Protein Bioavailability of Wolffia Globosa (Mankai); Acute Test Meal Effects: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Protein Bioavailability of Wolffia Globosa (Mankai); Acute Test Meal Effects (NCT03020225), a randomized na study. The primary outcome is Amino Acid Profile (Blood Biomarkers).

2. Clinical Question

3. Trial Design

The registry record describes a randomized, parallel-group trial with no masking. It lists the study as completed, with an enrollment of 36. The study began in 2016-12 and had primary completion in 2017-02. The phase is listed as NA. The sponsor is Ben-Gurion University of the Negev.

Participants were assigned to one of three single-meal groups: white cheese, green peas, or Mankai. Each meal contained 30g of protein. The foods were consumed in the morning following 12h of fasting, with 250ml of mineral water, and blood follow-up was planned for 3 hours. This is an acute meal comparison; the record does not describe repeated meals or longer-term exposure.

Posted primary-outcome summaries include 12.0 participants in the white-cheese group, 11.0 in the green-peas group, and 13.0 in the Mankai group. The record does not explain why these group counts differ or whether every randomized participant contributed to every outcome. Eligibility criteria beyond men with mild abdominal obesity, the randomization procedure, and any allocation-concealment process are not reported in the registry record.

The registry record does not report the intended sample-size justification, a detailed protocol, the timing of any interim analyses, or a full statistical analysis plan. The available record therefore supports a description of the randomized design and the posted outcomes, but not a reconstruction of all planned trial procedures.

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.

Before assignment: https://www.ncbi.nlm.nih.gov/pubmed/30591380

Overall Study

Analysis population for the primary outcome, as defined in the registry: Essential amino acids (mmol/L) for the 3 groups

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.

Population: https://www.ncbi.nlm.nih.gov/pubmed/30591380

6. Primary Endpoint

The registry lists the primary outcome as Amino Acid Profile (Blood Biomarkers), measured over 3 hours.

The primary outcome is titled Amino Acid Profile (Blood Biomarkers). It is described as an amino-acid profile trajectory analyzed by metabolomics over a 3-hour timeframe. The posted numerical outcome is essential amino acids in mmol/L for the three groups, expressed as means with standard deviations.

In general, amino acids measured in blood can describe the circulating profile following a meal. Measuring a profile over time can characterize how that profile changes during the stated follow-up, rather than relying only on a single type of measurement. The registry record identifies the profile trajectory as the intended primary outcome, but the numerical summaries do not give individual time-point values or a detailed account of the trajectory. They therefore do not show how concentrations changed within each group during the 3 hours.

The choice of endpoint reflects the trial’s stated aim of examining protein bioavailability after different protein-containing foods. The posted results show group-level essential amino-acid means: 31.1 mmol/L for white cheese, 31.1 mmol/L for green peas, and 30.0 mmol/L for Mankai. These summaries describe the measured outcome in the observed groups; they do not by themselves establish a mechanism or a general conclusion about the foods. The metabolomic assay details and the specific handling of the trajectory in the analysis are not reported in the registry record.

7. Results Posted in the Registry

• Green Peas: mean 31.10 versus 31.10 on control; difference 0.00 (95% CI -3.35 to 3.35), standardized effect d = 0.00; z-test p = 1.000.
• Mankai: mean 30.00 versus 31.10 on control; difference -1.10 (95% CI -3.90 to 1.70), standardized effect d = -0.31; z-test p = 0.442.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Glycemic Profile

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Green Peas: mean 96.00 versus 97.50 on control; difference -1.50 (95% CI -10.83 to 7.83), standardized effect d = -0.13; z-test p = 0.753.
  • Mankai: mean 96.70 versus 97.50 on control; difference -0.80 (95% CI -9.94 to 8.34), standardized effect d = -0.07; z-test p = 0.864.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Green Peas and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Mankai and the control. The interval gives the range of effects that remain compatible with the data.

Lipid Profile

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Green Peas: mean 41.90 versus 45.30 on control; difference -3.40 (95% CI -11.25 to 4.45), standardized effect d = -0.35; z-test p = 0.396.
  • Mankai: mean 44.40 versus 45.30 on control; difference -0.90 (95% CI -7.93 to 6.13), standardized effect d = -0.10; z-test p = 0.802.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Green Peas and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Mankai and the control. The interval gives the range of effects that remain compatible with the data.

Liver Function

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Green Peas: mean 42.30 versus 43.20 on control; difference -0.90 (95% CI -15.43 to 13.63), standardized effect d = -0.05; z-test p = 0.903.
  • Mankai: mean 46.00 versus 43.20 on control; difference 2.80 (95% CI -10.17 to 15.77), standardized effect d = 0.17; z-test p = 0.672.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Green Peas and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Mankai and the control. The interval gives the range of effects that remain compatible with the data.

The registry record lists nine secondary outcomes. Numerical group summaries and unadjusted comparisons are available for glycemic profile, lipid profile, and liver function. The broader list also names other outcomes, including insulin, triglycerides, liver enzymes, minerals, and vitamins; numerical results for those outcomes are not reported in the registry record.

Across the available secondary summaries, the comparison estimates are close to zero relative to their intervals, and the intervals span values on both sides of zero. This broad pattern is consistent with uncertainty rather than a clearly resolved difference between meals. The secondary outcomes do not provide a more precise account of the primary amino-acid profile, since they measure different blood or biochemical characteristics.

In general, secondary outcomes can help describe other aspects of a trial’s measurements, but they do not replace the primary outcome question. Multiple outcomes and contrasts create multiple opportunities for apparently notable results. If each is interpreted without accounting for multiplicity, the chance of a chance finding across the set can increase. The registry record does not report a multiplicity adjustment or a hierarchy governing interpretation of secondary outcomes.

For that reason, the secondary comparisons should be read as exploratory descriptions of the posted results, not as independently confirmatory findings. Their unadjusted p-values are not evidence that all secondary outcomes are unchanged, nor do they establish that any differences are absent. The small group counts and intervals spanning both directions further limit precision. Additional outcomes listed in the record but lacking numerical results cannot contribute to an assessment of the observed pattern.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Glycemic Profile
• Lipid Profile
• Liver Function
• Minerals
• Vitamins
• Glycemic Profile-Insulin
• Triglycerides
• Liver Enzymes- ASAT

9. Statistical Interpretation

10. Statistical Methods Explained

The record identifies a randomized, parallel design and no masking. In a parallel design, participants are assigned to one group and receive that group’s test meal; the recorded arm counts are 12.0 for white cheese, 11.0 for green peas, and 13.0 for Mankai. Randomization is intended, in general, to reduce systematic differences between groups at assignment. The registry record does not describe the randomization method or how allocation was concealed.

What do the group summaries describe?

The primary outcome is a continuous measure, and the record reports the mean and standard deviation for each group. A mean describes the group’s average measured value. A standard deviation describes the spread of individual values around that group mean; it is not the uncertainty of the mean itself. For essential amino acids, the posted means are 31.1 mmol/L for white cheese, 31.1 mmol/L for green peas, and 30.0 mmol/L for Mankai. The corresponding standard deviations are 4.1, 4.1, and 2.9.

In general, the standard error reflects uncertainty in an estimated mean and depends on the variability and number of observations. It is distinct from the standard deviation. The record does not give a detailed account of which observations were included in each outcome analysis or how missing measurements, if any, were handled.

How should the comparisons be read?

The posted comparison estimates are mean differences against white cheese. For green peas, the recalculated unadjusted difference is 0.0 mmol/L, with an interval from -3.354 to 3.354 and p = 1.0. For Mankai, it is -1.1 mmol/L, with an interval from -3.905 to 1.705 and p = 0.442. These are simple unadjusted recalculations from the posted summary statistics, not reported sponsor analyses. The registry record lists no reported analyses. No discrepancy between the recalculated estimates and sponsor results is indicated in the registry record.

In general, a mean-difference estimate gives the direction and size of a contrast on the outcome’s original scale. A negative estimate means the group named in the comparison has a lower mean than the reference group; a positive estimate means a higher mean. An interval gives a range of values compatible with the estimate under the method used. Since the interval level and the method used for the posted comparisons are not described in the registry record, those details should not be assumed.

A p-value is a measure used in hypothesis testing. In general, it assesses how unusual data at least as incompatible with a null hypothesis would be if that null model were correct. It is not a measure of clinical importance and does not establish that a difference is absent. The p-values in the comparisons are unadjusted; no adjustment for the multiple outcomes or contrasts is reported.

What do the planning illustrations mean?

The sample-size planning illustrations use observed effects and state assumptions of a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. For the Mankai comparison on the primary outcome, the illustration gives 162 participants per arm for 80% power when planning for 100% of the observed effect, 287 for 75% of the observed effect, and 645 for 50% of the observed effect. These are planning illustrations, not observed power and not evidence that the trial was designed to detect those effects. The trial’s own sample-size justification is not reported in the registry record.

In general, such planning calculations illustrate how sample size depends on the assumed effect and variability. Smaller target effects require larger samples under otherwise similar assumptions. Because the illustration uses an effect observed in a small trial, it is not an independent estimate of the effect that a future study should expect. Its assumptions are stated for planning purposes and should not be mistaken for the trial’s full analysis plan.

What analysis details are unavailable?

The record does not report the statistical model used for the intended amino-acid trajectory, any covariate adjustment, the exact analysis population, missing-data procedures, interim analyses, or a prespecified multiplicity strategy. The available comparisons are unadjusted recalculations from summary statistics. They should not be described as the sponsor’s chosen inferential method. The record also does not establish whether the posted group summaries represent all randomized participants or a subset with available measurements.

11. Confidence Intervals and Precision

The primary comparison intervals are broad relative to the point estimates. For green peas versus white cheese, the recalculated mean difference is 0.0 mmol/L, with an interval from -3.354 to 3.354. For Mankai versus white cheese, the estimate is -1.1 mmol/L, with an interval from -3.905 to 1.705. Each interval includes zero and values on both sides of zero, so the posted comparisons do not precisely determine the direction of a difference.

In general, an interval expresses uncertainty around an estimate under a specified statistical method. Its width reflects the data and assumptions used, and a wider interval allows a broader range of values compatible with those data. The confidence level and interval-construction method are not reported in the registry record, so a particular confidence level should not be inferred from the interval endpoints alone.

The group sizes are 12.0 for white cheese, 11.0 for green peas, and 13.0 for Mankai. Such group sizes provide limited information for distinguishing modest differences from sampling variability. The standard deviations of the primary measure are 4.1, 4.1, and 2.9, respectively. Those summaries describe observed spread, while the intervals describe uncertainty in the comparisons; the two quantities answer different questions.

The intervals are not evidence of equivalence. An equivalence conclusion would require a prespecified margin and an analysis designed to assess whether the plausible differences fall within that margin. Such a margin and analysis are not reported in the registry record. The intervals instead show that the posted summaries leave uncertainty about the magnitude and direction of the contrasts.

12. Multiplicity, Missing Data and Analysis Populations

The record identifies one primary outcome and multiple secondary outcomes. It also contains more than one comparison against the white-cheese reference group. The comparison p-values are unadjusted, and a multiplicity strategy is not reported in the registry record. In general, when many outcomes or comparisons are examined, interpreting every unadjusted result as though it were the only test can overstate the strength of evidence. The posted p-values therefore warrant caution, particularly for secondary outcomes.

Missing-data handling and analysis populations are not described. The registry record does not say whether the primary analysis included all randomized participants, only participants with available blood samples, or another defined group. It does not report how incomplete follow-up, unusable samples, or other missing measurements were treated. The arm counts in the posted results are 12.0, 11.0, and 13.0, but the record does not explain whether those counts reflect randomization, outcome availability, or both.

The record does not report a detailed statistical analysis plan, prespecified model for the amino-acid trajectory, interim analyses, or a sample-size justification for the trial itself. These omissions make it difficult to determine which analyses were planned in advance, how the longitudinal outcome was intended to be analyzed, and whether the posted comparisons match the original analysis strategy.

In general, transparency about analysis populations, missing-data rules, and multiplicity helps readers distinguish prespecified confirmatory analyses from exploratory analyses. Without these details, the posted summaries remain useful descriptions, but they provide less information about the full inferential process. No conclusion about unreported procedures should be inferred from their absence in the registry record.

13. 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 0% reporting threshold.

The registry record reports zero serious adverse events in each group: 0 among 12 participants at risk in the white-cheese group, 0 among 11 in the green-peas group, and 0 among 13 in the Mankai group. It also reports zero other adverse events in each group and zero deaths in each group.

These counts describe the events recorded during the trial; they do not establish that no adverse events could occur. In general, when a study has a small number of participants, zero observed events still leaves uncertainty about the frequency of uncommon events. The registry record does not give a detailed adverse-event collection period, definitions, severity categories beyond serious and other events, or a narrative account of monitoring. The figures should therefore be read as event counts in this trial, not as a comprehensive assessment of safety across broader populations or longer periods.

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

The posted primary results describe essential amino-acid means after three protein-containing test meals. The white-cheese and green-pea group means were both 31.1 mmol/L, while the Mankai group mean was 30.0 mmol/L. The recalculated unadjusted comparisons have intervals that include zero and extend in both directions. These findings describe the observed groups, but they do not demonstrate that the meals produce identical amino-acid profiles.

The endpoint was intended to describe an amino-acid profile trajectory over 3 hours. The numerical summaries do not provide time-specific changes or the full trajectory, so they cannot establish when or how the profiles changed. The record also does not report the detailed metabolomic procedures or the planned statistical model for the trajectory.

In general, failure to find a clear difference is not the same as demonstrating equivalence. Establishing equivalence requires a defined margin and an appropriate analysis; these are not reported in the registry record. The unadjusted p-values should likewise not be interpreted as probabilities that the meals are the same or different.

The results concern a single acute meal under the recorded conditions: morning consumption after 12h fasting, with 250ml mineral water and blood follow-up for 3 hours. They do not establish effects of repeated consumption, longer-term outcomes, or responses in populations other than the men with mild abdominal obesity described in the record. No medical advice or treatment conclusion follows from these summaries.

15. Why This Trial Matters Statistically

This trial illustrates a distinction central to biostatistical interpretation: a point estimate, its uncertainty, and a test result each convey different information. The primary point estimate for green peas versus white cheese is 0.0 mmol/L, while the Mankai estimate versus white cheese is -1.1 mmol/L. The associated intervals cover values in both directions, so the point estimates alone should not be read as precise estimates of the underlying contrasts.

The design also highlights the limits of small acute-meal comparisons. With 12.0, 11.0, and 13.0 participants in the posted outcome groups, the trial can describe the observed group summaries, but the intervals remain informative about uncertainty. A p-value above a conventional threshold does not show equivalence or rule out differences that the study estimates imprecisely.

The planning illustrations make assumptions explicit and show how the required number of participants depends on the target effect. For the primary Mankai comparison, the illustration ranges from 162 participants per arm for 80% power at 100% of the observed effect to 645 for 50% of that effect. These are planning illustrations only, not observed power and not the trial’s reported design rationale.

Finally, the registry record demonstrates why outcome definitions, trajectory-specific methods, missing-data rules, and multiplicity plans matter. Without those details, readers should keep conclusions anchored to the posted summaries and avoid treating unadjusted comparisons as definitive evidence.

16. 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 trial is small, with 36 participants enrolled and posted primary outcome group counts of 12.0, 11.0, and 13.0. The resulting comparisons have intervals that include both negative and positive values. Precision is therefore limited, and the estimates do not establish equivalence among the meals.

The primary outcome is described as an amino-acid profile trajectory over 3 hours, but the posted numerical results are group means and standard deviations rather than time-specific trajectories. The registry record does not report the timing of blood draws, the detailed assay methods, or the statistical model used to analyze the trajectory. The available summaries cannot answer questions about the shape or timing of changes.

The study evaluates acute responses to one meal under stated fasting and meal conditions. It does not provide evidence about repeated consumption or longer-term outcomes. The recorded population is men with mild abdominal obesity; the record does not provide enough information to assess how results might apply to other groups.

Further limitations arise from unavailable reporting details. The registry record does not report the randomization procedure, allocation concealment, a sample-size justification, interim analyses, analysis populations, missing-data handling, or a multiplicity plan. The comparisons are unadjusted recalculations from posted summary statistics, and no reported analyses are listed. Numerical results are not available for all secondary outcomes named in the record. These omissions limit assessment of prespecification and completeness.

17. Related Tutorials

18. Related Statistical Calculators

19. Sources

• ClinicalTrials.gov: Protein Bioavailability of Wolffia Globosa (Mankai); Acute Test Meal Effects — NCT03020225.
• Registry record last updated 2022-04-05; status last verified 2022-01.
• Results first posted 2022-04-05.
• 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.

20. Record Summary

The completed randomized, parallel trial compared white cheese, cooked green peas, and cooked Mankai as single meals containing 30g of protein. It enrolled 36 men with mild abdominal obesity. The primary outcome was an amino-acid blood profile over 3 hours; posted essential amino-acid means were 31.1 mmol/L for white cheese, 31.1 mmol/L for green peas, and 30.0 mmol/L for Mankai.

Unadjusted recalculated comparisons against white cheese were imprecise, with intervals spanning zero. Numerical secondary summaries are available for glycemic profile, lipid profile, and liver function. Serious adverse events, other adverse events, and deaths were recorded as zero in each group. The registry record does not report key analysis details, including missing-data procedures, the trial’s sample-size justification, or a multiplicity strategy.