An interventional study of Long-term fasting according to the Buchinger Wilhelmi fasting program in Fasting, sponsored by Buchinger Wilhelmi Development & Holding GmbH. Completed at 1 site in Germany. Open to participants aged 20 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-02-08.
Sponsored by Buchinger Wilhelmi Development & Holding GmbH · Not applicable, Interventional, and Other
The aim of this trial is to investigate the effects of long-term fasting on size, mass, composition and function of metabolic active tissues in several organs that reexpand possibly rejuvenated after 1-4 months. Additionally, the lipid metabolism is investigated in depth.
Fasting displays numerous positive effects on metabolism, health and aging. Surprisingly, few considerations are given to long-term fasting periods.
The metabolic switch from food-derived glucose to adipose tissue-derived fatty acids and ketones as primary cellular fuel is the key to fasting metabolism. Fasting has been shown to improve cardiovascular risk factors and gut microbiota in humans. It provokes profound changes in lipid metabolism. However, many questions are still open concerning the mobilization, exchange, and function of lipids during long-term fasting. Furthermore, recent results show the ability of periodic restrictive nutritional strategies to trigger organ regeneration. This promising regenerative power has not been investigated comprehensively in humans. In addition, the knowledge about the role of human faecal microbiota in health and disease is increasing. Only little is known about its composition and function during fasting. We found indications that the gut microbiome could influence energy metabolism and consequently could influence the dynamic of the metabolic switch.
Long-term fasting under medical supervision according to the Buchinger Wilhelmi fasting program has been demonstrated to be safe and well-tolerated.
The current project investigates the effects of a 9±3 days fasting period by a multi-systemic approach focusing on lipid metabolism and the gut microbiome in 100 subjects. Additionally, the body composition in combination with muscle performance will be analyzed in-depth in a subgroup of 32 subjects.
392 studies on the registry are indexed under Fasting; 63 are open to participants now.
This study's enrollment of 62 is above the median of 45 across 311 interventional studies indexed under Fasting.
Browse Fasting studies →Buchinger Wilhelmi Development & Holding GmbH is the lead sponsor of 5 studies on the registry; 2 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The participants will undergo 6-12 fasting days according to the Buchinger Wilhelmi fasting program
Other: Long-term fasting according to the Buchinger Wilhelmi fasting program
the participants will undergo a fasting program that includes the daily intake of 250 kcal under medical supervision
Changes in whole body composition
Fat mass, lean mass, water content measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in the composition of the heart
Fat mass, lean mass, water content measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in the composition of the liver
Fat mass, lean mass, water content measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in the composition of the kidney
Fat mass, lean mass, water content measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in the composition of the spleen
Fat mass, lean mass, water content measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in the composition of the quadriceps
Fat mass, lean mass, water content measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in the composition of the adipose tissue
Fat mass, lean mass, water content measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in HDL cholesterol efflux capacity
measured in serum by a standardized used radioisotopic technique
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in serum cholesterol loading capacity
measured in serum using radioactive cholesterol loaded macrophages
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in HS-Omega-3 Index
Determination of fatty acid (C 14:0; 16:0; 18:0; 20:0; 22:0; 24:0; 16:1 n-7; 18:1 n-9; 20:1 n-9; 24:1 n-9; 18:2 n-6; 18: 3 n-6; 20: 3 n-6; 22:2 n-6; 20:4 n-6; 22:4 n-6; 22:5 n-6; 18: 3 n-3; 20:5 n-3; 22:5 n-3; 22:6 n-3; 16:1 n-7t; 18:1 n-9t; 18:2 n-6tt; 18:2 n-6ct; 18:2 n-6tc) in erythrocyte membranes with highly standardized analytical procedure
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in faecal microbiota composition and function (carbohydrate metabolism)
Shotgun metagenomics, 5Gb of DNA sequencing data.
Time frame: Baseline and changes after an average of 10 (+/-3) fasting days
Changes in metabolome
using an untargeted metabolomics approach to investigate changes in the metabolome, with a focus on the polyamine biosynthetic pathway at the cellular level in PBMCs and compare them with changes in the circulating plasma/serum metabolome
Time frame: Baseline and changes after 3 fasting days, the end of fasting as well as one and four months afterwards
Changes in hydrogen sulfide production capacity
measured in serum and urine using the lead acetate assay
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in brain morphometry
measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in cardiac mass
measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in lower limbs (quadriceps, hamstrings, calves)
measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in lumbosacral muscle mass
measured by magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in systolic cardiac function
global and regional function (right and left ejection fraction, right and left end-diastolic and end-systolic volumes, peak regional strains (circumferential, longitudinal strain) measured with magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in diastolic cardiac function
global and regional diastolic function (peak filling rate, torsion rate, diastolic strain rate) measured with magnetic resonance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in apparent diffusion coefficient (ADC)
measured with magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in fiber strain (Eff)
measured with magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in fractional anisotropy (FA)
measured with magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in helix angle (HA)
measured with magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in mean diffusivity (MD)
measured with magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in cardiovascular fitness
using the maximal oxygen consumption (VO2max)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in muscle metabolism and mitochondrial oxidative capacity: TauPCr(s)
during ergometric effort in MRI at the level of the sural muscle (31P spectroscopy)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in muscle metabolism and mitochondrial oxidative capacity: PCr hydrolysis (%)
during ergometric effort in MRI at the level of the sural muscle (31P spectroscopy)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in muscle metabolism and mitochondrial oxidative capacity: PCr concentration
during ergometric effort in MRI at the level of the sural muscle (31P spectroscopy)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in muscle metabolism and mitochondrial oxidative capacity: Pi concentration
during ergometric effort in MRI at the level of the sural muscle (31P spectroscopy)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in muscle metabolism and mitochondrial oxidative capacity: ATP concentration
during ergometric effort in MRI at the level of the sural muscle (31P spectroscopy)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in muscle metabolism and mitochondrial oxidative capacity: pH at rest and post exercise in mM
during ergometric effort in MRI at the level of the sural muscle (31P spectroscopy)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in muscle metabolism and mitochondrial oxidative capacity: T1 of metabolites at rest
during ergometric effort in MRI at the level of the sural muscle (31P spectroscopy)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in muscle metabolism and mitochondrial oxidative capacity: PCr consumption
during ergometric effort in MRI at the level of the sural muscle (31P spectroscopy)
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in multiparametric muscle quantification: T2
measured with quantitative magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in multiparametric muscle quantification: T2 * relaxation time
measured with quantitative magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in multiparametric muscle quantification: susceptibility (chi)
measured with quantitative magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in multiparametric muscle quantification: fat fraction (PDFF)
measured with quantitative magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in quadricipital maximum voluntary contraction
measured with magnetic impedance imaging
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in DNA methylation
biomarker of biological aging using erythrocytes
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in serum amyloid A levels
determined in serum
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in paraoxonase (PON-1) activity
determined in serum
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in lipoprotein transfer enzymes
CETP activity, determined as U/ml using a commercially available assay
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in GlycA
determined in serum
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in proprotein convertase subtilisin/kexin type 9 (PCSK9)
determined in serum by ELISA
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in chylomicrons
determined in serum
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in oxidized phospholipids
determined in serum
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in enzymes
immunoblotting of relevantly altered enzymes in PBMCs
Time frame: Baseline and changes after 3 fasting days, the end of fasting as well as one and four months afterwards
Changes in persulfidation
persulfidation in serum and urine
Time frame: Baseline, and changes after 3 fasting days, at the end of fasting as well as one and four months afterwards
Changes in sulfur compounds
amino acids (using a targeted approach), thiosulfate (measured using the monobromobimane method using HPLC and LC-MS/MS), cysteine and cystine (use the S-sulfocysteine (SSC) method which is a HPLC-based method using automated precolumn derivatization with OPA and UV detection at 338 nm) in serum and urine
Time frame: Baseline and changes after 3 fasting days, at the end of fasting as well as one and four months afterwards
Changes in thiosulfate levels
measured using the monobromobimane method using HPLC and LC-MS/MS
Time frame: Baseline and changes after 3 fasting days, at the end of fasting as well as one and four months afterwards
Changes in cysteine and cystine levels
using the S-sulfocysteine (SSC) method which is a HPLC-based method using automated precolumn derivatization with OPA and UV detection at 338 nm in serum and urine
Time frame: Baseline and changes after 3 fasting days, at the end of fasting as well as one and four months afterwards
Changes in amino acids
using a targeted approach in serum and urine
Time frame: Baseline and changes after 3 fasting days, at the end of fasting as well as one and four months afterwards
Changes in body weight
in kg
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in body mass index
in kg/m²
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in abdominal circumference
in cm
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in resting systolic blood pressure
in mmHg
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in resting diastolic blood pressure
in mmHg
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in resting heart frequency
in beats/min
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in bio-electrical multifrequency impedance analysis
Global and segmental body composition (water, fat and lean mass), liquid distribution (total, extracellular and intracellular water), metabolic indexes (metabolic activity index (MAI), protein content (total and active cell mass fraction) as determined by bioimpedance analysis
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in liver stiffness
measured by FibroScan
Time frame: Baseline, during and after fasting
Changes in physical activity
intensity, duration, frequency measured by triaxial actigraphy
Time frame: Before, daily during fasting as well as one and four months afterwards
Changes in circadian rhythm and sleep
measured by triaxial actigraphy
Time frame: Before, daily during fasting as well as one and four months afterwards
Changes in mental well-being
questionnaires: Warwick-Edinburgh Mental Well-Being Scale
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in global health
questionnaires: PROMIS Scale
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in physical activity
questionnaires: Godin Leisure-Time Exercise Questionnaire
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in sleep quality
questionnaires: Pittsburgh Sleep Quality Index
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in ketonuria
Ketone bodies in urine measured by urine dip sticks
Time frame: during the fasting period and food reintroduction
Changes in ketonemia
Ketone bodies in capillary blood
Time frame: during the fasting period and food reintroduction
Changes in glycemia
Glucose in capillary blood
Time frame: during the fasting period and food reintroduction
Changes in dietary behaviour
questionnaire: short healthy eating index survey
Time frame: Baseline and after fasting as well as one and four months afterwards
Changes in smoking behaviour
questionnaire
Time frame: Baseline and after fasting as well as one and four months afterwards
Changes in alcohol consumption
questionnaire
Time frame: Baseline and after fasting as well as one and four months afterwards
Changes in physical activity
in hours/week
Time frame: Baseline and after fasting as well as one and four months afterwards
Changes in energy level
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in emotional well-being
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in physical well-being
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in symptoms: fatigue
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in symptoms: muscle weakness
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in symptoms: back pain
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in symptoms: hunger
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in symptoms: anxiety
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in symptoms: headache
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Changes in symptoms: sleep disturbances
measured by visual scale (0-10)
Time frame: Baseline, daily during fasting and food reintroduction as well as one and four months afterwards
Adverse events
Documentation of side effects
Time frame: through study completion, an average of 4.5 months
Changes in blood count
blood parameters: leucocytes, erythrocytes, haemoglobin, haematocrit, MCV, MCH, MCHC, thrombocytes, bilirubin
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in differential blood count
blood parameters: basophiles, neutrophils, eosinophiles, monocytes, reticulocytes
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in coagulation
blood parameters: INR, PTT in sec
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in liver enzymes
blood parameters: GOT, GPT, GGT, AP in U/l
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in kidney parameters
blood parameters: uric acid, urea, creatinine in mg/dl
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in inflammatory parameters
blood parameters: hs-CRP, ESR in mm/h, inflammasome, cortisol in µg/dl
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in glucose metabolism
blood parameters: glucose in mmol/l, HbA1c in %, insulin in mU/l
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in lipid parameters
blood parameters: total cholesterol, HDL-C, LDL-C, triglycerides in mmol/l
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in electrolytes
blood parameters: sodium, potassium, calcium, magnesium in mmol/l
Time frame: Baseline and at the end of fasting as well as one and four months afterwards
Changes in the immune response to fasting
using single cell nucleus sequencing
Time frame: Baseline, after 3 fasting days, and at the end of fasting as well as one and four months afterwards
Changes in cell populations (natural killer and T cells)
using single cell nucleus sequencing
Time frame: Baseline, after 3 fasting days, and at the end of fasting as well as one and four months afterwards
Changes in lipoprotein subclasses
determined in serum by high-density ultracentrifugation reflecting cholesterol and triglyceride composition
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in apolipoproteins
ApoA-I and ApoB determined in serum
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in lipoprotein(a)
determined in serum
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Changes in methylation based clocks
biomarker of biological aging using PBMCs
Time frame: Baseline and changes at the end of fasting as well as one and four months afterwards
Sociodemographic Measurements
Age, gender, language, complete family history, current and previous illness and co-morbidities, and current medications
Time frame: Baseline
Changes in nitrogen balance
nitrogen in 24-hours-urine
Time frame: Baseline, daily during fasting as well as food reintroduction
Plan to share: Undecided
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