Healthy Non-Obese Adults (2010-2012)
Livingston EH, Kohlstadt I. Simplified resting metabolic rate - predicting formulas for normal-sized and obese individuals. Obes Res. 2005; 13 (7): 1,255-1,262.PubMed ID: 16076996
The study tested whether resting metabolic rate (RMR) can be predicted from an allometric formula with weight alone as an independent variable.
- Complete medical evaluation showing that patients were free of significant disease that potentially could alter RMR measurements
- Metabolic panel showing that the patients did not have thyroid conditions
- Chest X-ray and medical exam verifying that respiratory illness was not present.
Patients taking medications were not excluded, although if a patient was on a medication known to alter RMR, the test was not performed.
- Recruitment: Patients were recruited from a university-based weight-management program involving a physician-supervised very-low-calorie diet
- Design: Diagnostic, validity or reliability study
- Blinding used: Implied with measurements.
- The weight-RMR relationship was assessed by non-linear regression with the allometric power formula: RMR=a x weightb
- Non-linear regression was performed with the SigmaPlot Graphing package (SPSS, Chicago, IL)
- For assessment of the effect age had on RMR prediction, a second equation was solved: RMR=a x weightb + (C x age).
- RMR prediction with the Harris-Benedict type of formula follows the general form of: RMR=constant + A1 Weight + A2Height + A3Age, where constant A1, A2 and A3 were solved by multiple regression using the SAS program
- Significance of the fitted coefficients was assumed when P<0.05
- The proportion of RMR variance accounted for each coefficient by semi-partial correlation analysis using type II sum of squares.
Timing of Measurements
All measurements made at the same time.
- Resting metabolic rate was measured as part of a comprehensive medical evaluation for patients participating in a university-based weight-management program involving a physician-supervised very-low-calorie diet. RMR was measured by indirect calorimetry using a Beckman Metabolic Cart. One of two certified exercise physiologists in a standardized room measured subjects.
- The test was conducted twice with the higher of the two RMRs selected for the analysis
- RMR was predicted by the James, allometric and Harris-Benedict formulas.
- Initial N: 356 measured women and 299 measured men
- Attrition (final N): 356 measured women and 299 measured men
- Age: Women mean age, 39±13 years; men mean age, 36±15 years
- Ethnicity: Not described
- Other relevant demographics: Not reported
- Anthropometrics: Mean weight for women, 90±37kg; mean weight for men, 96±45kg
- Location: Not reported, data secured from Harris-Benedict and Owen databases.
- Power law modeling of the RMR-body weight relationship yielded the following RMR-predicting equations:
- RMR women: 248 x weight0.4536 - (5.09 x age)
- RMR men: 293 x weight0.4330 - (5.92 x age).
- Partial correlation analysis revealed that age significantly contributed to RMR variance and was necessary to include in RMR prediction formulas
- The James, allometric and Harris-Benedict formulas all yielded reasonable RMR predictions for normal-sized and obese subjects.
- A simple power formula relating RMR to body weight can be a reasonable RMR estimator for normal-sized and obese individuals, but still requires an age term and separate formulas for men and women for the best possible RMR estimates
- The apparent performance of RMR-predicting formulas is highly dependent on the methodology employed to compare the various formulas.
|Other:||Hudsen-Penn Endowment Fund|
Questionable validity of the Beckman Metabolic Cart.
Quality Criteria Checklist: Primary Research
|1.||Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)||N/A|
|2.||Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?||Yes|
|3.||Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?||Yes|
|4.||Is the intervention or procedure feasible? (NA for some epidemiological studies)||N/A|
|1.||Was the research question clearly stated?||Yes|
|1.1.||Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?||Yes|
|1.2.||Was (were) the outcome(s) [dependent variable(s)] clearly indicated?||Yes|
|1.3.||Were the target population and setting specified?||Yes|
|2.||Was the selection of study subjects/patients free from bias?||Yes|
|2.1.||Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?||Yes|
|2.2.||Were criteria applied equally to all study groups?||Yes|
|2.3.||Were health, demographics, and other characteristics of subjects described?||Yes|
|2.4.||Were the subjects/patients a representative sample of the relevant population?||Yes|
|3.||Were study groups comparable?||Yes|
|3.1.||Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)||Yes|
|3.2.||Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?||Yes|
|3.3.||Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)||Yes|
|3.4.||If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?||N/A|
|3.5.||If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)||N/A|
|3.6.||If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?||No|
|4.||Was method of handling withdrawals described?||Yes|
|4.1.||Were follow-up methods described and the same for all groups?||Yes|
|4.2.||Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)||Yes|
|4.3.||Were all enrolled subjects/patients (in the original sample) accounted for?||Yes|
|4.4.||Were reasons for withdrawals similar across groups?||Yes|
|4.5.||If diagnostic test, was decision to perform reference test not dependent on results of test under study?||Yes|
|5.||Was blinding used to prevent introduction of bias?||Yes|
|5.1.||In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?||N/A|
|5.2.||Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)||Yes|
|5.3.||In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?||N/A|
|5.4.||In case control study, was case definition explicit and case ascertainment not influenced by exposure status?||N/A|
|5.5.||In diagnostic study, were test results blinded to patient history and other test results?||Yes|
|6.||Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?||Yes|
|6.1.||In RCT or other intervention trial, were protocols described for all regimens studied?||N/A|
|6.2.||In observational study, were interventions, study settings, and clinicians/provider described?||N/A|
|6.3.||Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?||Yes|
|6.4.||Was the amount of exposure and, if relevant, subject/patient compliance measured?||Yes|
|6.5.||Were co-interventions (e.g., ancillary treatments, other therapies) described?||Yes|
|6.6.||Were extra or unplanned treatments described?||Yes|
|6.7.||Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?||Yes|
|6.8.||In diagnostic study, were details of test administration and replication sufficient?||Yes|
|7.||Were outcomes clearly defined and the measurements valid and reliable?||???|
|7.1.||Were primary and secondary endpoints described and relevant to the question?||Yes|
|7.2.||Were nutrition measures appropriate to question and outcomes of concern?||Yes|
|7.3.||Was the period of follow-up long enough for important outcome(s) to occur?||Yes|
|7.4.||Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?||???|
|7.5.||Was the measurement of effect at an appropriate level of precision?||???|
|7.6.||Were other factors accounted for (measured) that could affect outcomes?||Yes|
|7.7.||Were the measurements conducted consistently across groups?||Yes|
|8.||Was the statistical analysis appropriate for the study design and type of outcome indicators?||Yes|
|8.1.||Were statistical analyses adequately described and the results reported appropriately?||Yes|
|8.2.||Were correct statistical tests used and assumptions of test not violated?||Yes|
|8.3.||Were statistics reported with levels of significance and/or confidence intervals?||Yes|
|8.4.||Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?||N/A|
|8.5.||Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?||No|
|8.6.||Was clinical significance as well as statistical significance reported?||Yes|
|8.7.||If negative findings, was a power calculation reported to address type 2 error?||Yes|
|9.||Are conclusions supported by results with biases and limitations taken into consideration?||Yes|
|9.1.||Is there a discussion of findings?||Yes|
|9.2.||Are biases and study limitations identified and discussed?||Yes|
|10.||Is bias due to study's funding or sponsorship unlikely?||Yes|
|10.1.||Were sources of funding and investigators' affiliations described?||Yes|
|10.2.||Was the study free from apparent conflict of interest?||Yes|