these findings. Using a sample of 190 adolescent boys (mean age=14), we demonstrated that dual-energy X-ray absorptiometry-measured fat-free mass is strongly associated with objective energy intake data (onsite weighted breakfast), but the association with sEI (previous 3-d dietary interview) is weak. Comparing sEI with TEE revealed that sEI was mostly under-reported (74 %). Interestingly, statistically controlling for dietary reporting groups or restricting samples to plausible reporters created a stronger-than-expected association between fat-free mass and sEI. However, the association was an artifact caused by selection bias – that is, data re-sampling and simulations showed that these methods overestimated the effect size because fat-free mass was related to sEI both directly and indirectly via TEE. A more realistic association between sEI and fat-free mass was obtained when the model included common predictors of misreporting (e.g. BMI, restraint). To conclude, restricting sEI data only to plausible reporters can cause selection bias and inflated associations in later analyses. Therefore, we further support statistically correcting sEI data in nutritional analyses. The script for running simulations is provided.

Objective The objective of this paper is to evaluate the behavioural effects, as reported by the parents of the participating boys and girls, of the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) intervention. Methods The effectiveness of the IDEFICS intervention was evaluated through a cluster-controlled trial in eight European countries (control and intervention communities in each country) including more than 16,000 children. The 2- to 9.9-year-old children in the intervention group were exposed to a culturally adapted intervention that aimed to prevent childhood obesity through the community, schools/kindergartens and family. Parents completed questionnaires to measure water, soft drink and fruit juice intake; fruit and vegetable intake; daily TV viewing and other sedentary behaviours; daily physical activity levels and strengthening of the parent–child relationships at baseline and follow-up (2 years later). Mixed models with an additional random effect for country were used to account for the clustered study design, and results were stratified by sex. Results The pan-European analysis revealed no significant time by condition interaction effects, neither for boys nor girls, i.e. the analysis revealed no intervention effects on the behaviours of the IDEFICS children as reported by their parents (F = 0.0 to 3.3, all p > 0.05). Also very few significances were found in the country-specific analyses. Positive intervention effects were only found for sport club participation in Swedish boys, for screen time in weekends for Spanish boys and for TV viewing in Belgian girls. Conclusion Although no expected intervention effects as reported by the parents on diet, physical activity and sedentary behaviours could be shown for the overall IDEFICS cohort, a few favourable intervention effects were found on specific behaviours in some individual countries. More in-depth analyses of the process evaluation data are needed to obtain more insight into the relationship between the level of exposure to the intervention and its effect

Background: The aim of this study was to explore whether the IDEFICS intervention had a differential effect on 11,041 children’s weight trajectories depending on their baseline body mass index status. Methods: Two subgroups of children are considered in the present analysis: those who were overweight or obese prior to the intervention and those who were neither overweight nor obese. Results: Among children in all eight countries who did not have prevalent overweight or obesity (OWOB) at baseline, 2 years later, there was no significant difference between intervention and control groups in risk of having developed OWOB. However, we observed a strong regional heterogeneity, which could be attributed to the presence of one distinctly outlying country, Belgium, where the intervention group had increased risk for becoming overweight. In contrast, among the sample of children with prevalent OWOB at baseline, we observed a significantly greater probability of normalized weight status after 2 years. In other words, a protective effect against persistent OWOB was observed in children in intervention regions compared with controls, which corresponded to an adjusted odds ratio of 0.76 (95% confidence interval: 0.58, 0.98). Discussion: This analysis thus provided evidence of a differential effect of the IDEFICS intervention, in which children with overweight may have benefited without having been specifically targeted. However, no overall primary preventive effect could be observed in children without initial overweight or obesity.

Objectives The primary aim of the present study was to obtain insight into parents' perception of the IDEFICS intervention at the school or preschool/kindergarten and community levels and whether they received specific materials related to the intervention. The secondary aim was to analyse whether parents who reported higher levels of exposure to the IDEFICS intervention had children with more favourable changes in body mass index (BMI) z-scores between baseline and after 2 years of intervention. Methods Process evaluation of the IDEFICS intervention investigated the implementation of the 2-year intervention in the intervention communities. Intervention group parents (n = 4,180) in seven countries (Belgium, Cyprus, Estonia, Germany, Italy, Spain and Sweden) answered questions about their exposure to the IDEFICS study. To analyse the relationship between exposure and BMI z-score, a composite score was calculated for exposure at the setting and at the community levels. Results The frequency of parental exposure to the IDEFICS messages not only through the community but also through the (pre)school/kindergarten was lower than what was intended and planned. The dose received by the parents was considerably higher through the (pre)school/kindergarten settings than that through the community in all countries. Efforts by the settings or communities related to fruit and vegetable consumption (range 69% to 97%), physical activity promotion (range 67% to 91%) and drinking water (range 49% to 93%) were more visible and also realized more parental involvement than those related to TV viewing, sleep duration and spending time with the family (below 50%). Results showed no relation of parental exposure at the setting or the community level on more favourable changes in children's BMI z-scores for the total sample. Country-specific analyses for parental exposure at the setting level showed an expected positive effect in German girls and an unexpected negative effect in Italian boys. Conclusion Parental exposure and involvement in the IDEFICS intervention in all countries was much less than aimed for, which might be due to the diverse focus (six key messages) and high intensity and duration of the intervention. It may also be that the human resources invested in the implementation and maintenance of intervention activities by the study centres, the caretakers and the community stakeholders were not sufficient. Higher levels of parental exposure were not related to more favourable changes in BMI z-scores.

Summary Background According to recent findings, short sleep duration is associated with overweight in children. However, primary prevention efforts aimed at achieving adequate sleep among children are scarce. Therefore, the ‘Identification and prevention of Dietary-induced and lifestyle-induced health EFfects In Children and infantS’ (IDEFICS) study implemented a multilevel intervention that included sleep duration as a key behavioural target. The aim of this study is to evaluate sleep duration among children participating in the IDEFICS study. Methods The IDEFICS nocturnal sleep intervention was included as part of stress reduction educational messages aimed at parents and children. Sleep was assessed by a parental 24-h recall (only weekdays; n = 8,543) and by a diary (weekdays and weekends separately; n = 4,150). Mixed linear models tested the intervention effect on sleep duration change between baseline when children were 2–9.9 years of age (2007/2008) and follow-up (2009/2010). Logistic mix models were used to study the intervention effect on the presence of TV in the children's bedroom (one of the intervention messages; n = 8,668). Additionally, parents provided qualitative data regarding exposure to the intervention. Results About 51.1% of the parents in the intervention regions reported awareness of the sleep intervention. A small intervention effect was seen on weeknight sleep duration in that the decrease in sleep duration over 2 years was smaller in the intervention (15 min) as compared with control regions (19 min) (p = 0.044). There was no overall intervention effect on weekend sleep duration or on the presence of a TV in the bedroom. A small significant time effect between baseline and follow-up was found on bedroom TV presence depending on self-reported intervention exposure (3% increase in TV presence in exposed versus 6.6% increase in non-exposed). Children without a TV in the bedroom had longer nocturnal sleep duration. Discussion The sleep component of the intervention did not lead to clinically relevant changes in sleep duration. Future interventions aimed at young children's sleep duration could benefit from more specific and intense messaging than that found in the IDEFICS intervention. Future research should use objective measures of sleep duration as well as intermediate outcomes (sleep knowledge, sleep environment and sleep practices).

This paper reports on the effectiveness of the prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) intervention on objectively measured physical activity (PA) and sedentary time (ST) in 2- to 9.9-year-old European boys and girls. METHODS: The intervention was evaluated after 2 years through a non-randomized cluster-controlled trial in eight European countries (one control and one intervention community per country). All children in the intervention group received a culturally adapted childhood obesity prevention programme through the community, schools/kindergartens and family. A random sub-sample of children participating in the IDEFICS study wore an accelerometer at baseline and follow-up for at least 3 days (n = 9,184). Of this sample, 81% provided valid accelerometer data at baseline (n = 7,413; 51% boys; 6.21 ± 1.76 years; boys: 617 ± 170 cpm day(-1) ; girls 556 ± 156 cpm day(-1) ) and 3,010 children provided valid accelerometer data at baseline and during the follow-up survey 2 years later. RESULTS: In boys and girls, no significant differences in PA and ST were found between intervention and control groups over 2 years. Strong temporal effects were found in the total sample of boys and girls: the percentage of time spent in light PA per day decreased by 4 percentage points in both boys and girls between baseline and follow-up (both: p < 0.001), while time spent in ST per day increased by 4 percentage points in both sexes over time (both: p < 0.001). Percentage of time spent in moderate-to-vigorous PA per day remained stable over time in boys and girls. CONCLUSION: Despite the socio-ecological approach and implementation of a culturally adapted intervention in each country, no effects of the IDEFICS intervention were found on children's objectively measured PA and ST. Behavioural interventions for children may need to enhance specificity and intensity at the family level using other behaviour change techniques and more direct strategies to reach parents.

Accurate assessment of physical activity (PA) is important to study the associations between PA and health outcomes, to evaluate the effectiveness of interventions and to derive public health recommendations. Despite limitations, accelerometry-based methods generate the best available measures for epidemiological research involving a large number of children and adults. In this chapter, we review the most important methodological issues pertaining to the use of accelerometers to assess the overall volume of PA. We stress the importance of recording and keeping the raw data whenever possible. We review the validation studies using accelerometry to determine energy expenditure and calibration studies that attempt to derive thresholds (“cut-offs”) for differentiating between activity intensity categories. Conceptual and measurement issues due to the use of different thresholds are reviewed, as well as the temporal resolution issues such as sampling rate and epoch length. Different wear time detection algorithms and inclusion criteria are reviewed as well as options in data reduction (deriving meaningful variables from accelerometer data). We present an R package automatising most of the steps in accelerometer data analysis. The chapter concludes with some insights into the future of accelerometry given the wearable revolution and logistical considerations in using accelerometers in large field studies.

Introduction Physical activity (PA) is one of the most important lifestyle behaviors to reduce the risk for non-communicable diseases. Positive effects of the urban environment on PA in terms of walkability measures such as street connectivity, land use mix, and availability of public open spaces in the urban neighborhood are well investigated. However, evidence of this association is mostly based on cross-sectional studies. Usually, discrete measures of urban point characteristics such as the simple intensity are calculated based on arbitrary municipal districts inducing scaling bias. The present study aims to longitudinally investigate the effect of built environment characteristics on PA of children in their transition phase to adolescence. We considered a kernel intensity approach to assess built environment characteristics and linked urban measures with objectively measured PA data that were collected in the IDEFICS/I.Family cohort. Methods Spatial data were collected in six study regions of three countries, Germany, Italy, and Sweden, participating in the IDEFICS/I.Family cohort. We considered walkability measures such as population density, land use mix (LUM), street connectivity, and availability of public transit. We additionally assessed the availability of public open spaces (POS). Point characteristics, e.g. intersections or POS, were assessed via adaptive anisotropic kernel functions. Urban measures were calculated in network-dependent home neighborhoods using a network distance of 1 km. We used standardized z-scores of urban measures to construct a moveability index that quantifies urban opportunities for PA of children and adolescents. Based on the place of residence, we linked urban measures with individual-level data of 699 children aged 2 to 14, who provided at least two (n = 610) or three (n = 89) accelerometer measurements, from either baseline, first follow-up (IDEFICS study), or second follow-up (I.Family study) with in total 1487 observations. Trajectories of moderate-to-vigorous physical activity (MVPA) as well as light physical activity (LPA) were modelled using linear mixed models accounting for repeated measurements nested within individuals by means of a random intercept and random linear slope for age (centred at 8 years). Environmental variables (z-scores) were included as fixed effects and as interaction effect with age. All models were stratified by sex and adjusted for age, BMI z-score, parental education, valid wear time, season, and region. Results Mean age was 6.6 in boys and 6.8 in girls. Compared to boys, girls spent on average less minutes in MVPA (boys: 58.8, girls: 51.6) and LPA (boys: 305, girls: 294) per day. Linear trajectories showed a significant decline of MVPA over age (boys: = −2.9, 95%CI: [−3.5; − 2.3], girls: = −3.6, [4.1; − 3.0]) and LPA (boys: = −7.6, [−9.1; − 6.1], girls: = −7.6, [−9.1; − 6.1]). The moveability index interacting with age showed only small effects on PA trajectories that were more pronounced for MVPA in boys (= 0.08, [−0.08;0.24]) and for LPA in girls (= 0.15, [−0.23;0.50]). Considering POS a stronger interaction with age was found for MVPA in boys (= 0.24, [−0.30; 0.78]) than in girls (= −0.08, [−0.58; 0.42]). The interaction of population density with age showed a positive effect on MVPA in boys, but not in girls, while the effect on LPA was stronger in girls compared to boys. Only in Girls, negative effects were found for LUM on MVPA (= −0.22, [−0.76; 0.33]) and LPA (= −1.14, [−2.52; 0.23]). Conclusion The kernel approach allowed for a flexible modelling of urban measures and improved the assessment compared to simple density methods. Although PA strongly declined with age, urban measures showed a supportive effect that attenuated this decline in the transition phase from childhood to adolescence. However, urban measures differently affected PA in boys and girls.

The associations between subjective ratings and objectively measured moderate-to-vigorous physical activity (MVPA) were examined in normal, and overweight and obese, pubertal boys and compared with their parents' reports. In total, 224 boys (M age = 12.2 yr.) completed the self-report questionnaire and wore an accelerometer for 7 consecutive days. Questionnaire-based indexes of physical activity (PA) were weakly associated with the accelerometer PA data. Correlations between subjective and objective assessments were significantly higher in overweight and obese groups. Parent reports predicted sedentary time better than boys' self-reports but no difference was found for MVPA. Future studies must consider that the source of rating, season, and weight status may be possible sources of confounding when using subjective assessments of PA.

We examined the tracking of physical activity (PA) measured by accelerometers and subjective self- and parental reports in normal weight and overweight and obese pubertal boys over two-year period. In total, 156 boys with mean (±SD) age of 11.53 ± 0.76 at baseline and with mean age of 13.94 ± 0.74 at 2 year follow-up were studied. At baseline and approximately two years later, the boys completed self-report questionnaire and wore an accelerometer for seven consecutive days. On the basis of first year assessment's body mass index (BMI), the children were grouped as normal weight and overweight and obese groups according to BMI cut-offs. Tracking correlations of objectively measured PA and subjectively measured PA were fairly similar across the 12-14 year-old-boys weight groups over two year period. Tracking correlations of objectively measured PA and subjectively measured PA were not significantly different over two-year period between both BMI groups. The results of the study show that pubertal boys objectively measured PA decreased over two-year period and so the boys started to be less active in their pubertal period.

Background/objectives High blood pressure (HBP) is one of the most important risk factors for cardiovascular diseases and it has a high prevalence in pediatric populations. However, the determinants of the incidence of Pre-HBP and HBP in children are not well known. i) To describe the incidence of HBP in European children; and ii) to evaluate the effect of physical activity (PA) and sedentary behavior (SB) on the Pre-HBP and HBP. Methods The IDEFICS cohort study. A total of 16,228 children 2–9years at baseline were recruited by complex sampling population-based survey in eight European countries. At baseline (T0), 5221 children were selected for accelerometer measurements; 5061 children were re-examined 2years later (T1). We estimated the incidence of Pre-HBP and HBP and evaluate the effect of PA and SB on the Pre-HBP and HBP, by computing relative risks and the corresponding 95% confidence intervals (RR, 95% CI). Results Incidences of Pre-HBP and HBP per year were: 121/1000 children and 110/1000 children, respectively. We found that children maintaining SB>2h/d during the two year follow-up showed a RR of having HBP of 1.28 (1.03–1.60). Children in T1 not performing the recommended amount of PA ( Conclusion The incidence of pre-HBP and HBP is high in European children. Maintaining sedentary behaviors during childhood increases the risk of developing HBP after two years of follow-up.

This study analyzes peer effects on childhood obesity using data from the first two waves of the IDEFICS study, which applies several anthropometric and other measures of fatness to approximately 14,000 children aged two to nine participating in both waves in 16 regions of eight European countries. Peers are defined as same-sex children in the same school and age group. The results show that peer effects do exist in this European sample but that they differ among both regions and different fatness measures. Peer effects are larger in Spain, Italy, and Cyprus - the more collectivist regions in our sample - while waist circumference generally gives rise to larger peer effects than BMI. We also provide evidence that parental misperceptions of their own children's weight goes hand in hand With fatter peer groups, supporting the notion that in making such assessments, parents compare their children's weight with that of friends and schoolmates. (C) 2015 Elsevier B.V. All rights reserved.

Self-report measures of physical activity (PA) are easy to use and popular but their reliability is often questioned. Therefore, the general aim of the present study was to investigate the association of PA questionnaires with accelerometer derived PA, in a sample of adolescent boys. In total, 191 pubertal boys (mean age 14.0 years) completed three self-report questionnaires and wore an accelerometer (ActiGraph GT1M) for 7 consecutive days. The PA questionnaires were: International Physical Activity Questionnaire-Short Form (IPAQ-SF), Tartu Physical Activity Questionnaire (TPAQ), and the Inactivity subscale from Domain-Specific Impulsivity (DSI) scale. All three questionnaires were significantly correlated with accelerometer derived MVPA: the correlations were 0.31 for the IPAQ-SF MVPA, 0.34 for the TPAQ MVPA and -0.29 for the DSI Inactivity scale. Nevertheless, none of the questionnaires can be used as a reliable individual-level estimate of MVPA in male adolescents. The boys underreported their MVPA in IPAQ-SF as compared to accelerometer-derived MVPA (respective averages 43 and 56 minutes); underreporting was more marked in active boys with average daily MVPA at least 60 minutes, and was not significant in less active boys. Conversely, MVPA index from TPAQ overestimated the MVPA in less active boys but underestimated it in more active boys. The sedentary time reported in IPAQ-SF was an underestimate as compared to accelerometer-derived sedentary time (averages 519 and 545 minutes, respectively).

The aim of this study was to construct a short, 30-item personality questionnaire that would be, in terms of content and meaning of the scores, as comparable as possible with longer, well-established inventories such as NEO PI-R and its clones. To do this, we shortened the formerly constructed 60-item "Short Five" (S5) by half so that each subscale would be represented by a single item. We compared all possibilities of selecting 30 items (preserving balanced keying within each domain of the five-factor model) in terms of correlations with well-established scales, self-peer correlations, and clarity of meaning, and selected an optimal combination for each domain. The resulting shortened questionnaire, XS5, was compared to the original S5 using data from student samples in 6 different countries (Estonia, Finland, UK, Germany, Spain, and China), and a representative Finnish sample. The correlations between XS5 domain scales and their longer counterparts from well-established scales ranged from 0.74 to 0.84; the difference from the equivalent correlations for full version of S5 or from meta-analytic short-term dependability coefficients of NEO PI-R was not large. In terms of prediction of external criteria (emotional experience and self-reported behaviours), there were no important differences between XS5, S5, and the longer well-established scales. Controlling for acquiescence did not improve the prediction of criteria, self-peer correlations, or correlations with longer scales, but it did improve internal reliability and, in some analyses, comparability of the principal component structure. XS5 can be recommended as an economic measure of the five-factor model of personality at the level of domain scales; it has reasonable psychometric properties, fair correlations with longer well-established scales, and it can predict emotional experience and self-reported behaviours no worse than S5. When subscales are essential, we would still recommend using the full version of S5.

On behalf of the HELENA study group., [Background & aims]: Chronobiology studies periodic changes in living organisms and it has been proposed as a promising approach to investigate obesity. We analyze the association of the characteristics of the rest-activity rhythms with obesity, cardiorespiratory fitness and metabolic risk in adolescents from nine European countries. [Methods]: 1044 adolescents (12.5–17.5 y) were studied. Circadian health was evaluated by actigraphy with accelerometers (Actigraph GT1M). Characteristics of the daytime activity such as fragmentation (intradaily variability), estimated acrophase, and 10 h mean daytime activity index were obtained. Body composition was assessed using Bioelectrical-Impedance-Analysis, skinfold thickness, air-displacement-plethysmography and Dual-energy-X-ray-Absorptiometry. Cardiorespiratory fitness (VO) and metabolic risk were studied. [Results]: Highly fragmented activity rhythms were associated with obesity and central adiposity (P < 0.05). Obese adolescents had ∼3 times higher odds of having a high fragmentation of daytime activity compared to normal weight adolescents OR (95% CI) = 2.8 (1.170, 6.443). A highly fragmented rhythm was also related to lower cardiorespiratory fitness and higher metabolic risk (P < 0.05) so those adolescents classified as low fitness showed a significantly higher fragmentation of daytime activity than those included in the high fitness group (P < 0.0001). Other characteristics of the rhythms such as smaller 10 h daytime mean activity index and delayed estimated acrophase were also related to obesity and metabolic risk (P < 0.05). [Conclusions]: Our results indicate that the daily organization of the rest-activity cycle is more fragmented in obese and less fit adolescents and correlates with higher metabolic risk. This fact reinforces our hypothesis that disturbances in daily rhythms can be considered as sensitive markers of poorer adolescent's health., The HELENA project was supported by of the European Community Sixth RTD Framework Programme (Contract FOOD-CT-2005-007034). The data for this study were gathered under the aegis of the HELENA project and their further analysis was additionally supported by grants from the Spanish Ministry of Economy and Competitiveness (RYC-2010-05957; RYC-2011-09011), the Spanish Ministry of Health: Maternal, Child Health and Development Network (number RD08/0072) and the “Fondo Europeo de Desarrollo Regional (MICINN-FEDER)”. The analyses were additionally funded by the Spanish Ministry of Economy and Competitiveness (SAF2014-52480); by the Ministry of Economy and Competitiveness and the Instituto de Salud Carlos III – RETICEF (The Ageing and Frailty Cooperative Research Network, RD12/0043/0011) and the Ministry of Education and Science (SAF2013-49132-C2-1-R) and the Ministry of Economy and Competitiveness (IPT-2011-0833-900000), including FEDER co-funding.

The paucity of mindfulness-based interventions and research in Estonia motivated the development of an Estonian Mindful Attention Awareness Scale (MAAS). Unlike most languages, the Estonian language lacks a distinctive present tense. This provides a potential challenge for assessing mindfulness, a psychological construct characterized by present-moment awareness. We outline the process of overcoming linguistic differences during translation. The Estonian MAAS showed a single-factor structure and strong internal consistency. A cross-cultural comparison showed factorial invariance between the Estonian and the original scale. In an Estonian adult student sample, MAAS scores were invariant across genders and education levels, positively related to subjective well-being and self-esteem and inversely related to public self-consciousness and social anxiety. Item response theory analyses (IRT) revealed seven items of the Estonian version carrying most of the information load. We discuss how translating the MAAS into a unique linguistic context could inform an understanding of mindfulness itself.

The present study addresses stability and change in value consensus among ethnic Estonians and Russian-speaking minority in terms of the 10 value types defined by Schwartz, the nature of group differences, and the structure of value change. European Social Survey data from four rounds (in the years 2004, 2006, 2008, & 2010) about responses to a 21-item version of the Portrait Values Questionnaire were used. The authors expected a decrease in value consensus of ethnic Estonians and Russian-speaking minority after the “monument war” in 2007. The study found that value consensus has been in four rounds relatively stable, except a drop in 2006. Value priorities of ethnic Estonians and Russian-speaking minority in the youngest age group (under 20 years) diverged after 2004. Older people have bigger consensus than younger ones. As expected, ethnic Estonians placed more importance on values related to openness to change and self-transcendence, and less importance on conservation and self-enhancement. Older people considered values related to conservation and self-transcendence more important, but those related to openness to change and self-enhancement less important than younger people. Value change was related to belonging to majority or minority groups as well as the age and gender of respondents. The pattern of value change among ethnic Estonians followed, but among Russian-speaking minority differed from the theoretical model. The study shows that values of people in formative years are likely to be extremely sensitive to concrete historical events and their interpretation.

We examined Finns' and bilingual Swedish-Finns' stereotypes regarding personality differences between Finns and Swedish-Finns and compared them with their respective self-ratings. Stereotype ratings by both groups converged on depicting Swedish-Finns as having a more desirable personality. In-group bias also influenced stereotypes. Contrary to predictions based on the Stereotype Content Model, out-group stereotypes were not compensatory. Consistent with the kernel of truth hypothesis of national stereotypes, Swedish-Finns' aggregate self-ratings resembled their stereotype of personality differences between the two groups, and their personality self-ratings were more desirable than Finns' self-ratings. Tentatively suggesting the occurrence of cultural frame shifting, the resemblance between Swedish-Finns' self-ratings and their stereotype of Swedish-Finns was, although only marginally statistically significantly, somewhat stronger when the self-ratings were provided in Swedish.

To examine the relationship between physical activity and energy demands in children and adolescents with highly active lifestyles.Physical activity patterns of 30 rural Kenyan children and adolescents (14 ± 1 years, mean ± SD) with median body mass index (BMI) z-score = -1.06 [-3.29-0.67] median [range] were assessed by accelerometry over 1 week. Daily energy expenditure (DEE), activity-induced energy expenditure (AEE) and physical activity level (PAL) were simultaneously determined using doubly-labelled water (DLW). Active commuting to school was assessed by global positioning system.Mean DEE, AEE and PAL were 12.2 ± 3.4, 5.7 ± 3.0 MJ/day and 2.3 ± 0.6, respectively. A model combining body mass, average accelerometer counts per minute and time in light activities predicted 45% of the variance in DEE (p 0.05) with a standard error of DEE estimate of 2.7 MJ/day. Furthermore, AEE accounted for ∼47% of DEE. Distance to school was not related to variation in DEE, AEE or PAL and there was no association between active commuting and adiposity.High physical activity levels were associated with much higher levels of energy expenditure than observed in Western societies. These results oppose the concept of physical activity being stable and constrained in humans.

ObjectiveChildren may influence household spending through ‘pester power’. The present study examined pestering through parent–child food shopping behaviours in relation to children’s diet and weight status.DesignCross-sectional and prospective analyses drawn from the IDEFICS study, a cohort study of parents and their children. Children’s height and weight were measured and their recent diets were reported by parental proxy based on the Children’s Eating Habits Questionnaire-FFQ at baseline and 2-year follow-up. Parents also completed questionnaires at both time points about pestering, including whether the child goes grocery shopping with them, asks for items seen on television and is bought requested food items.SettingParticipants were recruited from eight European countries for the IDEFICS study (non-nationally representative sample).SubjectsStudy participants were children aged 2–9 years at enrolment and their parents. A total of 13 217 parent–child dyads were included at baseline. Two years later, 7820 of the children were re-examined.ResultsMost parents (63 %) at baseline reported ‘sometimes’ acquiescing to their children’s requests to purchase specific foods. Pestering was modestly associated with weight and diet. At baseline, children whose parents ‘often’ complied consumed more high-sugar and high-fat foods. Children who ‘often’ asked for items seen on television were likely to become overweight after 2 years (OR=1·31), whereas ‘never’ asking protected against overweight (OR=0·72).ConclusionsPestering was modestly related to diet and weight in cross-sectional, but not longitudinal analyses. Asking for items seen on television had the most robust relationships across child outcomes and over time.

A functional promoter polymorphism of the nitric oxide synthase 1 gene first exon 1f variable number tandem repeat (NOS1 ex1f-VNTR) is associated with impulsivity and related psychopathology. Facets of impulsivity are strongly associated with personality traits; maladaptive impulsivity with neuroticism; and adaptive impulsivity with extraversion. Both high neuroticism and low extraversion predict anxiety and depressive symptoms. The aim of the present study was to evaluate the effect of the NOS1 ex1f-VNTR genotype and possible interaction with environmental factors on personality, anxiety, and depressiveness in a population-representative sample. Short allele carriers had higher neuroticism and anxiety than individuals with the long/long (l/l) genotype. Male short/short homozygotes also had higher extraversion. In the face of environmental adversity, females with a short allele had higher scores of neuroticism, anxiety, and depressiveness compared to the l/l genotype. Males were more sensitive to environmental conditions when they had the l/l genotype and low extraversion. In conclusion, the NOS1 ex1f-VNTR influences personality and emotional regulation dependent on gender and environment. Together with previous findings on the effect of the NOS1 genotype on impulse control, these data suggest that NOS1 should be considered another plasticity gene, because its variants are associated with different coping strategies.

Konstabel, Aavik, and Allik (2006) have found that controlling for social desirability in self- and peer-reports of personality using NEO Personality Inventory results in higher consensus. We report a reanalysis of these data showing that a similar effect is achieved when factor scores are used instead of unit-weight scores. The factor scores were also closer to being orthogonal even though they were computed using the coefficients published in the questionnaire’s manual. These findings are interpreted in terms of a general evaluative bias that is more or less unique to each rater, as opposed to trait information that is largely consensual.

Havik, M., Jakobson, A., Tamm, M., Paaver, M., Konstabel, K., Uusberg, A., Allik, J., Oopik, V. & Kreegipuu, K. (2012). Links between self-reported and laboratory behavioral impulsivity. Scandinavian Journal of Psychology 53, 216–223. A major problem in the research considering impulsivity is the lack of mutual understanding on how to measure and define impulsivity. Our study examined the relationship between self-reported impulsivity, behavioral excitatory and inhibitory processes and time perception. Impulsivity – fast, premature, thoughtless or disinhibited behavior – was assessed in 58 normal, healthy participants (30 men, mean age 21.9 years). Self-reported impulsivity as measured by Adaptive and Maladaptive Impulsivity Scale (AMIS) and behavioral excitatory and inhibitory processes as measured by Stop Signal Task were not directly related. Time perception, measured by the retrospective Time Estimation Task, was related to both. The length of the perceived time interval was positively correlated to AMIS Disinhibition subscale and negatively to several Stop Signal Task parameters. The longer subjects perceived the duration to last, the higher was their score on Disinhibition scale and the faster were their reactive responses in the Stop Signal Task. In summary our findings support the idea of cognitive tempo as a possible mechanism underlying impulsive behavior.

The prevalence of childhood stress and psychosomatic and emotional symptoms (PES) has increased in parallel, indicating that adverse, stressful circumstances and PES in children might be associated. This study describes the prevalence of PES in European children, aged 4-11 years old, and examines the relationship among PES, negative life events (NLE) and familial or social adversities in the child's life. Parent-reported data on childhood adversities and PES was collected for 4, 066 children from 8 European countries, who participated in the follow-up survey of IDEFICS (2009-2010), by means of the 'IDEFICS parental questionnaire'. A modified version of the 'Social Readjustment Rating Scale', the 'KINDL Questionnaire for Measuring Health-Related Quality of Life in Children and Adolescents' and the 'Strengths and Difficulties Questionnaire' were incorporated in this questionnaire, as well as questions on socio-demographics, family lifestyle and health of the child. Chi-square analyses were performed to investigate the prevalence of PES among survey centres, age groups and sex of the child. Odds ratios were calculated to examine the childhood adversity exposure between PES groups and logistic regression analyses were conducted to investigate: (a) the contribution of the number and (b) the specific types of experienced adversities on the occurrence of PES. 45.7% of the children experienced at least one PES, with low emotional wellbeing during the last week being most frequently reported (38.2%). No sex differences were shown for the prevalence of PES (P = 0.282), but prevalence proportions rose with increasing age (P\0.001). Children with PES were more frequently exposed to childhood adversities compared to children without PES (e.g. 13.3 and 3.9% of peer problems and 25.4 and 17.4% of non-traditional family structure in the PES vs. no PES group, respectively, P\0.001). An increasing number of adversities (regardless of their nature) was found to gradually amplify the risk for PES (OR = 2.85, 95% CI = 1.98-4.12 for a number of C3 NLE), indicating the effect of cumulative stress. Finally, a number of specified adversities were identified as apparent risk factors for the occurrence of PES, such as living in a non-traditional family structure (OR = 1.52, 95% CI = 1.30-1.79) or experiencing peer problems (OR = 3.55, 95% CI = 2.73-4.61). Childhood adversities were significantly related to PES prevalence, both quantitatively (i.e. the number of adversities) and qualitatively (i.e. the type of adversity). This study demonstrates the importance and the impact of the child's family and social context on the occurrence of PES in children younger than 12 years old. © 2012 Springer-Verlag.

A new approach to the construction of short questionnaires is introduced: ‘comprehensive single items’ (CSI) are developed with the intention to match expert descriptions of a construct as closely as possible. Based on this idea, a 60–item questionnaire, the ‘Short Five’ (S5) is constructed for measuring 30 facets of the Five–Factor Model. Studies in Estonian, Finnish, English, and German showed that the S5 domain scales had correlations over 0.8 with their counterparts in longer questionnaires, and that the factor structure was similar to that of the normative US NEO–PI–R sample. The S5 can be recommended for large–scale studies where participants’ time is limited. The CSI approach can be successfully used in short scale development, in addition to more traditional methods. Copyright © 2011 John Wiley & Sons, Ltd.

Background:Urbanization affects lifestyles in the developing world but no studies have assessed the impact on objectively measured physical activity in children and adolescents from sub-Saharan Africa.Purpose:To compare objectively measured habitual physical activity, sedentary time, and indices of adiposity in adolescents from rural and urban areas of Kenya.Methods:Physical activity and sedentary time were assessed by accelerometry for 5 consecutive days in 97 (50 female and 47 male) rural and 103 (52 female and 51 male) urban adolescents (mean age 13 ± 1 years). Body Mass Index (BMI) and BMI z-scores were used to assess adiposity.Results:Rural males spent more time in moderate-to-vigorous intensity physical activity (MVPA) compared with urban males (68 ± 22 vs. 50 ± 17 min, respectively; P < .001). Similarly, Rural females spent more time in MVPA compared with urban females (62 ± 20 vs. 37 ± 20 min, respectively; P < .001). Furthermore, there were significant differences in daily sedentary time between rural and urban subjects. Residence (rural vs. urban) significantly (P < .001) influenced BMI z-score (R2 = .46).Conclusion:Rural Kenyan adolescents are significantly more physically active (and less sedentary) and have lower indices of adiposity compared with urban adolescents and this is a likely refection of the impact of urbanization on lifestyle in Kenya.

Background Built environment studies provide broad evidence that urban characteristics influence physical activity (PA). However, findings are still difficult to compare, due to inconsistent measures assessing urban point characteristics and varying definitions of spatial scale. Both were found to influence the strength of the association between the built environment and PA. Methods We simultaneously evaluated the effect of kernel approaches and network-distances to investigate the association between urban characteristics and physical activity depending on spatial scale and intensity measure. We assessed urban measures of point characteristics such as intersections, public transit stations, and public open spaces in ego-centered network-dependent neighborhoods based on geographical data of one German study region of the IDEFICS study. We calculated point intensities using the simple intensity and kernel approaches based on fixed bandwidths, cross-validated bandwidths including isotropic and anisotropic kernel functions and considering adaptive bandwidths that adjust for residential density. We distinguished six network-distances from 500 m up to 2 km to calculate each intensity measure. A log-gamma regression model was used to investigate the effect of each urban measure on moderate-to-vigorous physical activity (MVPA) of 400 2- to 9.9-year old children who participated in the IDEFICS study. Models were stratified by sex and age groups, i.e. pre-school children (2 to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${

Parents of 592 children between the age of 0 ; 8 and 1 ; 4 completed the Estonian adaptation of the MacArthur-Bates Communicative Development Inventory (ECDI Infant Form). The relationships between comprehension and production of different categories of words and gestures were examined. According to the results of regression modelling the production of object gestures and gestural routines was positively correlated with the use of all the word categories. Comprehension of common nouns was positively correlated to the production of common nouns and predicates, whereas the comprehension of predicates was negatively correlated to the production of common nouns and social terms. The older the children were the more they produced words from each category. Girls were reported to produce more social terms. First-born children had an advantage over later-born children in the production of common nouns. Maternal educational level was associated with the production of common nouns and predicates.