***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Effects of living without siblings and living with gr and parents on  overweight and obesity  may change with child ’s age . We aim ed to examine these effects from early childhood to school age at the national level in Japan . Subjects were 43,046 children born in Japan during two weeks in 2001 who were followed annually from 2.5 to 13 years of age in the Longitudinal Survey of Newborns in the 21st Century . We used measured body height and weight reported by participants at each survey and followed the criteria of the International Obesity Task Force to define overweight and obesity . R and om-effects logit models by sex , adjusted for time-varying and time-invariant covariates , assessed odds ratios of overweight and obesity for living without siblings and for living with gr and parents at each age . The likelihood of overweight and obesity was significantly higher at 8 years and older among children living without siblings , compared with those living with siblings , and odds ratios were highest at 11 years of age in boys ( 1.87 , 95 % confidence interval [ CI ] : 1.49 , 2.33 ) and at 10 and 13 years of age in girls ( 1.75 [ 95 % CI : 1.36 , 2.23 ] and 1.73 [ 95 % CI : 1.30 , 2.31 ] , respectively ) . It was also significantly higher at 5.5 years and older among children living with gr and parents , compared with those living without gr and parents , and odds ratios were highest at 10 and 13 years of age in boys ( 1.53 [ 95 % CI : 1.30 , 1.80 ] and 1.54 [ 95 % CI : 1.27 , 1.86 ] , respectively ) and at 11 years of age in girls ( 1.51 , 95 % CI : 1.24 , 1.84 ) . In Japan , living without siblings and living with gr and parents may increase the likelihood of overweight and obesity at 8 and 5.5 years and older , respectively . Child ’s age should be considered during formulation of strategies for prevention of overweight and obesity in these groups BACKGROUND The number of studies that focus on factors influencing the sport participation ( SP ) of children and adolescents is limited . The present study examines the associations between demographic [ age , gender and socio-economic status ( SES ) ] and socio-cultural factors ( SP of family , and peers and physical educator influences ) and the SP of children and adolescents . METHODS A r and om sample of 3352 Portuguese children/adolescents , 10 - 18 years , their parents and siblings was surveyed . The assessment of SP was based on a psychometrically established question naire . Multivariable logistic regression was used in data analysis . RESULTS ( i ) age was not related to children/adolescent 's SP ; ( ii ) children/adolescents with high SES ( OR:1.7 , 95%CI:1.4 - 2.2 ) and medium SES ( OR:1.4 , 95%CI:1.1 - 1.7 ) were more involved in sports ; ( iii ) children/adolescents were more likely to participate in sports when their family also participate ; ( iv ) boys were more likely to participate in sports than girls ( adjusted OR:3.3 , 95%CI:2.8 - 3.9 from a main effects model ) , but mother 's SP influenced their daughters and sons differently . Daughters showed a greater propensity for practising sports when their mothers did ( OR:2.5 ; 95%CI:1.7 - 3.6 ) . For sons , sports involvement was similar whether or not their mothers participated ( OR:1.1 ; 95%CI:0.7 - 1.7 ) ; ( v ) peers had a positive influence on the participants ' SP ( OR:2.2 , 95%CI:1.9 - 2.7 ) ; ( vi ) after adjusting for other factors , the influence of a physical education teacher was not found to affect the SP of the children/adolescents . CONCLUSION There are important demographic and socio-cultural influences on the SP of children/adolescents-in particular , gender , SES , family members ' SP and peer influence Background While the household context is important for lifestyle behavior interventions , few studies have examined parent – child associations for  diet and physical activity ( PA ) changes over time in a rapidly urbanizing country . We aim ed to investigate changes in  diet , screen time , and PA behaviors  over time in children and their parents living in the same household , and examine the parent – child association for these behaviors . Methods We studied  dietary , screen time , and PA behaviors  in 5,201 parent – child pairs ( children aged 7 - 17y ) using longitudinal data from the China Health and Nutrition Survey ( 1991 , 1993 , 1997 , 2000 , 2004 , 2006 , and 2009 ) . We collected three-day 24-h recall diet data to generate percentages of energy from animal- source foods , away-from-home eating , and snacking from 1991–2009 , which are known urbanization-related behaviors . We used a seven-day PA recall to collect screen time ( hours/week ) and leisure-time sports participation ( yes/no ) since 2004 . We examined the changes in children ’s and parents ’ behaviors over time using r and om-effects negative binomial regression for  diet and screen time  , and r and om-effects logistic regression for leisure-time sports . We then regressed each of the behaviors of offspring on each of their parents ’ same behaviors to examine the parent – child association , using the same set of models . Results We observed increases in energy from animal- source foods , eating away-from-home , and snacking , as well as screen time and leisure-time sports in parents and children over time , with different rates of change between children and their parents for some behaviors . We found positive parent – child associations for diet , screen time , and PA . When parental intakes increased by 10 % energy from each dietary behavior , children ’s increase in intakes ranged from 0.44 to 1.59 % total energy for animal- source foods , 0.17 % to 0.45 % for away-from-home eating , and 2.13 % to 7.21 % for snacking . Children were also more likely to participate in leisure-time sports if their parents participated in leisure-time sports . Conclusion Our findings support household-based health behavior interventions targeting both children and their parents . However , generation-specific intervention strategies may be needed for children and adults , especially for dietary behaviors , which changed differentially in children versus parents in this rapidly modernizing population BakckgroundThe first aim was to examine the effect of the UP4FUN pilot intervention on children ’s total sedentary time . The second aim was to investigate if the intervention had an effect on  children ’s physical activity ( PA ) level . Finally , we aim ed to investigate demographic differences ( i.e. age , gender , ethnicity , living status and having siblings ) between children in the intervention group who improved in sedentary time and PA at post-test and children in the intervention group who worsened in sedentary time and PA at post-test . Methods The six weeks UP4FUN intervention was tested in a r and omized controlled trial with pre-test post-test design with five intervention and five control schools in Belgium and included children of the 5th and 6th grade . The children wore accelerometers for seven days at pre- and post-test . Analyses included children with valid accelerometer data for at least two weekdays with minimum 10h-wearing time and one weekend day with 8h-wearing time . Result Final analyses included 372 children ( 60 % girls , mean age = 10.9 ± 0.7 years ) . There were no significant differences in the change in sedentary time or light PA between intervention and control schools for the total sample or for the subgroup analyses by gender . However , children ( specifically girls ) in the intervention group had a higher decrease in moderate-to-vigorous PA than children in the control group . In the intervention group , children who lived with both parents and children with one or more siblings were less likely to reduce sedentary time after exposure to the intervention . Older children , girls and children who lived with both parents were less likely to increase light PA after the intervention . Conclusion The UP4FUN intervention did not result in an effect on children ’s sedentary time . Based on the high amounts of accelerometer-derived sedentary time in this age group , more efforts are needed to develop strategies to reduce children ’s sedentary time Introduction Many children fail to meet international guideline recommendations for health-related activity ( ≥60 minutes/day of moderate-to-vigorous physical activity [ MVPA ] ) , and intervention studies to date have reported negligible effects . Objective Explore the associations of organized leisure-time sport participation with overall physical activity levels and health-related physical activity guideline concordance . Methods This prospect i ve cohort study was nested in the Childhood Health , Activity , and Motor Performance School Study Denmark . Study participants were a representative sample of 1124 primary school students .  Organized leisure-time sport participation was reported via text messaging and physical activity was objective ly measured over seven days with accelerometry . Associations between sport participation and physical activity level were explored with multilevel mixed-effects regression models and reported with beta coefficients ( b ) and adjusted odds ratios ( aOR ) . Results Participants were 53 % female , with mean(SD ) age = 8.4(1.4 ) years . Boys were more active than girls ( p<0.001 ) , and physical activity levels and guideline concordance decreased with age ( p<0.001 ) . Soccer participation at any frequency was associated with greater overall MVPA ( b[95 % CI ] = 0.66[0.20,1.13 ] to 2.44[1.44,3.44 ] ) . Depending on participation frequency , this equates to 5–20 minutes more MVPA on the average day and 3 to 15 fold increased odds of achieving recommended levels of health-related physical activity ( aOR[95%CI ] = 3.04[1.49,6.19 ] to 14.49[1.97,106.56 ] ) . Similar associations were identified among children playing h and ball at least twice per week . Relationships with other sports ( gymnastics , basketball , volleyball ) were inconsistent . Conclusions Many children , particularly girls and those in higher grade levels do not adhere to health-related physical activity recommendations . Organized leisure-time sport participation may be a viable strategy to increase overall health-related physical activity levels and international guideline concordance in children Background : Physical activity ( PA ) and sedentary time ( SED ) have both been suggested as potential risk factors for adiposity in children . However , there is paucity of data examining the temporal associations between these variables . Objective : This study aim ed to analyze the cross-sectional and prospect i ve associations between PA , SED and body composition in children . Methods : A total of 510 children ( age at baseline 10.1±0.8 , age at follow-up 11.8±0.9 ) from six Portuguese schools from the Oeiras Municipality participated in this study .  PA and SED were measured by accelerometry and trunk fat mass ( TFM ) and body fat mass ( BFM )  were measured by dual energy X-ray absorptiometry .  Fat mass index ( FMI ) was calculated as BFM divided by height squared . Several regression models adjusted for age , sex , maturity status , follow-up duration , baseline levels of the outcome variable and SED or moderate to vigorous PA ( MVPA ) were performed . Results : MVPA ( min per day ) was cross-sectionally inversely associated with adiposity indexes ( FMI , TFM and BFM ) . Adiposity indexes were inversely associated with time in MVPA . In prospect i ve analyses , MVPA was associated with a lower levels of FMI ( β=−0.37 , 95 % confidence interval ( CI ) : −0.49 to −0.26 , P<0.001 ) , TFM ( β=−0.20 , 95 % CI : −0.29 to −0.10 , P<0.001 ) and BFM ( β=−0.37 , 95 % CI : −0.49 to −0.26 , P<0.001 ) . When the model was adjusted for age , sex , maturity status and for baseline levels of the outcome variables MVPA remained a significant predictor of lower adiposity indexes ( FMI : β=−0.09 , 95 % CI : −0.16 to −0.01 , P<0.05 ; TFM : β=−0.08 , 95 % CI : −0.15 to −0.01 , P<0.05 ; BFM : β=−0.07 , 95 % CI : −0.15 to 0.00 , P<0.05 ) . Adiposity was not associated  with MVPA when modeled as the exposure in prospect i ve analyses . SED was not related with adiposity indexes , except for the relationship with FMI . Conclusions : In cross-sectional and prospect i ve analyses , MVPA is associated with lower adiposity independent of covariates and SED . Results suggest that promoting MVPA is important for preventing gain in adiposity in healthy children BACKGROUND : Concern has been raised regarding the increased prevalence of physical inactivity among children .  Active transportation , such as walking and cycling to school , is an opportunity for children to be physically active . OBJECTIVE : To identify the sociodemographic predictors of  active transportation to schools across time among school-aged children participating in the Canadian National Longitudinal Survey of Children and Youth ( NLSCY ) . METHODS : The 
    Output:
    
Findings were mixed for the influence of siblings on sedentary behaviour and light physical activity .
Summary / Conclusion Children with siblings  had healthier physical activity patterns , as measured by accelerometer or pedometer , than did only children .