The Association Between Physical Activity and Markers of Obesity in Children Living With Obesity.

Purpose: The purpose of this study is to describe the association between the volume and intensity of accelerometer-assessed physical activity (PA) and markers of obesity.

Method: Forty-seven children (20 girls) took part in this investigation. Children wore accelerometers on their nondominant wrists for 7 days. PA was expressed as average acceleration (AvAcc, proxy of PA volume), intensity gradient (IG, distribution of intensity across the 24-h profile), and the acceleration of the most active 5 to 120 minutes of the day (MX, where X = 5-120). Markers of obesity used were body mass index (BMI), BMI z score, obesity severity as the BMI percentage of the 95th percentile, waist-to-hip ratio, and body fat percentage.

Results: AvAcc and IG of the sample were 37.3 (11.2) and -2.19 (0.16), respectively. The standardized coefficients indicated that increases in 1 standard deviation of IG (0.2 for the present sample) were associated with a decrease of BMI (-2.3; 95% CI, -4.13 to -0.39 kg/m2), obesity severity as the BMI percentage of the 95th percentile (-9.9; 95% CI, -18.78 to -0.91), body fat percentage (-3.6; 95% CI, -6.68 to -0.57%), and waist-to-hip ratio (-0.02; 95% CI, -0.04 to -0.00) independent of AvAcc. No associations were found for AvAcc and obesity markers when controlling for IG.

Conclusion: Children with obesity perform little PA. The distribution of PA intensity may be important for improving BMI, obesity severity as the BMI percentage of the 95th percentile, body fat percentage, and waist-to-hip ratio.