Conclusions Meta- analysis of data from prospect i ve cohort studies showed small , inconsistent and non-significant associations between sedentary behavior and body weight
Background The cumulative effect of too much sedentary behavior may contribute to  weight gain and obesity .
Objective The aim of this study was to conduct a systematic review and meta- analysis of prospect i ve cohorts and r and omized controlled studies to determine the association between sedentary  behavior  and body weight and obesity in adults .
Physical Activity, Television Viewing Time, and 12-Year Changes in Waist Circumference
ABSTRACT Purpose Both moderate-to-vigorous physical activity ( MVPA ) and sedentary behavior can be associated with adult adiposity . Much of the relevant evidence is from cross-sectional studies or from prospect i ve studies with relevant exposure measures at a single time point before weight gain or incident obesity . This study examined whether changes in MVPA and television ( TV ) viewing time are associated with subsequent changes in waist circumference , using data from three separate observation points in a large population -based prospect i ve study of Australian adults . Methods Data were obtained from the Australian Diabetes , Obesity , and Lifestyle study collected in 1999–2000 ( baseline ) , 2004–2005 ( wave 2 ) , and 2011–2012 ( wave 3 ) . The study sample consisted of adults age 25 to 74 yr at baseline who also attended site measurement at three time points ( n = 3261 ) . Multilevel linear regression analysis examined associations of initial 5-yr changes in MVPA and TV viewing time ( from baseline to wave 2 ) with 12-yr change in waist circumference ( from baseline to wave 3 ) , adjusting for well-known confounders . Results As categorical predictors , increases in MVPA significantly attenuated increases in waist circumference ( P for trend < 0.001 ) . TV viewing time change was not significantly associated with changes in waist circumference ( P for trend = 0.06 ) . Combined categories of  MVPA and TV viewing time changes were predictive of waist circumference increases ; compared with those who increased MVPA and reduced TV viewing time , those who reduced MVPA and increased TV viewing time had a 2-cm greater increase in waist circumference ( P = 0.001 ) . Conclusion Decreasing MVPA emerged as a significant predictor of increases in waist circumference . Increasing TV viewing time was also influential , but its impact was much weaker than MVPA
Conclusions Meta- analysis of data from prospect i ve cohort studies showed small , inconsistent and non-significant associations between sedentary behavior and body weight
Background The cumulative effect of too much sedentary behavior may contribute to  weight gain and obesity .
Objective The aim of this study was to conduct a systematic review and meta- analysis of prospect i ve cohorts and r and omized controlled studies to determine the association between sedentary  behavior  and body weight and obesity in adults .