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.

MATERIALS AND METHODS

Participants aged 17-19 years (n = 19) and ≥85th 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 completed testing on a traditional indirect calorimeter and a portable indirect calorimeter 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. 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 indicates that portable indirect calorimetry may be an acceptable option for assessing RMR in this population compared with the traditional indirect calorimeter or predictive equations.