Daily physical activity related to body fat in children aged 8-11 years

Objective

To evaluate the association between objectively measured daily physical activity and body fat.

Study design

Cross-sectional, observational, study of 248 children aged 7.9 to 11.1 years. Abdominal fat mass and total body fat mass were measured by dual-energy X-ray absorptiometry. Daily physical activity was assessed by accelerometers for 4 days.

Results

Total body fat expressed as a percentage of body mass was inversely related to minutes of vigorous physical activity per day, for all children r = −0.38 (P < .05). Children, both boys and girls, in the highest quartile of body fat performed on average 12 minutes less vigorous activity per day compared with their counterparts in the lowest quartile. Multiple regression analysis revealed that independent factors for body fat were number of minutes of vigorous activity per day and sex.

Conclusion

Low physical activity can be a contributing factor in childhood obesity. Only longitudinal studies, however, can give more definitive information about the relation between daily physical activity and obesity.

Abbreviations:  AEE, Activity-related energy expenditure , AFM, Abdominal fat mass , BF%, Percentage of total body mass , BMI, Body mass index , DLW, Doubly labeled water , DXA, Dual-energy X-ray absorptiometry , MET, Metabolic equivalent , SD, Standard deviation , TBF, Total body fat mass