HealthyNCT04452916
Physiological Response to 5 Days Fasting
A study testing Buchinger fasting in people with Healthy, run by Charite University, Berlin, Germany at 1 site in Germany.
Trial summary
To investigate energy metabolism, anthropometry, blood pressure, gut microbiome, serum metabolome, glucose variability and neural mechanisms of food choice and mood before and after 5 days of fasting as well as their persistence in healthy men and women. Read more about this study
- Who is it for?
- Ages 20 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Buchinger fasting
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 55 participants
- Where
- 1 siteGermany
- Study dates
- 2 Nov 2020to 1 Jul 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 20 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men and women
- 20-50 years
- Body mass index 20-30 kg/m2
Who cannot join
- Clinically relevant heart, lung, liver, and kidney diseases
- Any prescribed medication (except for oral contraceptives)
- Current or chronic infection
- Intake of antibiotics within 6 months before study entry
- Fasting week within 6 months before study entry
- Habitual use of dietary supplements
Show all 11Show fewer
- Food intolerances
- Pregnancy, lactation
- Vegan diet
- Smokers
- In addition for fMRI: sensorineural hearing loss, tinnitus, metal implants, electric devices
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Physiological Response to Prolonged Fasting in Healthy Volunteers
To investigate energy metabolism, anthropometry, blood pressure, gut microbiome, serum metabolome, glucose variability and neural mechanisms of food choice and mood before and after 5 days of fasting as well as their persistence in healthy men and women.
- Conditions
- Healthy
- Being tested
- Buchinger fasting
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Buchinger fastingOther
Caloric intake of < 250 kcal/d for 5 days
| Study group | Role | What they receive |
|---|---|---|
| Fasting | Active comparator | Starts immediately with 5 days of Buchinger fasting Receives: Other: Buchinger fasting |
| Waiting list control | Placebo comparator | Starts with 5 days of Buchinger fasting after a waiting period of 12 weeks Receives: Other: Buchinger fasting |
What is being measured
The primary outcome is the main question the study is designed to answer.
Resting Energy Expenditure
Measured by indirect calorimetry (kcal/d)
Measured: 6-th day of fasting compared to baseline
Secondary outcomes (15)
Resting Energy Expenditure - Recovery
Measured by indirect calorimetry (kcal/d)
Measured: 12 weeks after fasting compared to baseline
Resting Respiratory Exchange Ratio
Measured by indirect calorimetry
Measured: 6-th day of fasting and 28 days after fasting compared to baseline
Office systolic blood pressure
Mean of five consecutive blood pressure measurements (mmHg)
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Office diastolic blood pressure
Mean of five consecutive blood pressure measurements (mmHg)
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Fecal microbiome composition
Measured by 16S Sequencing
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Fecal and serum metabolome
Measured by mass spectrometry
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Change in immune cell phenotypes
Peripheral blood effector T cell frequencies (Percent)
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Glucose variability
Measured by continuous glucose monitoring over 14 days
Measured: From 3 days before until 6 days after fasting
Neural correlates of emotion processing
Measured by functional Magnetic Resonance Imaging
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Neural correlates of food-specific delay discounting
Measured by functional Magnetic Resonance Imaging
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Perceived Stress Questionaire (PSQ)
Range 0-100, with 0 indicating no perceived stress
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Perceived Self Efficiency
Range 10-40, with 40 indicating highest self efficiency
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
PANAS Positive Affect Subscale (GESIS Panel)
Range 10-50, with 50 indicating highest positive affect
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
PANAS Negative Affect Subscale (GESIS Panel)
Range 10-50, with 50 indicating highest negative affect
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
International Physical Activity Questionaire (IPAQ, long version)
Time for moderate and vigorous activity (hours, minutes)
Measured: 6-th day of fasting and 12 weeks after fasting compared to baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jul 2020
- Study start2 Nov 2020
- Primary completion14 Dec 2022
- Study completion1 Jul 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by Charite University, Berlin, GermanyThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Randomised
- Intervention model
- Parallel groups
- Model description
- Waiting list control group
- Masking
- None (open label)
- Enrolment
- 55 participants (actual)
Sponsor and investigators
- Lead sponsor
- Charite University, Berlin, Germany
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sylvia Bähring, PhD, Charite University, Berlin, Germany
- Investigators
- Sylvia Bähring, PhD, Principal investigator, Charite University, Berlin, Germany
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04452916
- Sponsor's protocol ID
- LEANER
- Status last verified
- Aug 2024
- First submitted
- 23 Jun 2020
- Last updated
- 21 Aug 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data that underlie the results of reported articles (text, tables, figures, supplemental data) will be shared after deidentification.
Publications
Kaufhold G, Bartolomaeus TUP, Schutte K, Schutte T, Kamboj S, Lober U, Rahn G, McParland V, Braun L, Marko L, Mammadli M, Krannich A, Bahr LS, Gutmann F, Paul F, Ducarmon QR, Zeller G, Mesnage R, Wilck N, Zernecke A, Oefner PJ, Gronwald W, Muller DN, Forslund-Startceva SK, Bahring S, Bartolomaeus H, Siebert N. Machine learning identifies microbiome and clinical predictors of sustained weight loss following prolonged fasting. Genome Med. 2026 Sep 16;18(1):136. doi: 10.1186/s13073-026-01765-0.
PubMed 42754908
Study at a glance
From the registry record, last updated by the sponsor on 21 Aug 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Physiological Response to Prolonged Fasting in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT04452916
- Acronym / sponsor ID
- LEANER
- Conditions
- Healthy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 55 participants (actual)
- Lead sponsor
- Charite University, Berlin, GermanyUniversity, hospital or other
- Study start
- 2 Nov 2020 (actual)
- Primary completion
- 14 Dec 2022 (actual)
- Study completion
- 1 Jul 2024 (actual)
- First posted
- 1 Jul 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To investigate energy metabolism, anthropometry, blood pressure, gut microbiome, serum metabolome, glucose variability and neural mechanisms of food choice and mood before and after 5 days of fasting as well as their persistence in healthy men and women.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Waiting list control group
| Arm | Type | Receives |
|---|---|---|
| Fasting | Active comparator | Other: Buchinger fastingStarts immediately with 5 days of Buchinger fasting |
| Waiting list control | Placebo comparator | Other: Buchinger fastingStarts with 5 days of Buchinger fasting after a waiting period of 12 weeks |
Who may qualify
- Ages
- 20 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Men and women
- 20-50 years
- Body mass index 20-30 kg/m2
Key exclusion criteria (11 listed)
- Clinically relevant heart, lung, liver, and kidney diseases
- Any prescribed medication (except for oral contraceptives)
- Current or chronic infection
- Intake of antibiotics within 6 months before study entry
- Fasting week within 6 months before study entry
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Buchinger fastingCaloric intake of < 250 kcal/d for 5 days | Other | Fasting, Waiting list control |
Primary outcome
Resting Energy Expenditure
Time frame: 6-th day of fasting compared to baseline
Measured by indirect calorimetry (kcal/d)
15 secondary outcomes
Resting Energy Expenditure - Recovery
Time frame: 12 weeks after fasting compared to baseline
Resting Respiratory Exchange Ratio
Time frame: 6-th day of fasting and 28 days after fasting compared to baseline
Office systolic blood pressure
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Office diastolic blood pressure
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Fecal microbiome composition
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Fecal and serum metabolome
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Change in immune cell phenotypes
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Glucose variability
Time frame: From 3 days before until 6 days after fasting
Neural correlates of emotion processing
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Neural correlates of food-specific delay discounting
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Perceived Stress Questionaire (PSQ)
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Perceived Self Efficiency
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
PANAS Positive Affect Subscale (GESIS Panel)
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
PANAS Negative Affect Subscale (GESIS Panel)
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
International Physical Activity Questionaire (IPAQ, long version)
Time frame: 6-th day of fasting and 12 weeks after fasting compared to baseline
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Aug 2024.
- Derived from this study: PubMed 42754908Kaufhold G, Bartolomaeus TUP, Schutte K, Schutte T, Kamboj S, Lober U, Rahn G, McParland V, Braun L, Marko L, Mammadli M, Krannich A, Bahr LS, Gutmann F, Paul F, Ducarmon QR, Zeller G, Mesnage R, Wilck N, Zernecke A, Oefner PJ, Gronwald W, Muller DN, Forslund-Startceva SK, Bahring S, Bartolomaeus H, Siebert N. Machine learning identifies microbiome and clinical predictors of sustained weight loss following prolonged fasting. Genome Med. 2026 Sep 16;18(1):136. doi: 10.1186/s13073-026-01765-0.
- Individual participant dataSharing planned: Yes. Individual participant data that underlie the results of reported articles (text, tables, figures, supplemental data) will be shared after deidentification.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Sylvia Bähring, PhD principal investigator
Charite University, Berlin, Germany
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Buchinger fasting in people with Healthy, run by Charite University, Berlin, Germany 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 11 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 21 Aug 2024. 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. Some participants in this study may receive a placebo. 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?
Resting Energy Expenditure (time frame: 6-th day of fasting compared to baseline). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04452916, which also lists 1 linked publication.
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 21 Aug 2024; AzTrials last refreshed its copy on 27 Oct 2026.