Objective: To compare energy expenditure (EE) measured by doubly labeled water (DLW) with other measures, both physical and based on subjective questionnaires.
Design: A comparison of methods in a stratified sample of adult volunteers.
Setting: The feeding behaviour suite (FBS) at the Rowett Research Institute, Aberdeen.
Subjects: A total of 59 subjects, stratified for age, sex and body mass index (BMI).
Interventions: EE was assessed by DLW (validated using measurements of energy balance), heart rate monitor (HRM), activity monitor (Caltrac), 24-h physical activity diary (PAD) and 7-day physical activity recall. Energy intake was assessed using covert (investigator-weighed) food intake (EI). Data were collected over a 12-day period of residence in the Rowett's FBS.
Results: No methods correlated highly with physical activity assessed by DLW. Physical methods correlated more closely than did subjective recording. All methods (except EI) significantly underestimated EE, estimated by DLW. There were no significant differences in association between methods and sex, age, BMI or fat-free mass.
Conclusion: EE is difficult to measure precisely or accurately with current approaches but physical methods are slightly better than subjective accounts.