title: A new hand-held indirect calorimeter to measure postprandial energy expenditure.
abstract: OBJECTIVE
  To verify the accuracy of a new hand-held metabolic rate measuring device (MedGem) in quantifying postprandial energy expenditure (PP EE). MedGem measurements were compared to measurements obtained with a conventional indirect calorimeter (Delta-Trac).
  
  
  METHODS
  The resting metabolic rate of 15 healthy subjects was measured for 20 minutes using Delta-Trac followed by a 10-minute measurement period using MedGem. EE was again measured for 7 hours after consumption of a 2510-kJ breakfast. Measurements were read from the Delta-Trac for the initial 50 minutes of each hour followed by a single reading from the MedGem after 5 to 10 minutes of measurement. Measured EE was calculated as the average of the total measurement period for Delta-Trac and for eight readings using MedGem; PP EE was calculated as the average of all measurements obtained after breakfast consumption.
  
  
  RESULTS
  There was no difference in resting metabolic rate between the two methods (6455.1 +/- 417.6 vs. 6468.5 +/- 337.2 kJ/d for Delta-Trac and MedGem, respectively). Measured EE and PP EE values with Delta-Trac (7019.1 +/- 400.8 and 7099.8 +/- 399.2 kJ/d, respectively) and MedGem (6775.6 +/- 372.0 and 6819.5 +/- 379.9 kJ/d, respectively) were not significantly different. There was no bias detected in any of the measurements made with MedGem compared with those of Delta-Trac.
  
  
  CONCLUSIONS
  The new hand-held EE measuring device can accurately track PP EE relative to a conventional indirect calorimetry system and, therefore, provides a new opportunity to assess PP EE in research settings and large-scale trials.
authors.affiliation: Obesity Research Center, Institute of Human Nutrition, Columbia University, New York, New York.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: St-Onge
authors.forename: Frederick
authors.initials: F
authors.lastname: Rubiano
authors.forename: Alfredo
authors.initials: A
authors.lastname: Jones
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
mesh_terms: D000328:Adult; D001481:Basal Metabolism; D001823:Body Composition; D002153:Calorimetry, Indirect / Q000295:instrumentation*; D004734:Energy Metabolism; D005502:Food; D006801:Humans; D012680:Sensitivity and Specificity