title: Validation of a field technique for the measurement of energy expenditure: factorial method versus continuous respirometry.
abstract: The field technique for measuring daily energy expenditure, using activity diary plus short-term indirect calorimetry, was validated with a room respirometer. Eleven male and 14 female subjects spent 24-h periods in the respirometer and kept an activity diary to the nearest minute. Subsequently, the energy cost of the recorded activities was measured in duplicate, and 24-h expenditure was calculated. Over the 42 24-h measurements the mean value by the factorial field method was within 1% of that from continuous indirect calorimetry. However, the error in individual daily expenditure ranged from -17% to +25%. Correction of the error involved in using calculated BMR for the cost of sleeping resulted in a 5% mean underestimation of the daily value. The factorial method is, therefore, too inaccurate for the estimation of individual daily expenditures but provides a close estimate of the true energy expenditure for population groups.
mesh_terms: D000328:Adult; D002151:Calorimetry / Q000295:instrumentation*; D002153:Calorimetry, Indirect / Q000295:instrumentation*; D004734:Energy Metabolism; D004780:Environment, Controlled; D005260:Female; D006801:Humans; D008297:Male; D005082:Physical Exertion; D012119:Respiration; D012890:Sleep / Q000502:physiology