Table 3.
Regression coefficients (95% confidence intervals) showing relations between children’s age and their fat mass and physical activity for the average child (minimally adjusted models)
| Boys | Girls | ||||||
|---|---|---|---|---|---|---|---|
| Fat mass (kg)* | Total physical activity (100 counts/min) | Moderate-vigorous physical activity (15 min/day)† | Fat mass (kg)* | Total physical activity (100 counts/min) | Moderate-vigorous physical activity (15 min/day)† | ||
| Intercept value at age 12 | 8.648 (8.437 to 8.865) | 6.544 (6.468 to 6.620) | 1.799 (1.607 to 1.991) | 11.143 (10.926 to 11.364) | 5.407 (5.348 to 5.466) | 1.108 (0.986 to 1.230) | |
| Linear or % change with age (per year)‡ | −7.4% (−9.3% to −5.5%) | −0.283 (−0.332 to −0.234) | 0.023 (−0.010 to 0.056) | 5.0% (3.7% to 6.3%) | −0.287 (−0.326 to −0.248) | 0.067 (0.043 to 0.091) | |
*Adjusted for height and height squared. These coefficients are taken from the bivariate model with fat mass and total activity as outcomes, but the corresponding coefficients from the model with fat mass and moderate-vigorous physical activity were similar.
†Adjusted for amount of time (minutes) that the accelerometer was worn.
‡For total activity and moderate-vigorous physical activity, the linear change with age is given. Log fat mass was used in the models, so the change in fat mass with age is best expressed as a percentage change.