Time Restricted Eating for Metabolic and Psychological Optimization: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Time Restricted Eating for Metabolic and Psychological Optimization (NCT05997316), a na na study. The primary outcome is Change in Memory Composite Rank.

2. Clinical Question

3. Trial Design

This is a completed behavioral intervention study recorded as single group, with enrollment listed as 33. The intervention is time restricted eating for a planned 12 weeks. Participants were to work with a clinical psychologist each week to modify eating times toward a 16-hour fast on 2-3 days per week. The registry lists no masking and records allocation as NA. No comparator group is described, so the design is not a randomized comparison and does not support a direct contrast with a concurrent control group.

The study's stated focus is feasibility and acceptability of the intervention among individuals with mild cognitive impairment. Changes in cognitive and metabolic function were also to be examined. The listed conditions are mild cognitive impairment and obesity. The registry names a University of North Carolina, Chapel Hill sponsor and records the study as completed. The start date is 2023-08-07 and primary completion is 2025-06-26.

The primary outcome is Change in Memory Composite Rank, assessed at baseline and 12 Weeks. Secondary outcomes are Change in Metabolic Function Composite Rank and Change in Inflammatory Function Composite Rank. The record lists four outcome measures and four analyses, but does not give numerical outcome findings, analysis populations, or participant flow through the assessments. Protocol details beyond the intervention description and outcome descriptions are not reported in the registry record. In particular, the record does not report a sample-size justification or detailed statistical analysis plan.

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

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.

6. Primary Endpoint

The registry lists the primary outcome as Change in Memory Composite Rank, measured over Baseline, 12 Weeks.

The primary endpoint is Change in Memory Composite Rank, measured at baseline and 12 Weeks. Participants completed two learning and memory assessments at each time point: the Hopkins Verbal Learning Test Revised and the Brief Visual Memory Test - Revised. Each assessment yields scores for total learning, retention, and recognition of learned items following a delay. The six scores were ranked at each time point and averaged to create a single Memory performance score. Higher scores reflect higher Memory performance.

The registry describes the 12-week mean rank as the outcome and baseline Memory performance as a control variable. It states that larger mean ranks at 12 weeks indicate greater improvements. This rank-based construction combines information across the verbal and visual memory scores on a common relative scale. The record notes that the measure has no fixed theoretical upper or lower bound, which is important when interpreting the scale: a mean rank is not a score with a stated maximum or a direct unit of memory change.

The endpoint is relevant to the study's stated interest in cognitive change during the intervention. However, its numerical estimate and confidence interval are not reported in the registry record. The record also does not report the instrument-level results or explain how any missing assessment data were handled.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean rank represent?

In general, ranking replaces the original measurements with their relative positions within the set being ranked. The registry says that six scores from verbal and visual learning and memory assessments were ranked at each time point and averaged into a Memory performance score. The resulting mean rank is therefore not expressed in the original test units. The record explicitly notes that the rank-based outcome has no fixed theoretical upper or lower bound. Higher values are described as reflecting higher Memory performance, and larger mean ranks at 12 weeks indicate greater improvements under the stated analysis.

Rank-based summaries can be useful when an analysis is intended to emphasize ordering rather than the size of differences in the original measurement units. They do not, by themselves, show how large an underlying change is in a clinically interpretable unit. The registry does not explain why ranking was selected, provide instrument-level distributions, or report the observed mean ranks.

What does baseline adjustment mean?

The registry describes the 12-week Memory mean rank as the outcome while controlling for baseline Memory performance. In general, baseline adjustment accounts statistically for the starting value when estimating the outcome at follow-up. It is different from simply subtracting a baseline summary from a follow-up summary. Adjustment can improve precision in some settings, but its consequences depend on the model and data. The model specification, coefficient, and uncertainty estimate are not reported in the registry record, so the exact adjustment cannot be reconstructed.

Baseline adjustment does not create a control group. In a single-group study, an adjusted follow-up estimate remains a description of outcomes within the intervention group. It does not, on its own, establish what would have happened over the same period without the intervention.

How should a confidence interval be read?

The primary outcome is described using a 95% Confidence Interval. In general, a confidence interval communicates the statistical uncertainty around an estimate under the assumptions of the analysis. A narrower interval indicates greater precision for that estimate, while a wider interval indicates greater uncertainty. It is not a guarantee that the true value lies within the particular calculated interval. The endpoints of the primary outcome interval are not reported in the registry record, so its precision cannot be assessed.

Interpretation also depends on the meaning and scale of the estimate. For a mean rank, the interval would be on the rank-based scale, not in the original memory-test units. No numerical estimate or interval is available in the record to compare with any threshold or to characterize its direction.

What does the single-group design allow?

In general, a single-group design can describe participation, acceptability, and changes observed over time within the group studied. It does not provide a concurrent counterfactual comparison. Without a control group, a pre-to-post pattern cannot distinguish intervention-related change from other influences, such as background changes over time or variation in repeated measurement. This is a design limitation, not a claim about the direction of any unreported result.

The registry records allocation as NA, masking as none, and the model as single group. It does not report additional design safeguards or a detailed analysis plan. Therefore, the record does not establish whether other methods were used to address bias or confounding.

How should planning illustrations be interpreted?

In general, power calculations estimate the sample size needed under specified assumptions to detect a chosen effect with a chosen probability. They are planning exercises, not measures of what a completed study actually achieved. The assumptions recorded for the illustration specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The framework is not the trial's single-group design. The record does not report the resulting planning counts or the observed effect value used for the illustration. Any participants-per-arm illustration therefore cannot be read as the study's actual allocation, enrollment, or observed power.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary Memory Composite Rank outcome, secondary metabolic and inflammatory composite-rank outcomes, four outcome measures, and four analyses. When several outcomes or analyses are examined, the chance of at least one apparently notable result can increase if each is evaluated separately. In general, multiplicity procedures can address this by adjusting testing thresholds or by specifying a hierarchy of outcomes. Whether such procedures were used is not reported in the registry record. The record does not provide the analysis results needed to assess how multiplicity may affect their interpretation.

The registry describes the primary outcome and identifies the two secondary outcomes, but a complete statistical analysis plan is not reported in the registry record. It does not state whether outcomes were prespecified in this order, how repeated measures or multiple test scores were handled beyond the described ranking, or whether any adjustment for multiple comparisons was planned or applied.

Missing-data methods are also not reported in the registry record. The enrollment figure does not indicate how many participants posted baseline data, completed the 12-week assessment, or contributed to each analysis. The record does not describe reasons for missing observations, imputation, or sensitivity analyses. The analysis population is not reported in the registry record; it is not clear whether the primary analysis included all enrolled participants or a subset defined by assessment completion or another criterion.

These omissions limit assessment of the robustness of any outcome estimate. They do not establish that data were missing or that a particular method was or was not used; they mean those details are unavailable in the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry lists the Time Restricted Eating group with 33 at risk for serious adverse events and 0 affected. It also lists 33 at risk for other adverse events and 0 affected. Deaths are recorded as 0. These are the figures recorded for this group; they do not provide an event-by-event description or a time-specific account.

A zero count means that no affected participants are recorded in these registry fields. It does not establish that the intervention carries no risk, nor does it show how thoroughly adverse events were sought or whether all participants had complete safety follow-up. The registry record does not report the definitions used for serious or other adverse events, the observation period for these summaries, or details of event monitoring. The listed at-risk figures should not be treated as confirmation that every enrolled participant contributed complete safety information.

These safety counts describe the record, not a comparison with an untreated or alternative-treatment group. With no comparator listed, they cannot be used to estimate a comparative safety difference. They also do not establish that any unreported symptoms or events did not occur.

12. What the Result Does, and Does Not, Mean

The registry record establishes that a completed, single-group study was registered to examine a 12-week time restricted eating intervention among individuals with mild cognitive impairment. It identifies feasibility and acceptability as central aims and names cognitive and metabolic changes as additional areas of interest. It also specifies the construction of a baseline-adjusted Memory Composite Rank outcome and lists metabolic and inflammatory composite-rank outcomes.

The registry record does not report numerical outcome results. It therefore does not show the observed degree of change in memory, metabolic function, or inflammatory function. Nor does it report numerical feasibility or acceptability findings. The description of an endpoint is not itself evidence of a particular outcome, and completion status does not indicate what the results were.

Even if numerical before-and-after results were available, the single-group design would constrain their interpretation. Change over time in participants cannot be separated from other influences using a concurrent control comparison because no comparator group is listed. The record's lack of reported analysis details and participant flow further limits assessment of uncertainty, missing data, and the population contributing to the estimates.

The absence of reported results in the registry record should not be interpreted as evidence of no change, and the zero adverse-event counts should not be interpreted as proof of no risk. Those are limits of what can be concluded from the recorded information, not findings about unreported outcomes. The most defensible reading is descriptive: the record documents the study's purpose, intervention, design, and outcome definitions, while leaving the numerical efficacy, feasibility, acceptability, and precision findings unavailable.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of how study design determines what a result can answer. The registry describes a single-group behavioral intervention and identifies outcomes intended to track change from baseline to 12 weeks. Such a design can describe what was observed among participants, but it cannot make a direct comparison with what would have happened in a concurrent control group. That distinction matters when interpreting any apparent change over time.

The memory endpoint also illustrates a measurement choice with consequences for interpretation. Six learning and memory scores are ranked and averaged to create one performance measure. This produces a relative rank-based outcome, rather than a measure in the original test units. The record says that higher scores indicate higher performance and notes that the scale has no fixed theoretical bounds. Statistical estimates on this scale should therefore be interpreted as rank-based, not as direct changes in raw test scores.

Baseline adjustment is another important feature: the registry describes a 12-week outcome adjusted for baseline Memory performance. A reader needs the model specification and estimate to understand the size and uncertainty of that adjustment, but those details are not reported in the registry record.

Finally, a planning illustration based on a two-arm framework should not be mistaken for the design or evidence of this single-group study. Planning calculations and observed results answer different questions. The registry does not report the numerical outcome estimates, uncertainty intervals, or planning counts, so the record illustrates the importance of distinguishing design description from inferential results.

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 registry record does not report numerical results for the primary memory outcome or the listed secondary outcomes. It also does not report numerical findings for feasibility or acceptability, although these are central aims. Consequently, the size, direction, and precision of observed changes cannot be assessed from the registry record.

The study is described as single group, with no comparator listed, allocation recorded as NA, and masking recorded as none. The design therefore does not provide a concurrent control comparison. Any change over time would be vulnerable to influences that cannot be separated from intervention-related change within this design.

Participant flow and analysis denominators are not reported. Enrollment is listed as 33, but the record does not say how many participants completed the baseline or 12-week assessments, or how many contributed to each outcome. Missing-data handling and the analysis population are also not reported. The statistical model and detailed analysis plan are not reported beyond the description of baseline adjustment for the primary outcome.

The registry lists four outcome measures and four analyses, but multiplicity procedures are not reported. The measurement description gives a rank-based composite, but no numerical instrument-level findings or rationale for ranking is reported. Safety summaries list zero affected participants for serious and other adverse events and zero deaths, but event definitions and safety follow-up details are not reported in the registry record. Together, these gaps limit independent assessment of outcome precision, robustness, and completeness.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Time Restricted Eating for Metabolic and Psychological Optimization — NCT05997316.
• Registry record last updated 2026-06-24; status last verified 2025-08.
• Results first posted 2026-03-27.
• 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.

18. Record Summary

The registry record describes a completed, single-group behavioral study titled Time Restricted Eating for Metabolic and Psychological Optimization. It lists enrollment of 33 and the conditions mild cognitive impairment and obesity. The intervention description specifies a 12-week time restricted eating program, with weekly support from a clinical psychologist to work toward a 16-hour fast on 2-3 days per week.

The primary outcome is Change in Memory Composite Rank, using baseline and 12-week assessments and a baseline-adjusted analysis as described in the record. Secondary outcomes concern metabolic and inflammatory function. The record lists four outcome measures and four analyses, but numerical outcome results, participant flow, missing-data methods, and a detailed statistical plan are not reported in the registry record.

The study is recorded as completed, with no comparator group listed. Safety fields record zero affected participants for serious and other adverse events and zero deaths. These entries are descriptive and do not establish comparative safety or the completeness of follow-up.