Associations Between Screen-Based Sedentary Behavior and Cardiovascular Disease Risk Factors in Korean Youth Screen time, cardiorespiratory fitness and adiposity among school-age children from Monteria, Colombia. Association of dietary habits with levels of physical activity and screen time among adolescents living in Saudi Arabia. Impact of objectively measured sedentary behaviour on changes in insulin resistance and secretion over 3 years in the RISC study: interaction with weight gain. Objective vs. Self-Reported Physical Activity and Sedentary Time: Effects of Measurement Method on Relationships with Risk Biomarkers Accelerometer-measured sedentary time and physical activity-A 15 year follow-up of mortality in a Swedish population-based cohort. Extracurricular physical activity participation modifies the association between high TV watching and low bone mass. Sedentariness, small-screen recreation, and fitness in youth. Longitudinal sedentary behavior changes in adolescents in Ho Chi Minh City. Evaluation of the Web-based computer-tailored FATaintPHAT intervention to promote energy balance among adolescents: results from a school cluster randomized trial. Objectively Measured Moderate- and Vigorous-Intensity Physical Activity but Not Sedentary Time Predicts Insulin Resistance in High-Risk Individuals School-based intervention on healthy behaviour among Ecuadorian adolescents: effect of a cluster-randomized controlled trial on screen-time Objectively Measured Sedentary Time May Predict Insulin Resistance Independent of Moderate- and Vigorous-Intensity Physical Activity Sedentary behavior & health-related quality of life among congestive heart failure patients. Cross-sectional and prospective associations between moderate to vigorous physical activity and sedentary time with adiposity in children Correlates of preschool children’s objectively measured physical activity and sedentary behavior: a cross-sectional analysis of the SPLASHY study Investigating children's physical activity and sedentary behavior using ecological momentary assessment with mobile phones.
The purpose s of this study were to : 1 ) describe the patterns of screen-based sedentary behaviors  , and 2 ) examine the association between  screen-based sedentary behavior and cardiovascular disease ( CVD ) risk factors in representative Korean children and adolescents , aged 12 to 18 yr , in the Korean National Health and Nutrition Examination Survey .  Screen-based sedentary behavior  was measured using self-report question naires that included items for time spent watching TV and playing PC/video games . Physical activity  was measured using items for frequency and duration of moderate-to-vigorous physical activity ( MVPA )  . CVD risk factors such as body mass index ( BMI ) , waist circumference , LDL cholesterol , HDL cholesterol , total cholesterol , triglycerides , glucose , systolic blood pressure , and diastolic blood pressure were measured . Boys spent more time playing PC/video games , and girls spent more time watching TV . After adjusting for age , gender , annual household income , and MVPA , an additional hour of watching TV was significantly associated with the risk of overweight ( OR 1.17 [ 95 % CI 1.03 - 1.33 ] ) , high abdominal adiposity ( OR 1.27 [ 1.06 - 1.51 ] ) , and low HDL cholesterol ( OR 1.27 [ 1.10 - 1.47 ] ) . An additional hour spent playing PC/video games  also increased the risk of high abdominal adiposity ( OR 1.20 [ 1.03 - 1.40 ] ) . Prospect i ve observations and interventions are needed to determine causal relationships between  screen-based sedentary behavior  and CVD risk profiles in Korean youth OBJECTIVES To explore the association between electronic media exposure ( television viewing time , personal computer/video game use , total screen time ) , and waist circumference and body mass index , and study whether this association is independent of cardiorespiratory fitness , in a representative sample of adolescents from Montería , Colombia . DESIGN Cross-sectional study analyzing data from 546 students aged 11 - 18 years , from fourteen r and omly selected schools .  Z-scores for WC and BMI were calculated . METHODS The physical activity module of the Global School Health Survey 2007 was used to determine EME , and the shuttle run test was used to assess CRF . Linear regression models adjusted by age , school location , physical activity level , type of institution ( public or private ) , consumption of sweetened beverages , fast food , and fried food were used . RESULTS Among boys , independently of cardiorespiratory fitness , high television viewing time ( ≥ 2 h/day ) ( β=+0.22 ; p<0.02 ) , was positively associated with waist circumference . High total screen time ( > 3h/day ) was positively associated with waist circumference ( β=+0.34 ; p<0.01 ) , and body mass index ( β=+0.39 ; p<0.01 ) . Among girls , sedentary behavior was not associated with adiposity , but cardiorespiratory fitness ( β=-0.04 ; p<0.02 ) was negatively associated with body mass index . CONCLUSIONS These findings support the evidence on the negative impact of excessive electronic media exposure and low cardiorespiratory fitness , and highlight the need for interventions and prevention strategies BACKGROUND Underst and ing the inter-relationships between lifestyle factors in youth is important with respect to the development of effective promotional programmes for healthy eating and active living . The present study aim ed to explore the associations of dietary habits ( DH ) with physical activity ( PA ) and screen time ( ST )  among Saudi adolescents aged between 15 and 19 years of age relative to gender . METHODS Data were obtained from the Arab Teens Lifestyle Study , a school-based multicentre lifestyle study conducted in 2009/2010 in three major cities in Saudi Arabia . A multistage stratified cluster r and om sampling technique was used . The number of participants with complete data for  DH  and  PA  was 2886 and the respective number for DH and ST was 2822 . Assessment included weight , height , body mass index , total daily ST ( television viewing , video/computer games and Internet use ) , PA and DH using self-reported question naires . RESULTS Females were significantly more sedentary and less active than males ( P < 0.001 ) . Two-way analysis of covariance , controlling for age , showed significant ( P < 0.05 ) gender by PA and gender by ST interactions for several DH . Logistic regression analyses revealed significant associations of higher PA with a higher consumption of fruit , vegetables , milk , French fries/potato chips and energy drinks , whereas higher ST was significantly associated with a higher consumption of sugar-sweetened drinks , fast foods , cake/doughnuts and energy drinks . CONCLUSIONS Healthful dietary habits were associated mostly with  PA  , whereas sedentary behaviours , independent of PA , negatively impacted upon eating behaviours . The low PA levels and high sedentary levels of Saudi females represent a great concern . The results reported in the present study have important implication s for both youth public health policies and intervention programmes AIMS The importance of reducing sedentary time is increasingly being recognized in the prevention of diabetes and cardiovascular disease . Despite this , the prospect i ve association between sedentary time and physical activity with insulin sensitivity and cardiometabolic risk factors has been little studied . METHODS In an analysis of data from the European RISC study , sedentary time and time spent in activity of moderate or vigorous intensity were assessed by accelerometry at baseline in 313 men and 414 women , aged 30 - 60 years , with insulin sensitivity as measured by euglycaemic-hyperinsulinaemic clamp . Three years later , cardiometabolic risk factors ( anthropometry , glucose , insulin , lipids ) were available for 549 participants . RESULTS In cross-sectional analyses using baseline data , after adjusting for age , gender , recruitment centre and time spent in activity of moderate or vigorous intensity , significant unfavourable associations were observed between higher sedentary time with body weight , HDL cholesterol , triglycerides , clamp-measured insulin sensitivity and insulin secretion ( all P(trend)<0.002 ) .  Sedentary time  remained significantly associated with insulin secretion after adjusting for insulin sensitivity ( P(trend)=0.02 ) . In longitudinal analyses , higher baseline sedentary time  was associated with 3-year increases in fasting glucose , fasting insulin and the HOMA insulin-resistance index score for the 50 % of the study population who increased their BMI by at least 0.3 kg/m(2 ) ( all P(trend)<0.01 ) ; these relationships remained significant after adjusting for time spent in activity of moderate or vigorous intensity . The 3-year increase in insulin secretion was lower in those spending more time doing activity of moderate or vigorous intensity ( P(trend)=0.03 ) . CONCLUSION These prospect i ve data suggest that less sedentary behaviour may partly counteract some of the negative effects of increasing body weight on glucose-insulin homoeostasis Purpose Imprecise measurement of physical activity variables might attenuate estimates of the beneficial effects of activity on health-related outcomes . We aim ed to compare the cardiometabolic risk factor dose-response relationships for physical activity and sedentary behaviour between accelerometer- and question naire-based activity measures . Methods  Physical activity and sedentary behaviour  were assessed in 317 adults by 7-day accelerometry and International Physical Activity Question naire ( IPAQ ) . Fasting blood was taken to determine insulin , glucose , triglyceride and total , LDL and HDL cholesterol concentrations and homeostasis model-estimated insulin resistance ( HOMAIR ) . Waist circumference , BMI , body fat percentage and blood pressure were also measured . Results For both accelerometer-derived sedentary time ( < 100 counts.min−1 ) and IPAQ-reported sitting time significant positive ( negative for HDL cholesterol ) relationships were observed with all measured risk factors – i.e. increased sedentary behaviour was associated with increased risk ( all p≤0.01 ) . However , for HOMAIR and insulin the regression coefficients were > 50 % lower for the IPAQ-reported compared to the accelerometer-derived measure ( p<0.0001 for both interactions ) . The relationships for moderate-to-vigorous physical activity ( MVPA ) and risk factors were less strong than those observed for sedentary behaviours , but significant negative relationships were observed for both accelerometer and IPAQ MVPA measures with glucose , and insulin and HOMAIR values ( all p<0.05 ) . For accelerometer-derived MVPA only , additional negative relationships were seen with triglyceride , total cholesterol and LDL cholesterol concentrations , BMI , waist circumference and percentage body fat , and a positive relationship was evident with HDL cholesterol ( p = 0.0002 ) . Regression coefficients for HOMAIR , insulin and triglyceride were 43–50 % lower for the IPAQ-reported compared to the accelerometer-derived MVPA measure ( all p≤0.01 ) . Conclusion Using the IPAQ to determine sitting time and MVPA reveals some , but not all , relationships between these activity measures and metabolic and vascular disease risk factors . Using this self-report method to quantify activity can therefore underestimate the strength of some relationships with risk factors OBJECTIVES To investigate the associations of objective ly assessed sedentary time , light intensity physical activity ( PA ) , moderate to vigorous intensity PA ( MVPA ) , and total PA with all-cause mortality and mortality from cardiovascular disease ( CVD ) or cancer in a Swedish population -based cohort with 15 years follow-up time . DESIGN Longitudinal prospect i ve cohort study . METHODS Data from 851 persons ( 56 % women ) ≥35 years at baseline were included . Primary exposure variables were  time ( min/day ) spent sedentary , in light intensity PA and in MVPA , and total counts from an Actigraph 7164 accelerometer . Data on all-cause mortality and mortality from CVD or cancer were obtained from Swedish registers . Cox proportional hazards models estimated hazard ratios ( HR ) of mortality with 95 % confidence intervals ( CI ) . RESULTS Compared with the least sedentary participants , those in the most sedentary tertile had an increased risk of all-cause mortality , HR : 2.7 ( 1.4 , 5.3 ) , CVD mortality , HR : 5.5 ( 1.4 , 21.2 ) and cancer mortality , HR : 4.3 ( 1.2 , 16.0 ) . For all-cause mortality , those in the highest light intensity PA tertile had a HR 0.34 ( 0.17 , 0.67 ) compared with the lowest tertile . A similar pattern was found for CVD and cancer mortality . More time spent in MVPA was associated with the largest risk reduction for CVD mortality , with an almost 90 % lower risk in the tertile with the most time in MVPA . CONCLUSIONS This study confirms a strong inverse relationship between MVPA and mortality , and adds new insight for the underst and ing of the associations between sedentary time  and light intensity PA  and mortality OBJECTIVES To examine whether different sedentary behaviours are associated with the risk of  low bone mineral content in adolescents , and if so , whether extracurricular physical-sporting activity influences this association . MATERIAL S AND METHODS A total of 277 adolescents from Zaragoza ( 168 females and 109 males ) aged 13.0 - 18.5 yr within frame work of the multicentre AVENA study participated in this study . Bone mineral content ( BMC ) , lean mass , and fat mass were measured with DXA . Physical activity and sedentary independent variables : participation in extracurricular physical-sporting activity ( PA ) , h/d of television watching , playing video/computer games during school days and on weekend days and doing homework/ study ing . They all were assessed by question naire . The main outcome was low BMC , as defined by BMC Z-score for age and sex < percentile 10 . Logistic regression was used to test the interaction and association of PA and sedentary variables with low BMC , after controlling for confounders like height , maturational status or lean mass . RESULTS Among the sedentary variables studied , only television watching > or =3 h/d was associated with an increased risk for low BMC in males ( OR , 95 % CI : 7.01 , 1.73 to 28.40 ) , after controlling for sexual maturation . When PA was in the models , television watching was not any longer associated with low BMC , while PA was so ( OR , 95 % CI : 0.23 , 0.09 to 0.55 ) . Involvement in such activity reduced the risk of low bone mass by 76 % ( P<0.01 ) independently of body mass , height and fat mass , but not of the lean mass . CONCLUSION Watching television for 3 or more h/d seems to be associated with an increased risk for  low BMC in male adolescents . However , this association is mediated by participation in PA , suggesting that negative consequences of excessive television watching on adolescent bone health could be counteracted by sport participation . Longitudinal data and r and omized controlled trials will confirm or contrast our findings BACKGROUND There are concerns that sedentariness among young people has increased and that this may be detrimental to their health . The purpose of this study was to examine the association between sedentary activities , including  small-screen recreation ( SSR : watching TV/DVDs/videos , recreational computer use ) and cardiorespiratory endurance ( CRE ) in children aged 11 - 15 years . METHODS A cross-sectional representative population survey was taken of New South Wales ( Australia ) school students in Grade s 6 , 8 , and 10 ( N=2750 ) in 2004 .  Sedentary activities and SSR were measured by a self-report question naire .  CRE was determined by the 20-meter multi-stage shuttle run test . The optimal cut point for time spent on SSR was determined by receiver operating characteristic analysis . RESULTS Time spent in sedentary activities was inversely associated with CRE among Grade 8 students ( p=0.01 ) and Grade 10 girls ( p=0.03 ) . CRE was lower among Grade 8 students ( p<0.001 ) and Grade 10 girls ( p<0.001 ) who spent > or=2 hours/day on SSR compared with students who spent < 2 hours/day . The 2-hour/day cut point for SSR had high sensitivity ( boys : 84 % , [ 95 % CI=79 % , 87 % ] ; girls : 79 % [ 95 % CI=74 % , 84 % ] ) and low specificity ( boys : 28 % [ 95 % CI=24 % , 32 % ] ; girls : 42 % [ 95 % CI=38 % , 46 % ] ) . CONCLUSIONS Cardiorespiratory endurance did not differ consistently across quintiles of sedentariness and SSR among boys ; however , among girls there was a consistent inverse association . If confirmed in prospect i ve studies , these findings have important implication s for risk of chronic disease BACKGROUND Sedentary behavior is associated with increased risk of chronic disease and sedentary behavior is increasing among adolescents . Data on changes in sedentary behavior in developing countries are limited . PURPOSE To describe 5-year longitudinal changes in nonschool sedentary hours among urban adolescents in Ho Chi Minh City , and to identify correlates with this change . METHODS This is a 5-year longitudinal cohort with systematic r and om sampling of 759 students from 18 junior high schools . All measures were taken annually between 2004 and 2009 .  Sedentary behavior  was assessed by self-report and accelerometry . Generalized linear latent and mixed models were used to analyze the data in 2011 . RESULTS Between 2004 and 2009 , self-reported time spent in nonschool sedentary behavior  increased from 498 to 603 minutes/day . In the 5th survey year , boys and girls ( aged 16 years ) were , respectively , 3.6 times ( 95 % CI=2.3 , 6.0 ) and 3.1 times ( 95 % CI= 1.8 , 5.0 ) more likely to spend ≥2 hours/day on screen time compared with baseline ( aged 12 years ) . Accelerometer data adjusted for wearing time revealed that boys and girls aged 16 years had , respectively , 78 minutes/day ( 95 % CI=48 , 104 ) and 69 minutes/day ( 95 % CI=34 , 95 ) more nonschool sedentary time than those at the first accelerometer assessment ( at age 13 years ) . Girls in the highest socioeconomic quartile spent an additional 90 minutes/day in sedentary behavior compared with girls in the lowest quartile ( 95 % CI=52 , 128 ) .  CONCLUSIONS Nonschool sedentary behavior  increased among Vietnamese adolescents with age . The largest increase was in recreational screen time ( 28 % ) , which would be the most obvious target for preventive health strategies OBJECTIVE To evaluate the short- and long-term results of FATaintPHAT , a Web-based computer-tailored intervention aim ing to increase physical activity , decrease sedentary behavior , and promote healthy eating to contribute to the prevention of excessive weight gain  among adolescents . DESIGN Cluster r and omized trial with an intervention group and a no-intervention control group . SETTING Twenty schools in the Netherl and s. PARTICIPANTS A total of 883 students ( aged 12 - 13 years ) . INTERVENTION The FATaintPHAT ( VETisnietVET in Dutch ) Web-based computer-tailored intervention . OUTCOME MEASURES Self-reported behaviors ( diet , physical activity , sedentary behavior ) and pedometer counts were measured at baseline and at 4-month and 2-year follow-up ; body mass index ( BMI ) , waist circumference , and fitness were measured at baseline and at 2-year follow-up . Descriptive and multilevel regression analyses were conducted among the total study population and among students not meeting behavioral recommendations at baseline ( students at risk ) . RESULTS The complete case analyses showed that FATaintPHAT had no effect on BMI and waist circumference . However , the intervention was associated with lower odds ( 0.54 ) of drinking more than 400 mL of sugar-sweetened beverages per day and with lower snack intake ( β = -0.81 snacks/d ) and higher vegetable intake ( β = 19.3 g/d ) but also with a lower step count ( β = -10 856 steps/wk ) at 4-month follow-up . In addition , among students at risk , FATaintPHAT had a positive effect on fruit consumption ( β = 0.39 g/d ) at 4-month follow-up and on step count ( β = 14 228 steps/wk ) at 2-year follow-up but an inverse effect on the odds of sports participation ( odds ratio , 0.45 ) at 4-month follow-up . No effects were found for sedentary behavior . CONCLUSION The FATaintPHAT intervention was associated with positive short-term effects on diet but with no effects or unfavorable effects on physical activity and sedentary behavior OBJECTIVE Low levels of physical activity appear to be associated with insulin resistance . However , the detailed associations of these complex relationships remain elusive . We examined the prospect i ve associations between self-reported TV viewing time , objective ly measured time spent sedentary , at light-intensity activity , and at moderate- and vigorous-intensity physical activity ( MVPA ) with insulin resistance . RESEARCH DESIGN AND METHODS In 192 individuals ( 81 men and 111 women ) with a family history of type 2 diabetes , we measured  physical activity and anthropometric and metabolic variables at baseline and after 1 year of follow-up in the ProActive UK trial . Physical activity  was measured objective ly by accelerometry . Insulin resistance was expressed as fasting insulin and the homeostasis model assessment score ( HOMA-IR ) . RESULTS Baseline MVPA was a significant predictor of fasting insulin at follow-up ( β = −0.004 [ 95 % CI −0.007 to −0.0001 ] , P = 0.022 ) , and the association approached significance for HOMA-IR ( β = −0.003 [ −0.007 to 0.000002 ] , P = 0.052 ) , independent of time spent sedentary , at light-intensity activity , sex , age , smoking status , waist circumference , and self-reported TV viewing . Time spent sedentary and at light-intensity activity were not significantly associated with insulin resistance . The change in MVPA between baseline and follow-up was inversely related to fasting insulin ( β = −0.003 [ −0.007 to −0.0003 ] , P = 0.032 ) and the HOMA-IR score ( β = −0.004 [ −0.008 to −0.001 ] , P = 0.015 ) at follow-up , after adjustment for baseline phenotype in addition to the same confounders as above . CONCLUSIONS These results highlight the importance of promoting moderate-intensity activity such as brisk walking for improving insulin sensitivity and possibly other metabolic risk factors to prevent type 2 diabetes Background Effective interventions on screen-time behaviours ( television , video games and computer time ) are needed to prevent non-communicable diseases in low- and middle-income countries . The present manuscript investigates the effect of a school-based health promotion intervention on screen-time behaviour among 12- to 15-year-old adolescents . We report the effect of the trial on screen-time after two stages of implementation . Methods We performed a cluster-r and omised pair matched trial in urban schools in Cuenca-Ecuador . Participants were adolescents of grade eight and nine ( mean age 12.8 ± 0.8 years , n = 1370 , control group n = 684 ) from 20 schools ( control group n = 10 ) . The intervention included an individual and environmental component tailored to the local context and re sources . The first intervention stage focused on diet , physical activity and screen-time behaviour , while the second stage focused only on diet and physical activity .  Screen-time behaviours , primary outcome , were assessed at baseline , after the first ( 18 months ) and second stage ( 28 months ) . Mixed linear models were used to analyse the data . Results After the first stage ( data from n = 1224 adolescents ; control group n = 608 ) , the intervention group had a lower increase in TV-time on a week day ( β = −15.7 min ; P = 0.003 ) and weekend day ( β = −18.9 min ; P = 0.005 ) , in total screen-time on a weekday ( β = −25.9 min ; P = 0.03 ) and in the proportion of adolescents that did not meet the screen-time recommendation ( β = −4 percentage point ; P = 0.01 ) , compared to the control group . After the second stage ( data from n = 1078 adolescents ; control group n = 531 ) , the TV-time on a weekday ( β = 13.1 min ; P = 0.02 ) , and total screen-time on a weekday ( β = 21.4 min ; P = 0.03 ) increased more in adolescents from the intervention group . No adverse effects were reported . Discussion and Conclusion A multicomponent school-based intervention was only able to mitigate the increase in adolescents ’ television time and total screen-time after the first stage of the intervention or in other words , when the intervention included specific components or activities that focused on reducing screen-time . After the second stage of the intervention , which only included components and activities related to improve healthy diet and physical activity and not to decrease the  screen-time  , the adolescents increased their screen-time again . Our findings might imply that reducing screen-time is only possible when the intervention focuses specifically on reducing screen-time . Trial registration Clinical trials.gov identifier NCT01004367 OBJECTIVE To examine the prospect i ve association between objective ly measured time spent sedentary and insulin resistance and whether this association is independent of moderate- and vigorous-intensity physical activity ( MVPA ) and other relevant confounders . RESEARCH DESIGN AND METHODS This was a population -based study ( Medical Research Council Ely study ) in 376 middle-aged adults ( 166 men ; 210 women ) over 5.6 years of follow-up .  Physical activity and sedentary time were measured objective ly by individually calibrated minute-by-minute heart rate monitoring at both baseline and follow-up .  Sedentary time  was calculated as the heart rate observations ( in minutes ) below an individually predetermined threshold ( flex heart rate ) and expressed as a percentage of total monitored time during waking hours over 4 days . The percentage of time spent above 1.75 × resting heart rate represented MVPA . Fasting plasma insulin was used as a surrogate measure of insulin resistance . RESULTS Time spent sedentary  at baseline was significantly and positively associated with log fasting insulin at follow-up ( β = 0.003 , 95 % CI 0.0006–0.006 , P = 0.015 ) independent of baseline age , sex , fat mass , fasting insulin , smoking status , and follow-up time . After further adjustment for MVPA , this association was somewhat strengthened ( β = 0.004 , 95 % CI 0.0009–0.006 , P = 0.009 ) . CONCLUSIONS Time spent sedentary predicts higher levels of fasting insulin independent of the amount of time spent at moderate- and vigorous-intensity activity levels . This highlights the importance of reducing sedentary time in order to improve metabolic health , possibly in addition to the benefits associated with a physically active lifestyle BACKGROUND Previous research demonstrates that participation in light-intensity physical activity ( LIPA ) and moderate-to-vigorous physical activity ( MVPA ) are favorably associated with health-related quality of life ( HRQOL ) . Emerging work demonstrates that  sedentary behavior  ( SB ) is detrimentally associated with various cardiometabolic biomarkers , with few studies exploring the association of SB on HRQOL , and no studies examining this among congestive heart failure patients . Therefore , the purpose of this study was to examine the potential independent associations of SB on HRQOL among congestive heart failure patients . METHODS Data from the 2003 - 2006 National Health and Nutrition Examination Survey were used .  Physical activity was assessed over 7days during all waking hours using the ActiGraph 7164 accelerometer .  HRQOL was assessed using the Centers for Disease Control HRQOL index survey . RESULTS 190 participants self-reported a physician-diagnosis of congestive heart failure . After adjustments , SB behavior ( 1-min/day increase ) was associated with worse HRQOL ( β=0.004 ; 95 % CI : 0.0004 - 0.007 ; P=0.03 ) . When MVPA was added as a covariate to this model , SB remained significantly associated with worse HRQOL ( β=0.003 ; 95 % CI : 0.0001 - 0.007 ; P=0.04 ) . However , when adding LIPA to this model that also included MVPA as a covariate , SB was no longer associated with HRQOL ( β=0.0001 ; 95 % CI : -0.003 - 0.004 ; P=0.92 ) . CONCLUSIONS If confirmed by prospect ive/experimental work , this suggests that SB may not have detrimental HRQOL effects among congestive heart failure patients 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 Identifying ways to promote physical activity and decrease sedentary time during childhood is a key public health issue . Research on the putative influences on preschool children ’s  physical activity ( PA ) and  sedentary behavior  ( SB ) is limited and has yielded inconsistent results . Our aim was to identify correlates of PA and SB in preschool children . Methods Cross-sectional data were drawn from the Swiss Preschoolers ’ Health Study ( SPLASHY ) , a Swiss population -based cohort study . Of 476 two to six year old children , 394 ( 54 % boys ) had valid PA data assessed by accelerometry .  Information on exposure data was directly measured or extracted from parental question naires . Multilevel linear regression modeling was used to separately assess associations between 35 potential correlates and  total PA ( TPA ) , moderate-to-vigorous PA ( MVPA ) and SB . Results In total , 12 correlates from different domains were identified . TPA and MVPA were greater in boys than girls , increased with age and were positively associated with gross motor skills . Children from single parent families had a higher level of TPA and spent less time sedentary than those living with two parents . Time spent outdoors was positively associated with TPA and negatively with SB . The child ’s activity temperament was related all three outcomes , whereas parental sports club membership , living area per person and neighborhood safety were associated with SB only . Fixed and r and om factors in the final models accounted for 28 % , 32 % and 22 % of the total variance in TPA , MVPA and SB , respectively . Variance decomposition revealed that age , sex and activity temperament were the most influential correlates of both , TPA and MVPA , whereas the child ’s activity temperament , time outdoors and neighborhood safety were identified as the most important correlates of SB . Conclusions A multidimensional set of correlates of young children ’s  activity behavior has been identified . Personal factors had the greatest influence on PA , whereas environmental-level factors had the greatest influence on SB . Moreover , we identified a number of previously unreported , potentially modifiable correlates of young children ’s PA and SB . These factors could serve to define target groups or become valuable targets for change in future interventions .Trial registration Current Controlled Trials IS RCT N41045021 ( date of registration : 21.03.14 ) The risk of obesity during childhood can be significantly reduced through increased physical activity and decreased sedentary behavior . Recent technological advances have created opportunities for the real-time measurement of these behaviors . Mobile phones are ubiquitous and easy to use , and thus have the capacity to collect data from large numbers of people . The present study tested the feasibility , acceptability , and validity of an electronic ecological momentary assessment ( EMA ) protocol using electronic surveys administered on the display screen of mobile phones to assess children 's physical activity and sedentary behaviors .  A total of 121 children ( ages 9 - 13 , 51 % male , 38 % at risk for overweight/overweight ) participated in EMA monitoring from Friday afternoon to Monday evening during children 's nonschool time , with 3 - 7 surveys/day . Items assessed current activity ( e.g. , watching TV/movies , playing video games , active play/sports/exercising ) . Children simultaneously wore an Actigraph GT2 M accelerometer . EMA survey responses were time-matched to total step counts and minutes of moderate-to-vigorous physical activity ( MVPA ) occurring in the 30 min before each EMA survey prompt . No significant differences between answered and unanswered EMA surveys were found for total steps or MVPA . Step counts and the likelihood of 5 + min of MVPA were significantly higher during EMA-reported physical activity ( active play/sports/exercising ) vs. sedentary behaviors ( reading/computer/homework , watching TV/movies , playing video games , riding in a car ) ( P < 0.001 ) . Findings generally support the acceptability and validity of a 4-day EMA protocol using mobile phones to measure physical activity and sedentary behavior in children during leisure time
No significant associations between screen time with blood pressure and cholesterol were reported .
Sedentary behaviour appears to be associated with  adiposity in adolescents , irrespective of dietary intake .
Screen time , but not overall sedentary behaviour , is consistently related to cardiometabolic health in adolescents .
Because of the associations screen time has with dietary intake , diet may be an important factor in the screen time and health relationship ; however , evidence has not previously been synthesized .
Thus , the aim of this systematic review was to explore whether the associations between various sedentary behaviours and cardiometabolic risk markers are independent of dietary intake in adolescents .