title: Comparison of doubly labeled water with respirometry at low- and high-activity levels.
abstract: In previous studies the doubly labeled water method for measuring energy expenditure in free-living humans has been validated against respirometry under sedentary conditions. In the present investigation, energy expenditure is measured simultaneously with doubly labeled water and respirometry at low- and high-activity levels. Over 6 days, five subjects were measured doing mainly sedentary activities like desk work; their average daily metabolic rate was 1.40 +/- 0.09 (SD) times sleeping metabolic rate. Four subjects were measured twice over 3.5 days, including 2 days with heavy bicycle ergometer work, resulting in an average daily metabolic rate of 2.61 +/- 0.25 (SD) times sleeping metabolic rate. At the low-activity level, energy expenditures from the doubly labeled water method were on the average 1.4 +/- 3.9% (SD) larger than those from respirometry. At the high-activity level, the doubly labeled water method yielded values that were 1.0 +/- 7.0% (SD) lower than those from respirometry. Results demonstrate the utility of the doubly labeled water method for the determination of energy expenditure in the range of activity levels in daily life.
mesh_terms: D000328:Adult; D001481:Basal Metabolism; D002245:Carbon Dioxide / Q000032:analysis; D003903:Deuterium; D004734:Energy Metabolism; D005080:Exercise Test; D005260:Female; D006801:Humans; D007553:Isotope Labeling / Q000379:methods*; D008297:Male; D010104:Oxygen Radioisotopes; D012119:Respiration
chemical_list: D010104:Oxygen Radioisotopes; D002245:Carbon Dioxide; D003903:Deuterium