EE: Thermic Effect of Food (2014)


Belko AZ, Barbieri TF. Effect of meal size and frequency on the thermic effect of food. Nutrition Res. 1987;7:237-242

Study Design:
Non-Randomized Crossover Trial
C - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
Compare the thermic effect of two large meals, each representing 50% of the daily energy intake with thermic effect of four small meals each representing 25% of daily energy needs.


  • TEF: Is expressed as increase in VO2 consumption from rest
  • Energy content of the test meal: Expressed as percentage of daily energy requirement, this equation was developed; 0.832 (energy content as percentage of daily requirement) -0.01 (energy content as percentage of daily requirement)- 6.21
  • Total 10-hour TEF: [VO2 area under the 600-minute TEF curve - (RMR VO2) (600 min)]
  • TEF for each individual meal: [VO2 area under individual meal curve - (RMR VO2) (number of minutes after meal)].
Inclusion Criteria:
  1. Understand and give written consent
  2. Healthy
  3. Pass pre-study screening tests which included hematological and biochemical measures, physical examination and ECG.
Exclusion Criteria:
  1. Refusal to consent
  2. Not meeting inclusion criteria
  3. Unhealthy.
Description of Study Protocol:


  • Height measured: Not specified
  • Weight measured: Likely
  • Fat-free mass measured: Indirectly by densitometry.


  • Monitored heart rate: No
  • Body temperature: No
  • Medications administered: No.

Resting Energy Expenditure

  • IC type: Horizon Sensormedics
  • Equipment of Calibration: Yes
  • Coefficient of variation using standard gases: No
  • Rest before measure (state length of time rested if available): Yes; 60 minutes
  • Measurement length: 10 minutes for post-prandial measures
  • Measurement duration: 10 hours
  • Steady state: Likely
  • Fasting length: 12 hours
  • Exercise restrictions XX hours prior to test: Yes; 24 hours
  • Room temp: Not specified
  • Number of measures within the measurement period: Six minutes; measured every 30 minutes for 150 minutes following each 25% meal and 300 minutes following each 50% meal
  • Were some measures eliminated: No
  • Were a set of measurements averaged?
  • If averaged, identify length of each measure and number of measurements?
  • Coefficient of variation in subjects’ measures: Not specified
  • Training of measurer: Not specified
  • Subject training of measuring process: Yes.


Received standardized meals of daily energy needs as either two large meals (50% of energy needs at each meal) or four small meals (25% of energy needs at each meal) providing 15% protein, 35% fat kcal and 50% CHO kcal.

Data Collection Summary:

Outcomes and Other Measures

  • Measured REE [VO2 (L per minute), VCO2 (L per minute; ml per kg per minute), RQ, ventilation (L per minute)]
  • Independent variables of weight, height, age, BMI and fat-free mass, fat mass.
  • Blinding used: No.
Description of Actual Data Sample:
  • 12 healthy weight-stable males
  • 18 years to 34 years; mean age, 25±1.5 years

Statistical Tests

Difference between the meal patterns was assessed for significance at P<0.05 using a paired T-test.

Summary of Results:


Men Mean ±SEM
Weight (kg) 74.2±3.7
Height (cm) 182±2.1
BMI 21.6±2.7
Body fat percentage 16.7±2.0
Estimated daily energy requirement (kcal per day) 3,000±142

Steady state: Not specified. 

VO2 Consumption Results

Four meals
Oxygen consumption increased initially and declined in response to each of the four individual meals, resulting in four distinct peaks. VO2 consumption declined only slightly during the five-hour post-prandial period.

Two meals
VO2 increased only slightly after the second large meal and thus two peaks were not discernible.

Although the shape of the oxygen consumption response curves varied between the treatments, total 10-hour TEF (liters) did not: Total mean±SEM increase in O2 consumption was 43.43±5.01 and 43.42±4.72 for the four small and two large meals, respectively. This represented 210kcal or approximately 7% of the test meal.

[This TEF was followed for 2.5 hours after ingestion of the last of the small meals and five hours after the second of the larger meals; TEF underestimation error may have been greater from small meal pattern.]

Measurement Process
Length of measurements: Six-minute measures every 30 minutes for either 150 minutes or 300 minutes.
Author Conclusion:

As stated by the author in body of report:

  • "In our study, although total daily TEF was predicted to be greater from 4 small meals than from 2 large meals, no difference was found in 10-hour TEF between the small and large meals patterns."
  • “Previous research made an assumption that 3-hour TEF represented total TEF response to each of 3 energy intake levels (15, 30 and 45% of daily energy needs), VO2 consumption following the test meals returned to preprandial levels for only the 15% energy needs meal content and remained elevated for meals providing 30 and 45% of energy needs... thus 3-hour TEF underestimated total TEF in response to the greater energy needs.”
  • “In the present study, the 10-hour measurement of the daily TEF response represented a more complete assessment of the total TEF response... it is difficult to measure the extent of this underestimation [since] TEF was followed for 2.5 h after ingestion of the last of the small meals and for 5 h after the second of the large meals. The error may have been greater for the small meal pattern because of the positive linear and negative quadratic relationship between meal size and TEF...”
  • The similar results for the two meal patterns in the present study suggest that meal patterning is an unimportant consideration to either minimize or maximize TEF.
Funding Source:
Reviewer Comments:


  • TEF measured for 10 hours
  • Standardized day prior to measure intervening variables of ETOH, exercise and meals
  • Provided definitions.

Generalizability or Weaknesses

  • US-residing non-obese males
  • Study biases include convenience sampling
  • These are important variables on REE measurement accuracy: Define steady state or report baseline measurement length. However, they do reference the 1986 study.
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? N/A
  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? 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? No
  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