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Estimation of Free‐Living Energy Expenditure Using a Novel Activity Monitor Designed to Minimize Obtrusiveness
Author(s) -
Bonomi Alberto G.,
Plasqui Guy,
Goris Annelies H.C.,
Westerterp Klass R.
Publication year - 2010
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1038/oby.2010.34
Subject(s) - energy expenditure , physical activity , doubly labeled water , zoology , medicine , linear regression , energy metabolism , partial correlation , metabolic equivalent , mathematics , statistics , demography , physical therapy , biology , correlation , geometry , sociology
The aim of this study was to investigate the ability of a novel activity monitor designed to be minimally obtrusive in predicting free‐living energy expenditure. Subjects were 18 men and 12 women (age: 41 ± 11 years, BMI: 24.4 ± 3 kg/m 2 ). The habitual physical activity was monitored for 14 days using a DirectLife triaxial accelerometer for movement registration (Tracmor D ) (Philips New Wellness Solutions, Lifestyle Incubator, the Netherlands). Tracmor D output was expressed as activity counts per day (Cnts/d). Simultaneously, total energy expenditure (TEE) was measured in free living conditions using doubly labeled water (DLW). Activity energy expenditure (AEE) and the physical activity level (PAL) were determined from TEE and sleeping metabolic rate (SMR). A multiple‐linear regression model predicted 76% of the variance in TEE, using as independent variables SMR (partial‐ r 2 = 0.55, P < 0.001), and Cnts/d (partial r 2 = 0.21, P < 0.001). The s.e. of TEE estimates was 0.9 MJ/day or 7.4% of the average TEE. A model based on body mass (partial‐ r 2 = 0.31, P < 0.001) and Cnts/d (partial‐ r 2 = 0.23, P < 0.001) predicted 54% of the variance in TEE. Cnts/d were significantly and positively associated with AEE ( r = 0.54, P < 0.01), PAL ( r = 0.68, P < 0.001), and AEE corrected by body mass ( r = 0.71, P < 0.001). This study showed that the Tracmor D is a highly accurate instrument for predicting free‐living energy expenditure. The miniaturized design did not harm the ability of the instrument in measuring physical activity and in determining outcome parameters of physical activity such as TEE, AEE, and PAL.