Time to achieve steady state for an accurate assessment of resting energy expenditure in adolescents with healthy weight and obesity: A cross-sectional study

Comparison of energy expenditure measurements by a new basic respiratory room vs. classical ventilated hood

BACKGROUND

Nutritional support is often based on predicted resting energy expenditure (REE). In patients, predictions seem invalid. Indirect calorimetry is the gold standard for measuring EE. For assessments over longer periods (up to days), room calorimeters are used. Their design makes their use cumbersome, and warrants improvements to increase utility. Current study aims to compare data on momentary EE, obtained by a basic respiration room vs. classical ventilated hood. The objective is to compare results of the basic room and to determine its 1)reliability for measuring EE and 2)sensitivity for minute changes in activity.

METHODS

Two protocols (P1; P2)(n = 62; 25 men/37 women) were applied. When measured by hood, participants in both protocols were in complete rest (supine position). When assessed by room, participants in P1 were instructed to stay half-seated while performing light desk work; in P2 participants were in complete rest mimicking hood conditions. The Omnical calorimeter operated both modalities. Following data were collected/calculated: Oxygen uptake ([Formula: see text] O2(ml/min)), carbon dioxide production ([Formula: see text] CO2ml/min), 24h_EE (kcal/min), and respiratory exchange ratio (RER). Statistical analyses were done between modalities and between protocols. The agreement between 24h_EE, [Formula: see text] O2 and [Formula: see text] CO2 obtained by both modalities was investigated by linear regression. Reliability analysis on 24h_EE determined ICC.

RESULTS

No significant differences were found for 24h_EE and [Formula: see text] O2. [Formula: see text] CO2 significantly differed in P1 + P2, and P2 (hood > room). RER was significantly different (hood > room) for P1 + P2 and both protocols individually. Reliability of 24h_EE between modalities was high. Modality-specific results were not different between protocols.

DISCUSSION/CONCLUSION

The room is valid for assessing momentary EE. Minute changes in activity lead to a non-significant increase in EE and significant increase in RER. The significant difference in [Formula: see text] CO2 for hood might be related to perceived comfort. More research is necessary on determinants of RER, type (intensity) of activity, and restlessness. The design of the room facilitates metabolic measurements in research, with promising results for future clinical use.

Effect of a Supervised Exercise Program on Overweight and Obese Adolescents in the School Environment: A Pretest-Posttest Design

This study is taken up to evaluate the effect of an exercise program on adolescents' obesity and overweight profile. For this purpose, a 1-group pretest-posttest study was conducted with 72 adolescents who underwent a physical activity program supervised by one health professional 5 times a week; the sessions were distributed over 12 weeks and lasted from 50 to 60 minutes. The primary outcomes were anthropometric measurements, whereas the secondary outcomes were lipid profile, blood glucose, and blood pressure. Outcomes were assessed before the intervention and 1 day after the program ended; significance was established at P < .05. As a result, a significant improvement was verified in all the primary outcomes (P< .001) and in most secondary outcomes (capillary blood glucose, P = .0001; triglycerides, P = .0001; and systolic blood pressure, P = .005). In conclusion, the supervised exercise program significantly reduced anthropometric measurements and blood glucose, triglycerides, and systolic blood pressure levels.