Search

Background and Aims: The accuracy of some portable indirect calorimeters in estimating resting energy expenditure (REE) - and hence energy recommendations - among pre-bariatric patients is unknown. Our objective was to assess the accuracy of the MedGem® among individuals with class II or III obesity awaiting bariatric surgery., Methods: Male and female adults who were awaiting bariatric surgery were recruited to this cross-sectional study. MedGem-derived oxygen consumption (O 2 ) and REE were compared to O 2 and REE from a metabolic cart. REE was also calculated using several common equations to assess the clinical utility of this portable tool. Body composition was assessed by dual energy X-Ray absorptiometry. Paired t-test and Bland-Altman analysis (expressed as bias [average difference] and limits of agreement [bias ± 2 standard deviations]) evaluated O 2 and REE accuracy., Results: Twenty-six individuals were included (34 ± 9 years old; n = 20, 76.9% female), with the majority (n = 15, 57.7%) having class II obesity. Neither O 2 (MedGem: 283 ± 63 vs. metabolic cart: 293 ± 64 ml/min, p = 0.114) nor REE (MedGem: 1963 ± 437 vs. metabolic cart: 2047 ± 440 kcal/day, p = 0.057) were different between devices. Body composition did not relate to bias. The MedGem had wide limits of agreement for REE (-504 to 336 kcal/day), which was similar to predictive equations., Conclusions: Although REE from the MedGem was not different than REE from the metabolic cart, individual-level accuracy was poor and similar to predictive equations in patients with class II or III obesity. Nonetheless, efficacy of repeated assessments during weight loss warrant future investigation., Competing Interests: Declaration of competing interest There are no conflict of interests with any of the companies/manufacturers of devices/techniques used in this study. This research study included the opinions of the authors; no official endorsement by the Canadian Foundation for Dietetic Research (CFDR) was intended or inferred., (Copyright © 2020 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

Background/objectives: Resting energy expenditure (REE) is the largest component of total energy expenditure. As such, inaccurate estimation or measurement of REE may impact the development of individualized energy intake recommendations. The objective of this observational study was to assess the accuracy and reliability of REE measured with a portable indirect calorimeter with ventilated hood - Fitmate GS - compared to REE from whole-body indirect calorimetry (WBC)., Methods: REE was assessed using the Fitmate GS and compared to REE from WBC in male and female adults. Fitmate GS tests were repeated on a separate visit. Body fat percent, fat mass, and fat-free mass were assessed using dual X-ray absorptiometry in a subset of individuals with body mass index (BMI) ≥35 kg/m 2 . Paired t-tests and Bland-Altman analyses were used to describe REE accuracy; intra-class correlation coefficient (ICC) examined test-retest reliability of repeated Fitmate GS assessments., Results: Fitmate GS and WBC REE was assessed in 77 adults (age 32 ± 8 years; 63.6% females; 53.2% with BMI ≥ 30 kg/m 2 ). The Fitmate GS underestimated REE (1680 ± 420 vs. 1916 ± 461 kcal/day, p < 0.001) and wide limits of agreement were observed (95% confidence intervals [CI]: -727, 246 kcal/day). Bias was similar across sex and BMI categories and did not correlate to any body composition parameter. Fitmate GS ICC was 0.80 (95% CI: 0.70-0.87), indicating 'good' reliability with repeated testing after median follow-up of 4 days (interquartile range 2-7 days)., Conclusion: The Fitmate GS did not accurately quantify REE but produced reliable REE measurements., Competing Interests: Conflict of interest disclosure COSMED (Chicago, IL) provided the portable indirect calorimeter (Fitmate GS) used in this study. COSMED did not provide financial support nor played a role in data analysis or drafting of the manuscript. This research study included the opinions of the authors; no official endorsement by the Canadian Foundation for Dietetic Research (CFDR) was intended or inferred., (Copyright © 2020 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)