Accuracy of RMR Equations

[Guest guest]

I have found the HB equation to be more inaccurate amongs the obese and

the thin. In the middle of the curve, it does better, but some data

say as much as 36% off toward the outliers, especially the very obese of

thin. As a thin person, I think that is where the error is in my % of

CR.

Jeff

This is the reference for the one I mentioned where the actual RMR for

the indivudals ranged around +/- 30% than the RMR from the HB equation.

, G. et al. (1988). Resting Energy Expenditure, Body Composition,

and Excess Weight in the Obese. Metabolism, 37(5), 467-472.

Some others..

J Am Diet Assoc. 2003 Sep;103(9):1152-9.

Validation of several established equations for resting metabolic rate

in obese and nonobese people. enfield DC, Rowe WA, JS,

Cooney RN.

Department of Clinical Nutrition, Milton S. Hershey Medical Center,

Hershey, PA 17033, USA. Dfrankenfield@...

OBJECTIVE: To evaluate several equations for predicting resting

metabolic rate against measured values in obese and nonobese people.

DESIGN: Resting metabolic rate was measured with indirect calorimetry.

Four calculation standards using various combinations of weight, height,

and age were used to predict resting metabolic rate: a) -Benedict

equation, -Benedict equation using adjusted body weight in

obese individuals, c) Owen, and d) Mifflin. Main outcome was percentage

of subjects whose calculated metabolic rate was outside a +/-10% limit

from measured values. Subjects/Setting 130 nonhospitalized adult

volunteers grouped by degree of obesity (range of body mass index, 18.8

to 96.8). Statistical Analysis Performed Analysis of proportions was

used to determine differences in the percentage of subjects estimated

accurately by each equation; alpha was set at 0.05. RESULTS: Calculated

resting metabolic rate was more than 10% different from measured in 22%

of subjects using the Mifflin equation, 33% using the -Benedict

equation (P=.05 vs Mifflin), and 35% using the Owen equation (P<.05 vs

Mifflin). The error rate using -Benedict with adjusted weight in

obesity was 74% (vs 36% in obese subjects using actual weight in the

standard -Benedict equation). APPLICATIONS/CONCLUSION: Of the

calculation standards tested, the Mifflin standard provided an accurate

estimate of actual resting metabolic rate in the largest percentage of

nonobese and obese individuals and therefore deserves consideration as

the standard for calculating resting metabolic rate in obese and

nonobese adults. Use of adjusted body weight in the -Benedict

equation led to less overestimation by that equation in obese people at

the expense of increased incidence of underestimation.

PMID: 12963943 [PubMed - indexed for MEDLINE]

Eur J Clin Nutr. 2001 Mar;55(3):208-14. Related Articles, Links

Measured and predicted resting metabolic rate in Italian males and

females, aged 18-59 y.

De Lorenzo A, Tagliabue A, Andreoli A, Testolin G, Comelli M, Deurenberg

P.

Department of Human Physiology and Nutrition, University Tor Vergata,

Rome, Italy. delorenzo@...

OBJECTIVES: To determine the resting metabolic rate in a sample of the

Italian population, and to evaluate the validity of predictive equations

for resting metabolic rate (RMR) from the literature in normal and obese

subjects. DESIGN: Cross-sectional observational study. SETTINGS:

Department of Human Physiology and Nutrition, University 'Tor Vergata',

Rome. SUBJECTS: A total of 320 healthy subjects, 127 males and 193

females, aged 18-59 y. METHODS: Weight, height and resting metabolic

rate by indirect calorimetry were measured. Resting metabolic rate was

also predicted using equations from the literature. RESULTS: Resting

metabolic rate (mean s.d.) in normal weight subjects was 7983+/-1007

kJ/24 h (males) and 6127 907 kJ/24h (females). Measured RMR and

predicted RMR values using various equations from the literature were

significantly different in males and females, except for the

-Benedict equation and the Schofield equations. Also, in

overweight and obese subjects the prediction error was generally larger

compared to normal-weight subjects for all formulas except for the

-Benedict and Schofield formulas. In overweight and obese males

but not in females, RMR was lower than in normal-weight subjects after

correcting for weight and age differences. Stepwise multiple regression

of resting metabolic rate against weight, height and age in males and

females did not reveal a prediction formula with a lower prediction

error than the -Benedict or Schofield formulas and thus was not

further explored. CONCLUSIONS: The -Benedict formula and the

Schofield formula provide a valid estimation of resting metabolic rate

at a group level in both normal-weight and overweight Italians. However,

the individual error can be so high that for individual use a measured

value has to be preferred over an estimated value.

AN OLDIE..

American Journal of Clinical Nutrition, Vol 40, 168-182, Copyright ©

1984 by The American Society for Clinical Nutrition, Inc

The Benedict equation reevaluated: resting energy requirements

and the body cell mass

AM Roza and HM Shizgal

The Benedict equations (HBE) were derived from indirect

calorimetric data obtained in 239 normal subjects. Using these data and

additional data published by Benedict, which were obtained from subjects

spanning a wider age range (n = 98), the present study evaluated the

relationship between measured resting energy expenditure and age, sex,

and predicted body cell mass (BCM). When the additional subjects from

the subsequently published series are included, the regression

equations, standard error of the estimate, and 95% confidence limits are

similar to the original equations. The HBE estimate resting energy

expenditure of a normal subject with a precision of 14%. Resting energy

expenditure is directly related to the size of the BCM and is

independent of age and sex. The variables of height, weight, age, and

sex in the HBE reflect the relationship between body weight and the BCM.

Indirect calorimetry and body composition measurements were performed in

both normally nourished and malnourished patients (n = 74) to assess the

accuracy of the HBE in malnourished patients. Malnutrition is associated

with an increase in resting oxygen consumption (VO2) which becomes

apparent only when VO2 is expressed as a function of the BCM. There is

no difference in resting VO2 between the sexes when expressed as a

function of BCM. A regression equation was derived from the

Benedict data to predict resting VO2 from age, height, weight, and sex.

Predicted VO2 was not significantly different from measured VO2 for the

normally nourished patients (n = 33) whereas in the malnourished (n =

41) predicted VO2 underestimated the measured value. The HBE accurately

predict resting energy expenditure in normally nourished individuals

with a precision of +/- 14%, but are unreliable in the malnourished

patient.