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EE: Harris-Benedict: Obese and Nonobese (2005)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To compare the predicted resting metabolic rate pRMR, as is estimated by the HBE, with measured resting metabolic rate mRMR, as assessed by indirect calorimetry in moderately obese male subjects.

Inclusion Criteria:

1. Understand and give written consent

2. Diseases in subjects that were allowed: free of any physical, psychological, or metabolic impairment

3. Moderately obese (21-70% above ideal body wt)

Exclusion Criteria:

1. Refusal to consent

2. Not meeting inclusion criteria

Description of Study Protocol:

Measured RER was compared with predicted RER with both current wt and ideal wt by HB equation.

Definitions:

“Steady state”- not defined

Terms:

LMB-lean body mass

AIBW-above ideal body wt

FM-fat mass

Anthropometrics

Ht measured: yes

Wt measured: yes

Fat-free mass measured: yes

CLINICAL:

Monitored heart rate? no

Body temperature? no

Medications administered? no

Resting energy expenditure:

IC type: Horizon metabolic measurement cart

Equipment of Calibration: not addressed

Coefficient of variation using std gases: not addressed

Rest before measure (state length of time rested if available): 30-45min

Measurement length: not specified

Steady state: mean values achieved during the last 10 min of steady state were used in the calculations.

Fasting length: 8-12 h

Exercise restrictions XX hr prior to test? 8-12

Room temp: not specified

No. of measures within the measurement period: not specified

Were some measures eliminated? Not specified

Were a set of measurements averaged? yes, but details were not specified

Coefficient of variation in subjects measures? no

Training of measurer? yes

Subject training of measuring process? no

DIETARY

Food intake were not controlled prior to the IC study. However, 8-12 h fast was required.

Intervening factor:

Caffeine-containing beverages were prohibited during the pre-measurement period.

Subjects did not engage in any physical activity or smoke any cigarettes during that period.

Statistical Analysis

Student’s two tailed t-test

Linear regression analysis

Multiple regression analysis

Data Collection Summary:

Outcome(s) and other measures:

1. Measured REE

2. Predicted RMR using: HB

3. Independent variables of weight, height, age, and fat-free mass, fat mass %, lean body mass

Blinding used:  None

Description of Actual Data Sample:

N= 31 males

Age ranged from 30-60 (48+/- 8.5)

Moderately obese males

Summary of Results:

ANTHROPOMETRIC

Mean ± SD

Age, y

48.5 ± 4.5

Wt, kg

107.3 ±17.1

Ht, cm

178.1 ± 5.1

AIBW%

44.5 ± 15.8

LBM, kg

68.4 ± 10.7

FM%  

36.4 ± 11.2

RMR

Measured RMR was found to be significantly lower (p<.001) than predicted RMR using current wt in HBE.

Measured RMR was significantly higher (p<.001) than predicted RMR using ideal body wt

Measured RMR was 92 +/- 10% of the pRMR (current wt) and 119 +/- 12% of the pRMR (ideal wt)

Individual variation of the mRMR ranged from 65-109% of the expected normal values, with only 64% of the having RMR within +/- 10 % of the expected.

When mRMR was expressed as percent of expected, with ideal body wt in the HBE, only 26% of the patients were found to be within +/- 10% of the expected normal , with individual variation ranging from 76 to 150% of expected value. 

Linear regression analysis showed a statistically significant (p<.001) correlation (r=.79) between mRMR and pRMR predicted by HBE.

Multiple regression analysis with ht, wt, age, and percent of above ideal body wt as independent variables showed a statistically significant (p<0.001) correlations (r=.81) between these indices and mRMR.  The regression equation resulting from our analysis:

          MRMR (kJ./day) = [2089.7 – 8,1(Ht) + 16.81 (Wt) – 8,9 (Age) – 1.03 (% AIBW) ] x 4.18

accounts for 66% of the variance in measured RMR.

 
Author Conclusion:

“The present investigation reports that even without kilojoule restriction, obese individuals are characterized by a suppressed RMR when compared to individuals of normal body wt and body composition.”

“The significant correlation coefficient of +.081 found between mRMR and age, ht, wt, and % AIBW indicates that these indices adequately predict the caloric needs of the metabolically active tissues in moderately obese male subjects.”

‘The equation developed from this study accurately predicts daily energy expenditure for moderately obese male subjects with a degree of obesity ranging from 21-70% above ideal body wt, and its concluding possible application s and ways to test their usefulness should be considered.”

Funding Source:
Industry:
Nutritional Management Inc.
Other:
University/Hospital: New England Deaconesse Hospital, Harvard Medical Center
Reviewer Comments:

Strengths:

    • Possible confounders and intervening factors were monitored, such as caffeine use, cigarette smoking, and physical activity.
    • Good study design with appropriate statistics.
    • Conclusions were supported by data.

Generalizability/Weaknesses:

  • Only applied to moderately obese men.
  • Based on only relatively small samples to formulate a equation. Validity of the equation should be assessed before use in clinical setting. Race was not considered in the generation of the equation due to the limited number of subjects. Limitations were not discussed.
  • IC protocol were not described in details (length, frequency, time of the IC studies)
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? No
  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? 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.) 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