This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Timing of Caloric Intake, Diet-induced Thermogenesis and Hormonal Pattern (NCT02343380), a randomized na study. The primary outcome is Intra-individual Variation in Morning Diet-induced Thermogenesis (DIT) Evaluated by Calorimetric Exam After the Consumption of a Meal at 8:00 am Compared With Evening DIT Evaluated by Calorimetric Exam After the Consumption of the Same Meal at 8:00 pm.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02343380 |
| Phase | NA |
| Condition | Diet-induced Thermogenesis |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | 2 |
| Lead sponsor | University of Turin, Italy |
| Results posted | Yes |
2. Clinical Question
Population
The registry lists 20 participants and identifies diet-induced thermogenesis as the condition of interest. Further details about participant characteristics or eligibility are not reported in the registry record.
Intervention
Participants underwent indirect calorimetry after a standard meal. The morning meal was at 8:00 am, and the evening meal was at 8:00 pm. The record describes the study as randomized and crossover, with the order of morning and evening assessments varying between participants.
Comparator
The comparison is the same standard meal consumed in the morning versus in the evening, with measurements intended to be compared within the same individuals. The registry lists morning-first and evening-first sequences.
Primary question
Does diet-induced thermogenesis differ within individuals after the evening meal compared with the morning meal? The primary outcome is described as the intra-individual variation in thermogenesis. The posted results give separate morning and evening means and confidence intervals, but do not report a paired contrast or its uncertainty.
The scientific question concerns whether the timing of caloric intake is associated with a different thermogenic response after a meal. Diet-induced thermogenesis (DIT) is the energy expenditure associated with processing food, defined in this record as the difference between average after-meal and basal energy expenditure. The planned comparison keeps the meal standard while changing the time of consumption, which focuses the question on meal timing rather than on a comparison between different meals.
The registry also lists secondary questions about glucose, triglycerides, free fatty acids, insulin, leptin, glucagon-like peptide-1, acylated ghrelin, adrenalin, and noradrenalin. These concern within-person changes or morning-evening comparisons after the meal. Results for those secondary outcomes are not reported in the registry record. The available primary summaries therefore address only the posted morning and evening DIT measurements, not the wider set of hormonal and metabolic questions.
3. Trial Design
The registry describes a randomized, unmasked crossover study with an enrollment of 20. It lists the status as completed, the start as 2014-05, and primary completion as 2014-07. The sponsor is University of Turin, Italy. The phase is listed as NA. The intervention is described as a calorimetric exam after a standard meal.
In a crossover design, each participant receives or undergoes each condition, with the order varied across participants. Here, the listed sequences are morning-first and evening-first, and the clinical question compares a standard meal in the morning with the same meal in the evening. This design can support within-person comparisons: each participant can serve as their own reference, reducing the influence of stable differences between people. That advantage depends on having measurements paired by participant and an analysis that accounts for the crossover structure.
The registry's arm descriptions use the same intervention wording for both sequences: a calorimetric exam after a standard meal. The result summaries are labeled Morning and Evening, with 20 observations in each. They give a mean and a 95% confidence interval for each label. The record does not explain how those arm summaries relate to the randomized order, nor does it report a sequence-specific or period-specific analysis.
The masking field is NONE. Further information about implementation, meal composition, participant eligibility, exclusions, adherence, washout, period effects, or the sequence randomization procedure is not reported in the registry record. Those details matter when interpreting a crossover study because the timing contrast is most informative when carryover and period effects are addressed appropriately. The registry record does not state how those concerns were handled.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Morning-first, Then Evening | Evening-first, Then Morning |
|---|---|---|
| STARTED | 10 | 10 |
| COMPLETED | 10 | 10 |
| NOT COMPLETED | 0 | 0 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Morning-first, Then Evening | Evening-first, Then Morning | Total |
|---|---|---|---|---|
| Participants analysed | 10 | 10 | 20 | |
| Age, Continuous | years | 27.9 (SD 3.3) | 27.4 (SD 3.6) | 27.6 (SD 3.4) |
| Sex: Female, Male: Female | Participants | 5 | 5 | 10 |
| Sex: Female, Male: Male | Participants | 5 | 5 | 10 |
| fasting Resting Metabolic rate | Kcal/min | 1545.0 (SD 266.8) | 1540.0 (SD 235.0) | 1543.5 (SD 244.7) |
6. Primary Endpoint
The registry lists the primary outcome as Intra-individual Variation in Morning Diet-induced Thermogenesis (DIT) Evaluated by Calorimetric Exam After the Consumption of a Meal at 8:00 am Compared With Evening DIT Evaluated by Calorimetric Exam After the Consumption of the Same Meal at 8:00 pm, measured over Before and 180-min from the beginning of the meal.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | kcal/min |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the intra-individual variation in DIT after a standard meal consumed in the morning compared with the same meal consumed in the evening. The endpoint is expressed in kcal/min. According to the registry, indirect calorimetry with a Deltatrac II device measured energy expenditure before the meal and after it. DIT is defined as the difference between average after-meal and basal energy expenditure. The listed timeframe is before and 180-min from the beginning of the meal.
DIT is used as a measure of the energy expenditure response associated with eating. Comparing the same meal at different times asks whether the measured post-meal response varies with timing. The within-person framing is relevant because people's baseline energy expenditure and other stable characteristics can differ. A paired comparison can focus on the change for each participant rather than relying only on differences between group averages.
The posted results report a Morning mean of 327.5 kcal/min, with a 95% confidence interval from 279.0 to 376.0, and an Evening mean of 237.0 kcal/min, with a 95% confidence interval from 195.1 to 278.9. These are separate summaries. The registry does not report the mean within-person difference, its confidence interval, or a test of the primary contrast. Consequently, the posted values describe each condition's summary but do not give the uncertainty around the paired timing comparison.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports a Morning DIT mean of 327.5 kcal/min, with a 95% confidence interval of 279.0 to 376.0, based on 20 observations. For Evening, it reports a mean of 237.0 kcal/min, with a 95% confidence interval of 195.1 to 278.9, also based on 20 observations. The intervals describe uncertainty around the respective reported means under the analysis used to produce them. They are not confidence intervals for the within-person morning-evening difference.
The primary question is explicitly intra-individual, as expected for a crossover comparison. Yet the registry does not post a paired effect estimate, its confidence interval, a p-value, or another direct inferential result for that contrast. The difference between two group means is not a substitute for the mean of participant-level differences: those quantities can differ when the measurements are paired. No new contrast should be inferred from the two summaries alone. The registry record also does not state whether the displayed confidence intervals account for the crossover pairing.
The point estimates indicate that the posted Morning mean is higher than the posted Evening mean. This is a descriptive observation about the reported condition summaries, not a quantified estimate of the within-person timing effect. Without the paired estimate and its uncertainty, the size and precision of the primary contrast cannot be assessed from the registry record. The summaries alone also do not establish a causal interpretation, even though the study is described as randomized: the relevant analysis and details about periods and sequence are not reported.
The record lists five secondary outcomes, covering glucose and insulin AUCs, triglycerides and free fatty acid AUCs, adrenalin and noradrenalin, acylated ghrelin, and glucagon-like peptide-1. It does not report results for those outcomes. The brief summary also names leptin, but no posted leptin result is listed. The registry indicates six outcome measures in total, while giving no posted analyses. A lack of posted estimates is not evidence that an outcome had no change; it means that its result is not reported in the registry record.
The confidence intervals around the separate means are useful for understanding how precisely those means are estimated, but their overlap or separation is not the appropriate test of a paired contrast. For a crossover trial, participant-level pairing affects the variability of the contrast. The posted summaries do not provide the correlation between morning and evening measurements or the variability of individual differences. Accordingly, the statistical evidence for the primary question cannot be fully reconstructed from these results.
These findings should be read as incomplete registry reporting of a small crossover study, not as a complete account of the trial's analysis. No claim about whether meal timing changes DIT is justified by the separate means alone. The principal statistical limitation is the absence of a reported effect estimate and uncertainty for the comparison the study set out to examine.
9. Statistical Methods Explained
The reported endpoint is continuous: DIT is measured in kcal/min, and the posted summaries use means. A mean describes the average value in a group or condition. A confidence interval expresses uncertainty in an estimate; it is not a range containing most participant measurements. In this record, each condition has a reported mean and 95% confidence interval. The registry does not specify the method used to calculate those intervals.
What is the target comparison?
General statistical explanation: a crossover question is naturally expressed as a within-person contrast. For each participant, the morning measurement can be compared with that participant's evening measurement, and the set of individual contrasts can then be summarized. This preserves the pairing. A separate mean for each condition does not reveal the variability of those paired differences, because it does not show how measurements from the same person move together. The registry's primary outcome is described as intra-individual variation, but the posted results do not include the paired estimate.
Why does pairing matter?
General statistical explanation: if a participant's measurements in the two conditions tend to be similar, the within-person differences may be less variable than the measurements considered separately. If they do not tend to be similar, the paired contrast may be more variable. This relationship is represented by the within-person covariance or correlation. The record does not report that information, individual-level data, or the standard deviation of paired differences. The confidence intervals for the separate means cannot recover it on their own.
How should the confidence intervals be read?
General statistical explanation: a confidence interval summarizes the statistical uncertainty in an estimated quantity under the assumptions of the method used. A narrower interval indicates greater precision for that quantity than a wider interval, while an interval's limits do not show the distribution of individual observations. Here, the reported intervals attach to the Morning and Evening means. They do not attach to the morning-evening contrast. Comparing two separate intervals by eye is not a replacement for estimating the paired contrast and its confidence interval.
The registry gives the following summaries: Morning, mean 327.5 kcal/min with a 95% confidence interval of 279.0 to 376.0; Evening, mean 237.0 kcal/min with a 95% confidence interval of 195.1 to 278.9. Both summaries list 20 observations. No p-value or test statistic is posted for the primary comparison. No confidence interval for the intra-individual variation is posted either. Thus, the evidence available is descriptive rather than a full inferential result for the stated primary question.
What analysis details are absent?
The registry does not report the analysis model, the handling of sequence or period, assumptions about carryover, or whether any adjustment was made. For a crossover study, these details help establish whether the analysis respects the randomized order and the repeated measurements. The record also does not state how missing measurements were handled, whether all enrolled participants contributed to both summaries, or which population was used for the primary analysis. These are not details that can be inferred from the sample counts alone.
General statistical explanation: an analysis of repeated measurements may use a paired method or a model that accounts for within-participant dependence. The choice should reflect the study design and the endpoint distribution. If the data are skewed or contain influential observations, a mean-based summary may not fully describe their pattern; the registry does not provide distributional information that would allow such assessment. No alternative analysis or robustness check is reported.
What do the planning illustrations represent?
General statistical explanation: a sample-size planning illustration describes how many participants per arm a future study might require under stated assumptions about the effect to detect, significance level, allocation, and statistical approximation. It is not an observed result, and it is not the number of participants who actually experienced an outcome. The registry record states that its planning illustrations use the observed effect and are not the trial's own design justification. Any such illustration should therefore be treated as hypothetical planning, not as observed power or evidence that the study was adequately or inadequately designed.
The record does not report a sample-size justification for the trial itself. It also does not report a prespecified analysis plan or say whether any interim analyses were planned or conducted. Statistical interpretation is therefore constrained by the limited reporting: the endpoint definition and separate condition summaries are available, but the direct paired analysis and several design and analysis details are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists six outcome measures in total and five secondary outcomes. The secondary outcomes include glucose and insulin AUCs, triglycerides and free fatty acid AUCs, adrenalin and noradrenalin, acylated ghrelin, and glucagon-like peptide-1. The brief summary also names leptin among the secondary responses. Results for the secondary outcomes are not reported in the registry record.
When several outcomes are examined, the chance of at least one apparently notable result can increase if each is tested separately without a plan for controlling multiplicity. General statistical explanation: investigators may address this by identifying a primary outcome in advance, adjusting the interpretation or testing procedure for multiple comparisons, or clearly treating secondary findings as exploratory. The registry record identifies a primary outcome but does not report a multiplicity procedure, a hierarchy among secondary outcomes, or whether secondary analyses were prespecified. No adjustment should be assumed.
The record gives 20 observations for each posted primary condition summary, but it does not state how many participants had complete paired measurements or how missing data were handled. It does not report an analysis population, exclusions from analysis, or a flow of participants through the crossover periods. The separate condition counts do not establish that every participant contributed both measurements.
These omissions matter because missingness can affect a paired analysis if participants do not contribute complete measurements or if missing values are related to the outcome. General statistical explanation: complete-case analyses and methods that use incomplete repeated measurements rely on different assumptions. The record does not identify which approach, if any, was used. As a result, neither the degree of missingness nor its potential influence on the primary estimate can be assessed from the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Morning | 0 | 20 | 0.0% |
| Evening | 0 | 20 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Morning | 0 of 20 |
| Evening | 0 of 20 |
The registry lists zero serious adverse events among 20 participants in the Morning group and zero among 20 in the Evening group. These figures are counts of serious adverse events in the posted safety summaries. The record does not list any serious adverse-event terms.
The other adverse-event counts are also listed as zero among 20 participants in each group. This should be read as no events recorded in those categories in the posted results, not as proof that no event could occur or that the intervention is free of risk. The deaths field is null for both groups; deaths are therefore not reported in the registry record, rather than affirmatively reported as zero.
General statistical explanation: when no events are observed in a study of limited size, the data still leave uncertainty about the underlying event rate. A zero count does not establish that the true risk is zero. Interpretation also depends on how events were defined, collected, and monitored. Further details about safety collection and follow-up are not reported in the registry record.
The safety figures should be kept distinct from the thermogenesis outcome. They do not provide evidence about the primary endpoint, and they do not address the unreported secondary metabolic outcomes. They are a record of the adverse-event counts posted for the study, with the limitations in reporting noted above.
12. What the Result Does, and Does Not, Mean
The registry reports separate mean DIT values for morning and evening meal assessments, with 95% confidence intervals and 20 observations in each condition. The Morning summary is 327.5 kcal/min, with an interval from 279.0 to 376.0. The Evening summary is 237.0 kcal/min, with an interval from 195.1 to 278.9. Descriptively, the posted Morning mean is higher. Those summaries do not quantify the within-person contrast that defines the primary question.
The result does not show how much each participant's DIT changed between conditions, how consistent that change was across participants, or how precise the average paired change might be. No paired estimate, confidence interval, or p-value is reported. The separate condition intervals cannot fill this gap because they do not capture the dependence between measurements from the same participants.
The results also do not establish that meal timing caused a difference in DIT. Although the registry describes randomized order in a crossover design, the posted summary does not report an analysis accounting for the paired measurements, sequence, or period. Relevant design and analysis details are not reported in the registry record. The data as posted therefore support a descriptive comparison, but not a fully reported inferential conclusion about the primary timing effect.
No results are posted for the listed secondary measures. The absence of those results should not be interpreted as showing no hormonal or metabolic response. Likewise, the adverse-event counts describe the posted safety record and do not establish absence of risk. The record does not report the details needed to assess missing measurements or the population included in each analysis.
In practical statistical terms, the reported means characterize the condition-level summaries, while the primary scientific question requires a within-person estimate. The two are related but not interchangeable. The posted data are insufficient to determine the precision of the paired timing comparison or to judge its statistical evidence. The registry record should be read as an incomplete report of the planned primary comparison, not as a definitive statement about the effect of meal timing.
13. Why This Trial Matters Statistically
This trial is statistically notable because its randomized crossover design and stated primary endpoint call for a within-person analysis. In such a design, the central quantity is the change between conditions for each participant, summarized across participants. Reporting separate condition means can be informative, but it does not by itself convey the variation of those paired changes. The registry's posted result therefore illustrates why outcome summaries should align with the estimand, or target comparison, specified by the research question.
The record gives condition-specific means and confidence intervals, but does not report a confidence interval or test for the primary intra-individual variation. This gap limits assessment of precision and statistical evidence, even though the trial lists 20 observations in each condition. The sample counts do not reveal the variation of the paired differences, and they do not confirm from the record alone that the same participants contributed both measurements.
The study also lists a broad set of secondary metabolic and hormonal outcomes. Without posted results or a reported multiplicity strategy, readers cannot evaluate those questions or know how multiple comparisons were handled. This is a reporting issue as well as an analysis issue: a clearly documented primary contrast, secondary-outcome plan, and analysis population would make the registry results easier to interpret.
General statistical explanation: transparent reporting of the estimate, its uncertainty, the analysis population, and any assumptions is important because a statistically meaningful interpretation depends on more than the direction of two means. This trial record demonstrates the distinction between descriptive summaries and a direct analysis of a paired randomized comparison. It also shows why registry results should be interpreted in light of what is and is not reported, without treating missing inferential results as evidence of no effect.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The central limitation in the registry record is that the primary outcome is described as an intra-individual variation, while only separate Morning and Evening means and confidence intervals are posted. The paired contrast, its uncertainty, and any test result are not reported. The confidence intervals for the two means do not provide the uncertainty for the within-person comparison.
Participant-level data and the variability or correlation of paired measurements are not reported. The record does not clarify whether all 20 participants contributed to both conditions, how many had complete data, or how missing values were handled. It also does not identify the analysis population or report exclusions after enrollment.
Important details of the crossover implementation and analysis are not reported in the registry record. These include the handling of sequence and period effects, possible carryover, the analysis model, and the assumptions used to produce the confidence intervals. The meal composition and further details about participant characteristics and eligibility are also not reported.
The record lists secondary metabolic and hormonal outcomes but posts no results for them. It does not report a multiplicity procedure, a detailed statistical plan, or a sample-size justification for the trial. The planning illustrations described in the record are not the trial's own design justification and should not be interpreted as observed power.
Finally, the safety results contain zero counts for serious and other adverse events, while deaths are not reported. Further details about event collection and follow-up are absent. These limitations apply to interpretation of the registry record; they do not establish what analyses or information may exist outside it.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Timing of Caloric Intake, Diet-induced Thermogenesis and Hormonal Pattern — NCT02343380.
- Registry record last updated 2018-01-24; status last verified 2018-01.
- Results first posted 2015-12-31.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT02343380, titled “Timing of Caloric Intake, Diet-induced Thermogenesis and Hormonal Pattern,” is listed as a completed randomized, unmasked crossover study sponsored by University of Turin, Italy. Enrollment was 20. The registry lists the start as 2014-05 and primary completion as 2014-07.
The primary endpoint is intra-individual variation in DIT after the same standard meal at 8:00 am and 8:00 pm. DIT was defined as the difference between average after-meal and basal energy expenditure, measured by indirect calorimetry before and 180-min from the beginning of the meal.
The posted primary results are separate Morning and Evening means with 95% confidence intervals. The registry does not report a paired contrast, its uncertainty, or a p-value. Results for the listed secondary outcomes are not reported in the registry record. Serious and other adverse-event counts are listed as zero in each condition; deaths are not reported.