Estimation of Free‐Living Energy Expenditure Using a Novel Activity Monitor Designed to Minimize Obtrusiveness

Abstract

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/m2). The habitual physical activity was monitored for 14 days using a DirectLife triaxial accelerometer for movement registration (TracmorD) (Philips New Wellness Solutions, Lifestyle Incubator, the Netherlands). TracmorD 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‐r2 = 0.55, P < 0.001), and Cnts/d (partial r2 = 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‐r2 = 0.31, P < 0.001) and Cnts/d (partial‐r2 = 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 TracmorD 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.

Design and baseline characteristics of the Food4Me study: a web-based randomised controlled trial of personalised nutrition in seven European countries

“…PA patterns were determined using a PA monitor-the DirectLife triaxial accelerometer for movement registration (TracmorD) (Philips Consumer Lifestyle, the Netherlands; Bonomi et al 2010;Plasqui et al 2005;Plasqui and Westerterp 2007)-and a self-reported Baecke PA questionnaire (Baecke et al 1982) which was completed online. The accelerometer-based monitor (Philips DirectLife Activity Monitor, the Netherlands) was posted to each participant.…”

Advances in physical activity monitoring and lifestyle interventions in obesity: a review

“…Tracmor D (Philips New Wellness Solutions, Lifestyle Incubator) provides visual feedback to the activity monitor user in terms of percentage of activity performed as compared with a specific target established in the intervention program. 66 This would increase the ability of the user to act in response to the indication of an inadequate activity level.…”

“…64,65 A more recent version of this accelerometer, the DirectLife tri-axial accelerometer for movement registration (Tracmor D; Philips New Wellness Solutions, Lifestyle Incubator), showed similar prediction accuracy of energy expenditure in free-living conditions. 66 The activity counts measured with Tracmor D (Philips New Wellness Solutions, Lifestyle Incubator) added 23% to the explained variation in AEE after adjustment for subject characteristics, and the prediction model had a standard error of estimation of 0.9 MJ day À1 . Although significant estimations of AEE have been shown with an accelerometer, there are pragmatic limitations to the use of activity counts to estimate energy expenditure.…”

Evaluation of Actiheart and a 7 d activity diary for estimating free-living total and activity energy expenditure using criterion methods in 1·5- and 3-year-old children

“…For instance, a triaxial accelerometer, Tracmor, has yielded promising results in adults (9) and in a group of 3-to 4-year-old children (6) . However, this device is currently not commercially available for use in young children.…”