Intermittent FastingLIMITFOODNCT04732130
Monitoring During Different Intermittent Fasting Protocols in Non-Obese Adults
A study testing Time-Restricted Feeding and Alternate Day Fasting in people with Intermittent Fasting and Overweight, run by Philipp Gerber at 1 site in Switzerland.
Trial summary
LIMITFOOD is a randomized clinical intervention study that investigates the effects of two different intermittent fasting protocols compared to a control group on the health of normal- and overweight adults. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Intermittent Fasting, Overweight, Time Restricted Feeding
- What is being tested?
- Time-Restricted Feeding and Alternate Day Fasting
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 76 participants
- Where
- 1 siteSwitzerland
- Study dates
- 10 Mar 2021to 1 Jul 2023
- 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
- Age between 18-40 years, both inclusive
- Non-obese, BMI between 23 and 30 kg/m2, both inclusive
- Non-smoker
- Good knowledge of German or English language
- Stable weight change (change < +/- 10% current bodyweight) for 3 months prior to the study
- Glycohemoglobin (HbA1c) < 5.7% without glucose lowering medication
- LDL-cholesterol < 180 mg/dl without lipid lowering medication
- Blood pressure < 140/90 mmHG without blood pressure lowering medication
Who cannot join
- Subjects who have a fasting period of > 12h per day on a regular basis and do not eat at least three main meals per day.
- Current habitual use of dietary supplements (e.g. vitamins, minerals) and/or unwillingness to cease intake of dietary supplements.
- Antibiotics intake during 3 months prior to the study
- Food intolerances, allergies and sensitivities (e.g. lactose/gluten intolerance, food allergies) or dietary restrictions (e.g. vegan lifestyle)
- Acute or chronic infections, malignant disease, renal, hepatic (more than two-fold increased transaminases), pulmonary, neurological (epilepsy) or psychiatric diseases, manifested atherosclerosis, or any other disease precluding participation in the study.
- Diabetes
Show all 15Show fewer
- Known alcohol, substance or drug abuse, concomitant medication
- More than four hours of physical exercise per week
- Women who are pregnant, breast-feeding or aiming to become pregnant during course of the trial
- Women and men on hormonal supplementation
- Women with a very irregular menstrual cycle
- Therapy with antidepressants within the past 6 months
- Regular therapy with acetylsalicyclic acid or current medication to regulate blood sugar, blood pressure or lipids
- Subjects likely to fail to comply with the study protocol
- Subjects who do not give informed consent
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
Department of Endocrinology, Diabetology and Clinical Nutrition
Zurich, 8091
About this study
Official title: Longitudinal Monitoring During Different Intermittent Fasting Protocols in Non-Obese Adults - A Randomized Clinical Trial
LIMITFOOD is a randomized clinical intervention study that investigates the effects of two different intermittent fasting protocols compared to a control group on the health of normal- and overweight adults. A total of 72 participants will be randomized into three equally sized groups: an alternate day fasting, a time-restricted feeding and a control group.
Read the detailed description
The prevalence of overweight has risen considerably all over the world in the past century. Epidemiological studies have shown that, starting from a body mass index of 20-21 kg/m2, increasing BMI levels are associated with progressively increased risks of developing diabetes, cardiovascular disease, several types of cancer and other diseases. The problem is pronounced by the unlimited and constant availability of food. Treatment of overweight is still difficult and finding effective and more personalized strategies to manage these conditions is crucial.
Intermittent fasting has been suggested as an alternative way to address these problems. Intermittent fasting is an eating pattern that involves rotating periods of eating and fasting. Animal studies and previous human clinical trials have provided evidence that various types of intermittent fasting lead to weight loss and improved health markers not only in obese, but also in healthy, non-obese adults.There are several types of intermittent fasting. The most popular version is time-restricted feeding (TRF), which allows ad libitum (at one's pleasure) energy intake within a defined period of time each day (6-12h). Another subtype of IF is called alternate day fasting (ADF). ADF is defined as 'feast days' on which food is consumed ad libitum, which alternate with 'fast days' on which food is withheld or reduced.
However, despite the growing popularity of intermittent fasting, it is not clear which type of IF is most effective and what fasting window is needed to induce beneficial effects. Additionally, tools to longitudinally track personal progress of dieting are lacking. Therefore, the main objective of this study is to compare the effects of each of two different intermittent fasting protocols (TRF and ADF) on metabolic parameters to a control group. Furthermore, a new dynamic measurement technique, using breath analysis, will allow to better monitor the progress of individual participants.
- Conditions
- Intermittent Fasting, Overweight, Time Restricted Feeding
- Being tested
- Time-Restricted Feeding, Alternate Day Fasting
- Medical subject headings
- Intermittent Fasting, Overweight
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Time-Restricted FeedingBehavioural
Participants are instructed to limit food intake to maximum 8 hours per day.
Alternate Day FastingBehavioural
Participants are instructed to fast every other day.
| Study group | Role | What they receive |
|---|---|---|
| Time-Restricted Feeding | Active comparator | Participants in the time-restricted feeding are instructed to eat ad libitum from 12:00 to 20:00 daily, and fast from 20:00 to 12:00 daily for 4 weeks. Receives: Behavioral: Time-Restricted Feeding |
| Alternate Day Fasting | Active comparator | Participants in the alternate day fasting group are instructed to eat every second day ad libitum, but to abstain from calorie intake on fast days (100 % restriction) for 4 weeks. Receives: Behavioral: Alternate Day Fasting |
| Control | No intervention | Participants in the control group are instructed to maintain their habitual diet regimen. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fat mass
Change in whole body fat mass
Measured: 4 weeks
Secondary outcomes (3)
Continuous glucose monitoring (CGM)
During the study period the CGM system will measure the continuous glucose concentration of the participants and thereby any changes will be measured.
Measured: 4 weeks
Physical activity energy expenditure
Change in mean physical activity energy expenditure will be recorded using an Actiheart monitor during the intervention.
Measured: 4 weeks
Resting metabolic rate (measured by indirect calorimetry)
Change in resting metabolic rate
Measured: 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Feb 2021
- Study start10 Mar 2021
- Primary completion1 Jul 2023
- Study completion1 Jul 2023
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 Intermittent FastingStudies of the same condition, open and under way.
- 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 76 participants (actual)
Sponsor and investigators
- Lead sponsor
- Philipp Gerber
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Philipp Gerber, University of Zurich
- Investigators
- Philipp Gerber, MD, Principal investigator, University of Zurich
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04732130
- Sponsor's protocol ID
- LIMITFOOD
- Acronym
- LIMITFOOD
- Status last verified
- Oct 2023
- First submitted
- 19 Jan 2021
- Last updated
- 6 Oct 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Derron N, Guntner AT, Weber IC, Braun J, Koska IO, Othman A, Monch L, von Eckardstein A, Puhan MA, Beuschlein F, Hochuli M, Zamboni N, Guggenberger R, Gerber PA. Alternate-day fasting elicits larger changes in fat mass than time-restricted eating in adults without obesity - A randomized clinical trial. Clin Nutr. 2025 Oct;53:212-221. doi: 10.1016/j.clnu.2025.08.033. Epub 2025 Sep 3.
PubMed 40945487
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Longitudinal Monitoring During Different Intermittent Fasting Protocols in Non-Obese Adults - A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT04732130
- Acronym / sponsor ID
- LIMITFOOD / LIMITFOOD
- Conditions
- Intermittent Fasting, Overweight, Time Restricted Feeding
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 76 participants (actual)
- Lead sponsor
- Philipp GerberUniversity, hospital or other
- Study start
- 10 Mar 2021 (actual)
- Primary completion
- 1 Jul 2023 (actual)
- Study completion
- 1 Jul 2023 (actual)
- First posted
- 1 Feb 2021 (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.
LIMITFOOD is a randomized clinical intervention study that investigates the effects of two different intermittent fasting protocols compared to a control group on the health of normal- and overweight adults. A total of 72 participants will be randomized into three equally sized groups: an alternate day fasting, a time-restricted feeding and a control group.
Detailed description
The prevalence of overweight has risen considerably all over the world in the past century. Epidemiological studies have shown that, starting from a body mass index of 20-21 kg/m2, increasing BMI levels are associated with progressively increased risks of developing diabetes, cardiovascular disease, several types of cancer and other diseases. The problem is pronounced by the unlimited and constant availability of food. Treatment of overweight is still difficult and finding effective and more personalized strategies to manage these conditions is crucial.
Intermittent fasting has been suggested as an alternative way to address these problems. Intermittent fasting is an eating pattern that involves rotating periods of eating and fasting. Animal studies and previous human clinical trials have provided evidence that various types of intermittent fasting lead to weight loss and improved health markers not only in obese, but also in healthy, non-obese adults.There are several types of intermittent fasting. The most popular version is time-restricted feeding (TRF), which allows ad libitum (at one's pleasure) energy intake within a defined period of time each day (6-12h). Another subtype of IF is called alternate day fasting (ADF). ADF is defined as 'feast days' on which food is consumed ad libitum, which alternate with 'fast days' on which food is withheld or reduced.
However, despite the growing popularity of intermittent fasting, it is not clear which type of IF is most effective and what fasting window is needed to induce beneficial effects. Additionally, tools to longitudinally track personal progress of dieting are lacking. Therefore, the main objective of this study is to compare the effects of each of two different intermittent fasting protocols (TRF and ADF) on metabolic parameters to a control group. Furthermore, a new dynamic measurement technique, using breath analysis, will allow to better monitor the progress of individual participants.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Time-Restricted Feeding | Active comparator | Behavioral: Time-Restricted FeedingParticipants in the time-restricted feeding are instructed to eat ad libitum from 12:00 to 20:00 daily, and fast from 20:00 to 12:00 daily for 4 weeks. |
| Alternate Day Fasting | Active comparator | Behavioral: Alternate Day FastingParticipants in the alternate day fasting group are instructed to eat every second day ad libitum, but to abstain from calorie intake on fast days (100 % restriction) for 4 weeks. |
| Control | No intervention | –Participants in the control group are instructed to maintain their habitual diet regimen. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Age between 18-40 years, both inclusive
- Non-obese, BMI between 23 and 30 kg/m2, both inclusive
- Non-smoker
- Good knowledge of German or English language
- Stable weight change (change < +/- 10% current bodyweight) for 3 months prior to the study
Key exclusion criteria (15 listed)
- Subjects who have a fasting period of > 12h per day on a regular basis and do not eat at least three main meals per day.
- Current habitual use of dietary supplements (e.g. vitamins, minerals) and/or unwillingness to cease intake of dietary supplements.
- Antibiotics intake during 3 months prior to the study
- Food intolerances, allergies and sensitivities (e.g. lactose/gluten intolerance, food allergies) or dietary restrictions (e.g. vegan lifestyle)
- Acute or chronic infections, malignant disease, renal, hepatic (more than two-fold increased transaminases), pulmonary, neurological (epilepsy) or psychiatric diseases, manifested atherosclerosis, or any other disease precluding participation in the study.
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 |
|---|---|---|
| Time-Restricted FeedingParticipants are instructed to limit food intake to maximum 8 hours per day. | Behavioural | Time-Restricted Feeding |
| Alternate Day FastingParticipants are instructed to fast every other day. | Behavioural | Alternate Day Fasting |
Primary outcome
Fat mass
Time frame: 4 weeks
Change in whole body fat mass
3 secondary outcomes
Continuous glucose monitoring (CGM)
Time frame: 4 weeks
Physical activity energy expenditure
Time frame: 4 weeks
Resting metabolic rate (measured by indirect calorimetry)
Time frame: 4 weeks
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 6 Oct 2023.
- Derived from this study: PubMed 40945487Derron N, Guntner AT, Weber IC, Braun J, Koska IO, Othman A, Monch L, von Eckardstein A, Puhan MA, Beuschlein F, Hochuli M, Zamboni N, Guggenberger R, Gerber PA. Alternate-day fasting elicits larger changes in fat mass than time-restricted eating in adults without obesity - A randomized clinical trial. Clin Nutr. 2025 Oct;53:212-221. doi: 10.1016/j.clnu.2025.08.033. Epub 2025 Sep 3.
- Individual participant dataSharing planned: No
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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.
Philipp Gerber, MD principal investigator
University of Zurich
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Time-Restricted Feeding and Alternate Day Fasting in people with Intermittent Fasting and Overweight, run by Philipp Gerber at 1 site in Switzerland.
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 8 inclusion and 15 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 6 Oct 2023. 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 Switzerland. 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?
Fat mass (time frame: 4 weeks). 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 NCT04732130, 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 6 Oct 2023.