Only English language publications which included children and adolescents aged 4–18 years old were included. How active are obese children? Are they less active than their non-obese counterparts? It would seem that regardless of the measurement device, (accelerometry, heart rate measurement, or doubly-labeled water), the obese children generally exhibit lower levels of activity. For example, Maffeis and colleagues14 used heart rate monitoring to estimate PA in a small group of 8–10-year-old obese (body GSK1120212 mouse mass index (BMI) >97th percentile) and non-obese children. Non-obese children spent about 100 min a day more being physically active (all activity above sedentary behavior) than the obese children. Moderate

Selleck CH5424802 to vigorous PA was similar in the two groups, so the difference in total daily activity was accounted for by light intensity activity. The authors also found that the obese children spent more time (approximately 100 min a day) engaged in sedentary pursuits compared to the non-obese children. These findings are similar to Yu et al.15 who also used heart rate derived estimates of energy expenditure to compare total activity (activity above sedentary

behavior) and sedentary behavior between 18 obese (BMI ≥95th percentile) and 18 non-obese 6–18-year-olds. The obese youngsters in Yu et al.’s15 study spent 30% less of the monitored time engaged in physically active pursuits (no data are provided for the breakdown of light, moderate or vigorous activity), but 51% more time engaged in sedentary activities during the waking hours. Accelerometry studies also found lower PA levels in obese youngsters. In a group of 53 obese (BMI ≥98th percentile) and 53 non-obese boys and girls (mean age 8.6 years), Hughes and colleagues16

found total activity time (mean accelerometer counts/min) others was lower in the obese (648 counts/min) compared to non-obese children (729 counts/min). Interestingly there was no difference in time spent being sedentary between the two groups of children in this study. When the proportion of the time spent engaged in activities of moderate to vigorous intensity was compared this was marginally less (2.4%) in the obese (average of about 16 min a day) compared to the non-obese (average of about 23 min a day). Similarly, Page et al.17 found that time spent being moderately to vigorously active was slightly less in 14 obese (BMI >99th percentile; average of about 10 min a day) compared with 54 non-obese (average of about 13 min a day) 10-year-olds. Although total activity and PA are generally less in the obese children and adolescent compared to the non-obese, total activity energy expenditure is not always reduced. Ekelund et al.18 assessed total activity energy expenditure and PA using a combined doubly-labeled water and accelerometer approach in 18 obese (BMI >30 kg/m2) and 18 non-obese adolescents.