Purpose: To examine the ability of the SenseWear Pro2 Armband (SWA) to accurately assess energy expenditure in free-living overweight or obese children during a two-week period, by comparison with energy expenditure measured using the doubly labeled water (DLW) method. A second aim was to examine which software version, Innerview Professional 5.1 or Sensewear Professional 6.0, are the most appropriate for use together with SWA in overweight and obese children.

Method: A random sample of 22 healthy, overweight or obese children (11 girls and 11 boys) aged 8-11 years was recruited from an ongoing intervention study. Energy expenditure in free-living conditions was simultaneously assessed with the SWA and DLW methods during a 14-day period. All data from the SWA were analyzed using InnerView Professional software versions 5.1 (SWA 5.1) and 6.1 (SWA 6.1).

Results: An accurate estimation in energy expenditure was obtained when SWA 5.1 was used, showing a non-statistically significant difference corresponding to 17 (1200) kJ[middle dot]d-1 compared with the energy expenditure measured using the DLW method. However, when SWA 6.1 was used a statistically significant (18%) underestimation of energy expenditure was obtained, corresponding to 1962 (1034) kJ[middle dot]d-1 compared with the DLW method.

Conclusion: The SWA together with software version 5.1, but not 6.1, is a valid method for accurately measuring energy expenditure at group level of free-living overweight and obese children.