Healthy Non-Obese Adults (2010-2012)
De Lorenzo A, Tabliabue A, Andreoli A, Testolin G, Comelli M, Deurenberg P. Measured and predicted resting metabolic rate in Italian males and females, aged 18-59 y. Eur J Clin Nutr. 2001; 55(3): 208-214.PubMed ID: 11305270
- To determine the measured RMR in a sample of the Italian population
- To evaluate the validity of predictive equations of RMR from the literature in normal and obese subjects.
- No known disease
- Not taking medication known to affect resting metabolic rate
- Able to give written consent.
Taking medication known to affect resting metabolic rate.
Procedures not specified.
- Analysis of covariance to test for differences in parameters between males and females and to test differences in RMR between normal-weight and overweight subjects
- Paired T-test to test differences between measured and predicted values
- Pearson's product-moment correlations
- Stepwise multiple regression to explore the relationship of RMR with weight, height and age within the gender groups
- Values presented as mean and standard deviation (SD).
Timing of Measurements
One measurement time.
- Measured resting metabolic rate (RMR): Calculated according to formula of Weir; only data of subjects where VO2 and VCO2 did not vary 5% from mean of 30-minute period were used in analysis:
- IC Type: Open circuit indirect calorimeter using a face mask (Sensormatic 2900)
- Rest before measurement: Prior to IC, subjects lied supine for 25 to 30 minutes in quiet room
- Length of measurement: Measured for 30 minutes
- Fast length before measurement: Overnight fast
- Room temperature: 22 degrees
- Coefficient of variation: Accuracy of gas measurements was within 4.5% of the true value and reproducibility of measurements was within 3.5%; used steady state variation within 5%
- Calibration of instrument: Daily calibration per instructions of manufacturer; for quality control, two different certified oxygen/carbon dioxide gas mixtures (SIAD Ltd Co, Rome, Italy) were used
- Training of measurer: Not reported
- Subject given prior training of IC to minimize anxiety: None reported
- Physical activity restricted: Subjects requested to refrain from physical activity prior to measurements to minimize effect of physical activity on RMR
- Steady state: Measurement VO2 and VCO2 did not vary within 5% from the mean value of 30-minute measurement period
- Predicted RMR:
- Robertson and Reid
- Fat-free mass (FFM): Calculated using the gender-specific equation of Moore et al (1963).
- Body surface area: Calculated using the formulas of Dubois and Dubois (1916).
- Body mass index (BMI) was calculated as weight/height2 (kg/m2)
- Weight measured in underwear to nearest 0.1kg
- Body height measured without shoes to nearest 0.1cm
- Subjects were categorized based on their BMI according to the WHO (1998) standards:
- Normal: BMI less than 25
- Overweight: BMI 25 or higher and less than 30
- Obese: BMI 30 or higher.
- Initial N: Not given
- Attrition (final N): N=127 males; N=193 females.
- Males: 28.7±11.4; range, 18 to 59 years
- Females: 41.4±11.5; range, 19 to 59 years
Mean BMI (kg/m2):
- Males: 26.7±4.3
- Females: 27.8±5.1
University Tor Vergata, Rome, Italy.
Correlations between measured and predicted RMR ranged from:
- In females, 0.72 for Schofield, weight alone; P<0.001 to 0.77 for Harris-Benedict, P<0.001
- In males, 0.7 for Owen et al, P<0.001 to 0.77 for Pavlou et al, P<0.001
- Measured RMR in males was 7,984kJ±1,007kJ per day (1,908kcals±240.7kcal per day)
- Measured RMR in females was 6,128kJ±907kJ per day (1,465kcals±217kcal per day)
- However, all prediction formulas significantly underestimated RMR, except for Harris-Benedict and the Schofield equations in both sexes (P<0.05).
[Editing note: Harris-Benedict overestimated in males but underestimated in females and neither estimation was statistically significant.]
- There was a large difference between measured and predicted; both males and females, especially for the Owens prediction.
Differences and Correlation Coefficients Between Measured and Predicted Resting Metabolic Rate in Males and Females
Difference (kJ) Mean (SD) Males Harris-Benedict Mifflin Owen -8 (690)NS Females Harris-Benedict Mifflin Owen
kJ per Day (SD)
Kcal per Day (SD)
Pearson Correlation Between Measured and Predicted Value
95% Confidence Interval (kJ)
1,711 (128 )
13 (644) NS
Robertson & Reid
Robertson & Reid
1Formula based on percent above ideal weight.
2Formula based on Harris-Benedict.
3Based on weight only.
4Based on weight and height.
Differences Between Measured and Predicted RMR in Males and Females, Mean Error
(Numbers are approximate as taken from a bar figure and a negative sign indicates underestimates.)
|kJ per Day||Kcal per Day|
Prediction equations from results of stepwise multiple regression:
- Males: RMR = (53.284 x weight) + (20.957 x height) - (23.859 x age) + 487
- R2=0.650, SEE 581kJ per day
- Females: RMR = (46.322 x weight) + (15.744 x height) - (16.66 x age) + 944
- R2= 0.597, SEE 581kJ per day.
- In overweight (BMI=25kg/m2) and obese subjects (BMI=30kg/m2), there was generally a larger prediction error with all equations but the estimates from Harris-Benedict and Schofield formulas were only borderline significant in obese females; both slightly underestimated the RMR (P=0.03 to 0.07). This indicates that in females, the underestimation of RMR tended to be higher in obese subjects.
- After correction for weight and age difference, the RMR in overweight and obese men were lower compared to normal-weight men
- The RMRs found in this study were higher than values reported in other, comparable populations (Schofield; Mifflin et al); however, mean weight, height and body mass index of subjects were higher compared to these populations, which could explain the higher RMR values
- Among the published RMR predicted equations, most equations underestimated RMR in males and females, whereas the Harris-Benedict and the Schofield equations resulted in rather accurate mean predicted values
- In overweight and obese subjects, the mean underestimation was generally higher in females
- In overweight males, the corrected RMR was slightly lower (P<0.01) than in normal-weight males; possibly obese subjects may have less metabolically active tissue.
- The study confirms data from the literature suggesting that Italians have relatively high RMR compared to other populations. It is likely the higher RMR is due to differences in body composition. Prediction formulas, such as Mifflin et al, generally underestimated RMR, but the Harris-Benedict and the Schofield formulas provided a valid mean estimate of RMR in both normal and overweight Italians, at a group level.
- Individual differences between measured and predicted values were high, making it necessary that in circumstances where reliable individual values are required, RMR should be measured not predicted.
|University/Hospital:||University `Tor Vergata' (Italy)|
Large sample size.
- Subjects were Italians so limited generalizability to other ethnic populations (RMR is population sensitive)
- Cross-sectional study does not allow for cause and effect
- Did not specify the number of individuals in each weight and gender category; mentioned the categories but not the specific numbers
- RMR could be influenced by leisure time physical time physical activity, dietary intake, menopausal status in women and instability of body weight. None of these were measured or controlled for in this study.
Evidence Abstractors Note (LLRY): Absolute simple differences were calculated as follows:
Measured difference/Measured RMR:
Harris-Benedict: 3/1,908kcal, *100=0.15%
Mifflin: -101/1,908kcal, *100=-5.3%
Owen: -176/1,908kcal 1,908 *100=-9.2%
Harris-Benedict: -14/1,465kcal *100=-0.95%
Mifflin: -104/1,465kcal *100=-7%
Owen: -154/1,465kcal 1,908 *100=-10.5%.
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)||Yes|
|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)||Yes|
|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?||???|
|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?||???|
|2.2.||Were criteria applied equally to all study groups?||???|
|2.3.||Were health, demographics, and other characteristics of subjects described?||???|
|2.4.||Were the subjects/patients a representative sample of the relevant population?||???|
|3.||Were study groups comparable?||???|
|3.1.||Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)||N/A|
|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.)||N/A|
|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?||???|
|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.)||???|
|3.6.||If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?||N/A|
|4.||Was method of handling withdrawals described?||No|
|4.1.||Were follow-up methods described and the same for all groups?||???|
|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%.)||N/A|
|4.3.||Were all enrolled subjects/patients (in the original sample) accounted for?||???|
|4.4.||Were reasons for withdrawals similar across groups?||N/A|
|4.5.||If diagnostic test, was decision to perform reference test not dependent on results of test under study?||N/A|
|5.||Was blinding used to prevent introduction of bias?||No|
|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.)||N/A|
|5.3.||In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?||No|
|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?||N/A|
|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?||Yes|
|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?||N/A|
|6.6.||Were extra or unplanned treatments described?||N/A|
|6.7.||Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?||N/A|
|6.8.||In diagnostic study, were details of test administration and replication sufficient?||N/A|
|7.||Were outcomes clearly defined and the measurements valid and reliable?||Yes|
|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?||N/A|
|7.4.||Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?||Yes|
|7.5.||Was the measurement of effect at an appropriate level of precision?||Yes|
|7.6.||Were other factors accounted for (measured) that could affect outcomes?||N/A|
|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)?||???|
|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?||N/A|
|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|