Impaired physical function associated with childhood obesity: how should we intervene?

Background: This study examined relationships between adiposity, physical functioning, and physical activity.

Methods: Obese (N = 107) and healthy-weight (N = 132) children aged 10–13 years underwent assessments of percent body fat (�, dual energy X-ray absorptiometry); knee extensor strength (KE, isokinetic dynamometry); cardiorespiratory fitness (CRF, peak oxygen uptake by cycle ergometry); physical health-related quality of life (HRQOL); and worst pain intensity and walking capacity [six-minute walk (6MWT)]. Structural equation modelling was used to assess relationships between variables.

Results: Moderate relationships were observed between � and (1) 6MWT, (2) KE strength corrected for mass, and (3) CRF relative to mass (r −0.36 to −0.69, p ≤ 0.007). Weak relationships were found between � and physical HRQOL (r −0.27, p = 0.008); CRF relative to mass and physical HRQOL (r −0.24, p = 0.003); physical activity and 6MWT (r 0.17, p = 0.004). Squared multiple correlations showed that 29.6% variance in physical HRQOL was explained by �, pain, and CRF relative to mass; while 28.0% variance in 6MWT was explained by � and physical activity.

Conclusions: It appears that children with a higher body fat percentage have poorer KE strength, CRF, and overall physical functioning. Reducing percent fat appears to be the best target to improve functioning. However, a combined approach to intervention, targeting reductions in body fat percentage, reductions in pain, and improvements in physical activity and CRF may assist physical functioning.