Hand-Held Indirect Calorimeter Offers Advantages Compared with Prediction Equations, in a Group of Overweight Women, to Determine Resting Energy Expenditures and Estimated Total Energy Expenditures during Research Screening

Abstract

ObjectiveTo compare standardized prediction equations to a hand-held indirect calorimeter in estimating resting energy and total energy requirements in overweight women. DesignResting energy expenditure (REE) was measured by hand-held indirect calorimeter and calculated by prediction equations Harris-Benedict, Mifflin-St Jeor, World Health Organization/Food and Agriculture Organization/United Nations University (WHO), and Dietary Reference Intakes (DRI). Physical activity level, assessed by questionnaire, was used to estimate total energy expenditure (TEE). SubjectsSubjects (n=39) were female nonsmokers older than 25 years of age with body mass index more than 25. Statistical analysesRepeated measures analysis of variance, Bland-Altman plot, and fitted regression line of difference. A difference within ±10% of two methods indicated agreement. ResultsSignificant proportional bias was present between hand-held indirect calorimeter and prediction equations for REE and TEE (P<0.01); prediction equations overestimated at lower values and underestimated at higher values. Mean differences (±standard error) for REE and TEE between hand-held indirect calorimeter and Harris-Benedict were −5.98±46.7 kcal/day (P=0.90) and 21.40±75.7 kcal/day (P=0.78); between hand-held indirect calorimeter and Mifflin-St Jeor were 69.93±46.7 kcal/day (P=0.14) and 116.44±75.9 kcal/day (P=0.13); between hand-held indirect calorimeter and WHO were −22.03±48.4 kcal/day (P=0.65) and −15.8±77.9 kcal/day (P=0.84); and between hand-held indirect calorimeter and DRI were 39.65±47.4 kcal/day (P=0.41) and 56.36±85.5 kcal/day (P=0.51). Less than 50% of predictive equation values were within ±10% of hand-held indirect calorimeter values, indicating poor agreement. ConclusionsA significant discrepancy between predicted and measured energy expenditure was observed. Further evaluation of hand-held indirect calorimeter research screening is needed.