Adult Weight Management

Healthy Non-Obese Adults (2010-2012)

Citation:

Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals.. A reappraisal of the caloric requirements of men. Am J Clin Nutr. 1987; 46: 875-885.

Study Design:

Cross-Sectional Study

Class:

D - Click here for explanation of classification scheme.

Quality Rating:

POSITIVE: See Quality Criteria Checklist below.

Research Purpose:

To mathematically derive a predictive equation for REE based on a sample of 498 healthy normal-weight and obese individuals
Assess the usefulness of the more recent body composition measures of body composition (%BF) and distribution (WHR) in predicting REE
Assess the predictive value as well as overall practicality of the new equations compared with those currently being applied.

Definitions

Percent ideal body weight: Determined by use of the 1959 Metropolitan Height-Weight tables
Harris-Benedict equation: No definitions given
Owen equation: No definitions given
Mifflin-Jeor equation: Same as project defined
Fat-free mass calculations: Wt (kg)-fat(kg) where fat (kg) is weight(kg)x%BF.

Inclusion Criteria:

Recruitment by a 2x2x5 factorial design where sex and weight were stratified by five different age groups according to decade; bias toward the working class.

Understand and give written consent
Either the subject or spouse being employed at least half-time
Good health with less than one sick day per month for the past year
No major current illnesses or psychological problems
Extreme underweight (less than 80%IBW) or morbidly obese (more than 180%IBW).

Exclusion Criteria:

Refusal to consent
Subject or spouse not working at least part-time
In poor health.

Description of Study Protocol:

Anthropometric

Percent BF assessed using skinfold and circumference measurements taken at selected sites by trained technicians using Harpenden calipers and std techniques; sums of three SF thicknesses (i.e., thigh, triceps and suprailium for women) and (thigh, chest abdomen for men).

Height measured: Yes, nearest 0.63cm
Weight measured: Yes, nearest 0.55 with street clothes but without shoes
Fat-free mass measured: Calculated from anthropometric measurements.

Clinical

Monitored heart rate: Not reported
Body temperature: Not reported.

Resting Energy Expenditure

IC type: Metabolic measurement care with a canopy hood; standard computer programs converted O₂ and CO₂ gas exchanged into REE
Rest before measure: Relaxed, supine position with a standardized relaxation tape
Measurement length: Approximately 20 minutes per subject; measurements repeated on all subjects until a three-minute steady state was achieved
Fasting length: Overnight
Exercise conditioning 24 prior to test? Abstain from exercise 12 hours before the test
Room temp: Not reported
Number of measures repeated: Only one day for obtaining IC measurement, described in measurement length
Coefficient of variation: None reported
Equipment of calibration: “SF was key to our successful measurement by his training of our staff and high quality research methodology commitment.”
Training of measurer: Trained and certified nutritionists using a standardized protocol
Subject training of measuring process: None reported
Other: Refrain from smoking more than one hour before testing, but for 12 hours if possible.

Data Collection Summary:

Outcome(s) and Other Measures

Measured REE [(VO₂, L per minute), CO₂ (L per minute; ml per kg per minute), RER, ventilation (L per minute)]
Predicted REE using HB, Liu, WHO/FAO
Independent variables of weight, height, age, BMI and fat-free mass.

Statistical Analysis

Pearson correlation coefficients and simple and stepwise multiple regression analyses
Data analysis limited in certain circumstances because of missing data for %BF and WHR measurements
FFM regressions had N=482 of 498 subjects.

Description of Actual Data Sample:

N=508 subjects enrolled; 10 dropouts due to inability to obtain REE measurements.

Final Sample

Females
- N=247
- Mean: 44.6±14.0 years
- Range: 20 to 76 years
- 135 classified as normal weight (80 to less than 119% IBW)
- 122 classified as obese (more than 120% IBW)
Males
- N=251
- Mean: 44.4±14.3
- Range: 19 to 78
- 129 classified as normal weight (80 to less than 119% IBW)
- 122 classified as obese (more than 120% IBW).

Unplanned Exposure Factor

N=1 individual was less than 80% IBW
N=2 were more than 180% IBW.

Summary of Results:

Anthropometric

Less than 100% Ideal Body Weight	Women (N=52)	Men (N=26) Mean±SD
Weight, kg	54.9±4.5	68.5±5.8
Height, cm	164.8±5.2	178.9±6.3
%IBW	92.8±4.4	94.8±4.0
BMI	20.3±1.0	21.5±0.9
W:H ratio	0.73±0.05	0.86±0.04
% Body fat	30.0±4.5	10.7±5.3

100% to 119% Ideal Body Weight	Women (N=83) Mean±SD	Men (N=103) Mean±SD
Weight, kg	63.7±5.5	80.2±7.2
Height, cm	163.9±5.8	178.5±7.1
%IBW	108.8±5.9	110.9±5.2
BMI	23.8±1.3	25.2±1.1
W:H ratio	0.76±0.06	0.90±0.05
% Body fat	28.7±5.5	17.6±4.9

120% to 139% Ideal Body Weight	Women (N=61) Mean±SD	Men (N=82) Mean±SD
Weight, kg	76.2±6.6	92.2±7.3
Height, cm	164.7±6.4	178.0±6.3
%IBW	129.5±6.4	128.5±5.4
BMI	28.4±1.5	29.1±1.2
W:H ratio	0.80±0.07	0.93±0.05
% Body fat	36.1±4.5	21.9±5.1

140% or More Ideal Body Weight	Women (N=51) Mean±SD	Men (N=40) Mean±SD
Weight, kg	89.4±11.0	108.7±13.1
Height, cm	163.7±7.7	178.3±7.3
%IBW	153.1±11.3	151.9±10.8
BMI	33.5±2.5	34.4±2.4
W:H ratio	0.82±0.07	0.96±0.06
% Body fat	41.5±5.5	28.4±6.0

Pearson Correlation Coefficients

REE and percentage FFM was shown to correlate most highly with REE (R=0.80) for the entire group of males and females.

REE and weight: 0.72607
REE and height: 0.68669
REE and age: -0.26104
REE and %IBW: 0.35497
REE and WHR: 0.54599
FFM and weight were correlated (R=0.79)
FFM and height were correlated (R=0.81)
Sex and FFM were correlated (R=0.83)
The stepwise addition of weight, age, height and WHR increased the R2 value to 0.70; the remaining variables (sex, %IBW, and BMI) did not contribute further to the predictive value of the equation
In an assessment of men and women as a single group, weight alone yielded a R2 value of 0.56
In an assessment of men and women as a single group, FFM alone yielded a R2 value of 0.64
The R2 value of approximately 0.7 seemed to be a barrier above which we could not more accurately predict REE to conclude that there is a variability of more than 30% in REE "that cannot be explained on the basis of the variables assessed in this study ... [possibly] due to individual differences in genetically determined or acquired metabolic efficiency”
The effects of sex and obesity on REE were extensively explored by analyzing men and women, normal and overweight individuals separately. No significant differences were observed between simple regression lines for FFM in men and women within the range of values studied (males R2=0.44; females R2=0.36)
A stepwise multiple-regression analyses of subsets of the population based on sex and %IBW did not reveal any relationships or equations surpassing the predictive value of the equation considering measured weight and height and age
The R2 of 0.71 is obtained in using gender-specific equation of Mifflin-Jeor.

Clinical

Measured REE for all women (N=247) had a mean of 1,349±214kcal per day and a range of 927 to 2,216kcal per day
Measured REE for all men (N=251) had a mean of 1,776±297kcal per day and a range of 1,030 to 2,849kcal per day.

Correlation between Measured and Predicted

Mifflin-St Jeor (this study) had the best predictors of REE with the Owen equations having the least mean difference from measured REE (-4% in females and 0.1% in males)
HB significantly over-predicted REE in study populations (paired T-tests on individual means, P<0.01) by 5% and Cunningham equations significantly over-predicted REE in study population by 14% to 15% (by paired T-tests on individual means, P<0.01).

Author Conclusion:

The relationships between REE and several variables were studied to derive predictive equations for practical, clinical use in weight management today. The result of this process was to confirm EE is determined largely by FFM but is highly correlated with total body weight as well. Adding height, age and sex builds on the predictive value of weight in determining REE.
Previous findings suggest HB equation over-predicts measured REE by an average of more than 15% in modern populations. In this study, there are marked differences between means for weights and ages.
Equations are limited to their derivation from the study population; their clinical utility can be assessed by testing in other populations. Their strength and significance lie in:
- Derivation from a larger, modern-day population (stratified by age, weight and sex)
- Use of advanced equipment and technology for the measurement of actual REE
- A reasonably high correlation between REE and weight, height, and age (R2=0.71)
Direct metabolic measurements are preferable in individuals where a precise determination of REE is indicated. Other components of 24-EE (physical activity and thermic effect of food should be studied to assess more accurately the individual total daily caloric requirements)
30% unexplained variability in REE observed should be studied further.

Funding Source:

Government:	NHLBI, NIH
University/Hospital:	University of Nevada School of Medicine, and the Graduate School University of Nevada,

Reviewer Comments:

Strengths

Large sample size in comparison to other studies and stratified for age, sex and weight
Standardized measurements.

Generalizability/Weaknesses

Generalizability to study population with potential clinical utility with further validation testing
Potential for small IC inaccuracy due to lack of subject training on the procedure.

Quality Criteria Checklist: Primary Research
Relevance Questions
	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

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	N/A
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	N/A
	1.3.	Were the target population and setting specified?	N/A
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?	N/A
	2.2.	Were criteria applied equally to all study groups?	N/A
	2.3.	Were health, demographics, and other characteristics of subjects described?	N/A
	2.4.	Were the subjects/patients a representative sample of the relevant population?	N/A
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)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	N/A
	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?	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")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	N/A
	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?	N/A
	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?	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?	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?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	N/A
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	N/A
	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?	N/A
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	N/A
	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?	N/A
	7.5.	Was the measurement of effect at an appropriate level of precision?	N/A
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	N/A
	7.7.	Were the measurements conducted consistently across groups?	N/A
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?	N/A
	8.2.	Were correct statistical tests used and assumptions of test not violated?	N/A
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	N/A
	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)?	N/A
	8.6.	Was clinical significance as well as statistical significance reported?	N/A
	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?	N/A
	9.2.	Are biases and study limitations identified and discussed?	N/A
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	N/A
	10.2.	Was the study free from apparent conflict of interest?	N/A