AzTrials
AzTrials

HealthyMeta-FastNCT07178106

Investigation of the Relationship Between Peripheral and Central Metabolic Changes Caused by Fasting

A study testing Fasting in people with Healthy, run by Nils Opel at 1 site in Germany.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

Fasting has become an increasingly popular intervention for improving both physical and mental health. This study aims to explore the biological mechanisms underlying the positive effects of low caloric fasting (Wilhelmi-Buchinger-fasting). Read more about this study

Who is it for?
Ages 18 to 40 yearsHealthy volunteers can take part
Conditions the study is for
Healthy
What is being tested?
Fasting
Could I receive a placebo?
No, everyone receives an active treatment
How many people
12 participants
Where
1 siteGermany
Study dates
4 Oct 2024to 28 Nov 2024
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 40 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Normal weight at study inclusion (BMI 18.5-25)
  • Generally good physical condition without serious previous illnesses
  • For female participants, only participants taking hormonal contraception are included

Who cannot join

  • MRI contraindication: cardiac pacemakers, hearing aids, neurostimulation, insulin pumps, other potentially ferromagnetic implants, screws, clips, prostheses, metal splinters, etc., pregnancy, claustrophobia, extensive tattoos, medication that impairs thermoregulation
  • Comorbidity: neurological or psychiatric conditions, cognitive impairments, chronic somatic disorders
  • Intake of more than 40g of pure alcohol (for men) or more than 20g of pure alcohol (for women), smoking, regular drug use
  • Pregnancy or nursing
  • Current or within the past five years eating disorder, vegan diet or fasting within the past six months
  • Regular medication intake

Trial locations and contacts

1 site in 1 country.

Germany1 site
  • Department of Psychiatry and Psychotherapy, University Hospital Jena

    Jena, Thuringia, 07743

Other trials in Germany

About this study

Fasting has become an increasingly popular intervention for improving both physical and mental health. This study aims to explore the biological mechanisms underlying the positive effects of low caloric fasting (Wilhelmi-Buchinger-fasting). Specifically, we focus on the metabolic transition from glucose to fat utilization and its effects on systemic and brain metabolism. By examining the relationship between peripheral metabolic changes and brain metabolism, this research aims to uncover how these shifts influence brain metabolism and behaviour.

Read the detailed description

Therapeutic fasting, specifically Buchinger fasting, is a widely recognized method in integrative medicine. It is frequently used to treat a variety of chronic diseases, including inflammatory and metabolic disorders. In addition to its benefits for physical health, fasting is increasingly recognized for its potential to improve mental health.

Research has shown that fasting can induce significant biological effects, including the metabolic switch, which involves the transition from glucose to fat as the primary energy source. This shift typically occurs around day two of the fasting period and has important implications for peripheral metabolism. However, little is known about how these peripheral metabolic changes are linked to brain metabolism and how this connection might affect brain network function and, ultimately, psychological and cognitive processes.

Recent studies have shown that fasting influences both peripheral metabolism and brain function, with potential benefits for mental health. The precise mechanisms and timing of these changes remain unclear. The current study will focus on understanding (i) how peripheral metabolic changes during fasting relate to central metabolic changes in the brain, (ii) how these changes affect brain network function over time, and (iii) the connection between these metabolic and functional brain changes with psychological and cognitive alterations during fasting.

This study will use detailed metabolic profiling and neuroimaging techniques, alongside psychological assessments, to explore these complex interactions in healthy, fasting individuals, providing a foundation for further research into its potential as an intervention for mental health disorders.

Conditions
Healthy
Being tested
Fasting
Keywords
Fasting, MR Spectroscopy, fMRI, Metabolism, Autophagy, Immune response
Medical subject headings
Fasting

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • FastingOther

    Also called Wilhelmi-Buchinger-fasting

    Participants undergo the standardised Wilhelmi-Buchinger fasting intervention, which consists of two days of preparation with a dietary energy supply of <1000 kcal, three days of fasting with a dietary energy supply of 300-500 kcal with tea, broth, fruit and vegetable juices, and two days of recovery.

Study groups in NCT07178106
Study groupRoleWhat they receive
Participant Group/ ArmExperimentalHealthy participants
Receives: Other: Fasting

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. MR spectroscopy

    metabolites between 0-4 ppm in regions including the posterior cingulate cortex (PCC), medial cingulate cortex (MCC), and anterior insula

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

Secondary outcomes (20)
  1. Structural MR imaging

    cortical thickness, grey matter volume

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  2. Functional MRI

    resting state functional connectivity

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  3. Exploratory Proteomics of Autophagy Processes II

    protein levels and protein phosphorylation by targeted and untargeted mass spectrometry-based proteomics and phosphoproteomics of isolated PBMCs (peripheral blood mononuclear cells)

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  4. Exploratory Proteomics of Autophagy Processes I

    protein levels of autophagy biomarkers (e.g. LC3II \& p62) of isolated PBMCs (peripheral blood mononuclear cells) by Western Blotting

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  5. Neuropsychology: Verbal Fluency

    MWT-B, Regensburg Word Fluency Test. A composite score for verbal fluency will be derived from the Regensburg Word Fluency Test and the MWT-B. First, raw scores for each test will be converted to standardized scores (e.g., z-scores). If needed, scores will be adjusted so that higher values consistently represent better performance. The standardized scores will then be averaged to create a single composite measure of verbal fluency.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  6. Neuropsychology: Memory

    VLMT-A, block span. A composite memory score will be computed from the VLM-T and Block Span test. Raw scores from each test will be standardized (e.g., into z-scores). These z-scores will then be averaged to yield a single measure of memory performance, reflecting both verbal and visuospatial working memory components.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  7. Neuropsychology: Processing speed

    Number Symbol Test, Letter-Number-Symbol Test, TMT-A. A composite score for processing speed will be derived from the Number Symbol Test, Letter-Number Symbol Test, and TMT-A. First, raw scores from each test will be normalized (e.g., converted into z-scores), taking into account that lower completion times on the TMT-A indicate better performance. The normalized scores will then be combined-after adjusting the direction of scores if necessary-by calculating their average to yield a single, unified measure of processing speed.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  8. Neuropsychology: Attention

    TMT-B, D2-Test. A composite attention score will be created using the D2-Test and TMT-B. Raw scores from both tests will be standardized (e.g., as z-scores). For tests such as the TMT-B, if necessary, the scores will be adjusted (e.g., reverse-coded) so that higher values indicate better attention performance. The resulting standardized scores will be averaged to form a unified attention measure.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  9. Sleep

    Pittsburgh Sleep Quality Index (PSQI). The 19 self-rated questions of the PSQI are grouped into 7 components. Each component is scored from 0 to 3 points. The scores of the 7 components are then summed to yield a global score ranging from 0 to 21, with higher scores indicating poorer sleep quality.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  10. Depression

    Beck's depression inventory (BDI-II). The questionnaire consists of 21 questions. Each question is scored on a 4-point scale ranging from no impairment (0) to severe impairment (3). The maximum score is 63.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  11. Anxiety

    State-Anxiety Inventory (STAI-S). For the STAI-S assessment, specific items (1, 2, 5, 8, 10, 11, 15, 16, 19, and 20) were reverse-coded because they represent aspects of anxiety expressed in a negative direction. After recoding, responses for all STAI-S items were summed to obtain the final test score for state anxiety.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  12. Anhedonia

    Snaith-Hamilton-Pleasure-Scale (SHAPS). For scoring, each non-affirmative response ("does not apply" or "does not apply at all") is assigned 1 point, while each affirmative response is assigned 0 points. The points are summed across all items, resulting in a total score ranging from 0 to 14, with higher scores indicating a greater degree of anhedonia.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  13. Life quality

    Positive Mental Health Scale. 9 items rated on a 4-point Likert scale ranging from 0 ("do not agree") to 3 ("completely agree"). A total score is computed by summing the responses to all items, with higher scores indicating greater positive mental health.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  14. Numeric Analog Scales

    Assessing mood on 0-10 points and sleep duration on 0-13 points scale

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  15. Metabolic processes

    Targeted and quantitative analysis by mass spectrometry of change in metabolites of plasma

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  16. Fatigue

    Fatigue Assessment Scale (FAS), 10-item self-assessment scale. For scoring, responses to items 1-3 and 5-9 are rated on a scale from 1 to 5, while items 4 and 10 are reverse-coded (scored from 5 to 1). The scores for all items are then summed to produce the total FAS score.

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  17. Lipid profiling

    Targeted and quantitative analysis by mass spectrometry of change in plasma lipids

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  18. Transcription expression patterns

    Change of the gene expression profile by RNA sequencing of isolated PBMCs (peripheral blood mononuclear cells)

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  19. Proteome/phosphoproteome/ubiquitinome patterns

    proteome expression patterns through blood (PBMCs and Plasma) based proteome, phosphoproteome, and ubiquitinome analysis

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

  20. Exosomal protein patterns

    Evaluate exosomal protein content through blood based metabolome analysis

    Measured: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted17 Sep 2025
  2. Study start4 Oct 2024
  3. Primary completion28 Nov 2024
  4. Study completion28 Nov 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
12 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07178106
Sponsor's protocol ID
2024-3502_1-BO
Acronym
Meta-Fast
Status last verified
Sep 2025
First submitted
17 Jan 2025
Last updated
17 Sep 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A study testing Fasting in people with Healthy, run by Nils Opel at 1 site in Germany.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 17 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

MR spectroscopy (time frame: Outcome measures are assessed as changes from baseline over 3 fasting days, with follow-up on day 4 during refeeding, during a one-week on-site visit per participant, within an overall study period of 2 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Sep 2025.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in