Comparison of energy expenditure estimates from doubly labeled water, a physical activity questionnaire, and physical activity records

Abstract

Background: Various methods are used by epidemiologists to estimate the energy cost of physical activity; these include physical activity records and recalls. However, there is limited validation of these methods against the doubly labeled water technique for determining energy expenditure (EE). Objective: We compared EE as estimated by indirect methods (physical activity records and recall questionnaires) used in epidemiologic studies with EE obtained from doubly labeled water (EE_DLW) in free-living men. Design: We determined EE_DLW, energy intake at weight maintenance, and EE from 7-d physical activity records (EE_Record) and a 7-d physical activity recall questionnaire (EE_Recall) in 24 men aged 41 ± 2.0 y (x̄ ± SEM) with a body mass index (in kg/m²) of 25.1 ± 0.5. Results: There was excellent agreement between EE_DLW (13.27 ± 0.35 MJ/d) and energy intake (13.19 ± 0.36 MJ/d), with a difference of 0.5 ± 1.0% (x̄ ± SE). The indirect measures of physical activity and EE were 14.17 ± 0.37 MJ/d for EE_Record (difference from EE_DLW: 7.9 ± 3.2%) and 17.40 ± 1.45 MJ/d for EE_Recall (difference from EE_DLW: 30.6 ± 9.9%). Conclusions: Seven-day physical activity records provide an acceptable estimate of EE in free-living adults compared with EE_DLW, but 7-d physical activity recalls have limited application to estimate daily EE. For optimal validity, the 7-d physical activity records require good subject compliance and the provision of careful instructions for their use.