Multilevel regression model for TB BMD, FN BMD and LS BMD values when controlling for biological age, height, lean mass and testing for SED and VPA.

<p>SE is standard error. Biological age - years from age at peak height velocity (APHV). SED - sedentary time. VPA - vigorous physical activity. Group effect is four different groups according to baseline BMI.</p><p>Multilevel regression model for TB BMD, FN BMD and LS BMD values when controlling for biological age, height, lean mass and testing for SED and VPA.</p

Mean (± SD) characteristics of the subjects at baseline measurement.

a<p>Significantly different from underweight boys;</p>b<p>significantly different from normal weight boys;</p>c<p>significantly different from overweight boys;</p>d<p>significantly different from obese boys (P<0.05);</p><p>Biological age is years from APHV (age at peak height velocity); BMI, body mass index; TB BMD, total body bone mineral density; FN BMD, femoral neck bone mineral density; LS BMD, lumbar spine bone mineral density; SED, sedentary time; MVPA, moderate and vigorous physical activity.</p><p>Mean (± SD) characteristics of the subjects at baseline measurement.</p

The change of PA levels during the study period in four different groups of participants.

a<p>Significantly different from underweight boys;</p>b<p>significantly different from normal weight boys; (P<0.05);</p>1<p>significantly different from baseline PA level;</p>2<p>significantly different from PA level after 12 month;</p><p>SED, sedentary time; LPA, light physical activity; MPA, moderate physical activity; VPA, vigorous physical activity; MVPA, moderate to vigorous physical activity.</p><p>The change of PA levels during the study period in four different groups of participants.</p

Multilevel regression model for TB BMD, FN BMD and LS BMD controlling for biological age, height, lean body mass and testing for SED and MVPA.

<p>SE is standard error. Biological age - years from age at peak height velocity (APHV). SED - sedentary time. MVPA - moderate to vigorous physical activity. Group effect is four different groups according to baseline BMI.</p><p>Multilevel regression model for TB BMD, FN BMD and LS BMD controlling for biological age, height, lean body mass and testing for SED and MVPA.</p

TB BMD changes during pubertal growth spurt.

<p>Comparing four different groups – underweight, normal weight, overweight and obese pubertal boys. APHV - age of peak height velocity.</p