Abstract
Practical methods of assessing resting energy expenditure (REE) could be useful in large populations of overweight and obese individuals during phases of weight loss and weight-loss maintenance to address weight regain. We compared predicted and measured REE using the MedGem handheld device and a traditional, indirect calorimeter in middle-aged men and women who were overweight and obese (body mass index ≥ 25.0 and <40.0). Each subject (n=88) completed traditional, indirect calorimetry and handheld calorimetry in random order. A subset of participants (n=10) completed each of these assessments at three different time points to examine their test-retest reliability. We found that MedGem estimates of REE were significantly greater than estimates with the traditional, indirect calorimeter and the predicted REE using the Harris-Benedict equation (P<0.01). Intra-class correlations were .70 (P=0.15) for repeated recordings with the MedGem and .84 (P=0.65) for traditional indirect calorimetry. The MedGem can overestimate REE in middle-aged overweight/obese individuals and has moderate test-retest reliability. Indirect calorimetry is the preferred measurement of REE in this population.