Assessing Resting Metabolic Rate in Overweight and Obese Adolescents With a Portable Indirect Calorimeter:

A Pilot Study for Validation and Reliability.

Background:

Indirect Calorimetry measured via the traditional indirect calorimeter is considered the “gold standard” for determining resting metabolic rate (RMR). Portable devices for assessing RMR are a less expensive option for measuring RMR in the clinical setting. This pilot study tested the reliability and validity of a portable device for measuring RMR, specifically in overweight and obese adolescents

Methods

Participants ages 17-19 years (n=19) and ˃85^th percentile on the Centers for Disease Control and Prevention body mass index growth curves for age and sex were recruited from a university campus. Participants competed testing on a traditional indirect calorimeter (CosMed Quark) and a portable indirect calorimeter (KORR ReeVue) in a randomized order on 2 separate testing days.

Results

A paired samples t test comparing the means of the portable device and the traditional indirect calorimeter found no significant difference (P=.22). The test-retest intraclass correlation coefficient for assessing RMR was 0.91, indicating reliability of the portable indirect calorimeter (KORR ReeVue). Compared with measured RMR, the Mifflin-St Jeor equation demonstrated 37% accuracy, and the Molnar equation demonstrated 57% accuracy.

Conclusion:

This pilot study found portable indirect calorimetry to be reliable and valid for assessing RMR in an overweight and obese adolescent population. In addition, this study indicated that portable indirect calorimetry may be an acceptable option for assessing RMR in this population compared with the traditional indirect calorimeter or predictive equations.

Authors

Sarah T Henes, PhD, RD, LD.  Dept of Nutrition, Georgia State University, Atlanta Georgia
Abby Johnson, MS, RD.  Dept of Nutrition, Georgia State University, Atlanta Georgia
Marti Toner, MS.  Dept of Nutrition, Georgia State University, Atlanta Georgia
Kamille Mamaril.  School of Nursing, Georgia State University, Atlanta Georgia
Maya Kelkar.  School of Nursing, Georgia State University, Atlanta Georgia
Yuanhui Xiao, PhD.  Department of Mathematics and Statistics, Mississippi State University
Gordon L Warren, PhD.  Department of Physical Therapy, Georgia State University.