Irritable Bowel SyndromeNCT07829666
Short-Term Effects of Low-FODMAP, NICE Dietary Advice, and Intermittent Fasting in Irritable Bowel Syndrome
A study testing Low-FODMAP Diet, Adapted NICE Dietary Advice and 16:8 Intermittent Fasting in people with Irritable Bowel Syndrome, run by Acibadem University at 1 site in Turkey (Türkiye).
Trial summary
The goal of this clinical trial is to compare the short-term effects of three dietary approaches in adults with irritable bowel syndrome (IBS): a low-FODMAP diet, adapted National Institute for Health and Care Excellence (NICE) dietary advice, and adapted NICE dietary advice combined with 16:8 intermittent fasting. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Irritable Bowel Syndrome
- What is being tested?
- Low-FODMAP Diet, Adapted NICE Dietary Advice and 16:8 Intermittent Fasting
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 90 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Feb 2024to 1 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 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18-65 years Diagnosis of irritable bowel syndrome (IBS) according to the Rome IV criteria IBS subtype classified as IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), or IBS with mixed bowel habits (IBS-M)
Who cannot join
- Celiac disease Inflammatory bowel disease History of cancer Diabetes Kidney disease Pregnancy Current adherence to an elimination diet
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Short-Term Effects of a Low-FODMAP Diet, Adapted NICE Dietary Advice, and Adapted NICE Dietary Advice Combined With Intermittent Fasting on Symptoms and Quality of Life in Irritable Bowel Syndrome: A Three-Arm, Non-Randomized Controlled Dietary Intervention Study
The goal of this clinical trial is to compare the short-term effects of three dietary approaches in adults with irritable bowel syndrome (IBS): a low-FODMAP diet, adapted National Institute for Health and Care Excellence (NICE) dietary advice, and adapted NICE dietary advice combined with 16:8 intermittent fasting.
The main questions this study aims to answer are:
Read more
How do these three dietary approaches affect IBS symptom severity after two weeks? How do these three dietary approaches affect IBS-related quality of life after two weeks? The researchers hypothesize that the low-FODMAP diet will produce the greatest short-term reduction in IBS symptom severity. The study will also explore whether adding 16:8 intermittent fasting to adapted NICE dietary advice provides additional benefit.
Researchers will compare the three dietary groups to determine whether the changes in IBS symptoms and quality of life differ between the dietary approaches.
Participants will:
Follow one of the three dietary approaches for two weeks. Attend study visits at the beginning of the study, after one week, and after two weeks.
Keep records of their food and fluid intake. Complete questionnaires about IBS symptoms, quality of life, anxiety, and depression.
Record their stool form and frequency during the study.
- Conditions
- Irritable Bowel Syndrome
- Being tested
- Low-FODMAP Diet, Adapted NICE Dietary Advice, 16:8 Intermittent Fasting
- Keywords
- Low-FODMAP Diet, NICE Dietary Advice, Intermittent Fasting, 16:8 Intermittent Fasting, Irritable Bowel Syndrome
- Medical subject headings
- Irritable Bowel Syndrome, Intermittent Fasting
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low-FODMAP DietBehavioural
Participants followed a researcher-designed low-FODMAP elimination diet for two weeks. The dietary intervention was delivered by a dietitian who had completed Monash University Low-FODMAP Diet Training. Foods containing fermentable oligosaccharides, lactose, excess fructose, and polyols were restricted. The reintroduction phase of the low-FODMAP diet was not implemented during the two-week study period.
Adapted NICE Dietary AdviceBehavioural
Participants followed adapted NICE dietary advice for two weeks. The recommendations included eating regular meals and avoiding prolonged fasting, drinking at least 2 liters of water per day, limiting
16:8 Intermittent FastingBehavioural
Participants followed a 16:8 intermittent fasting regimen in addition to adapted NICE dietary advice for two weeks. All meals were consumed within an 8-hour eating window, either from 11:00 to 19:00 or from 12:00 to 20:00, followed by a 16-hour fasting period. One or two snacks were permitted within the eating window. No specific restriction on fiber or FODMAP intake was applied.
| Study group | Role | What they receive |
|---|---|---|
| Low-FODMAP Diet (LF) | Experimental | Participants in this arm followed a researcher-designed low-FODMAP elimination diet for two weeks. The dietary intervention was delivered by a dietitian who had completed Monash University Low-FODMAP Diet Training. Receives: Behavioral: Low-FODMAP Diet |
| Adapted NICE Dietary Advice (NICE) | Active comparator | Participants in this arm followed adapted NICE dietary advice for two weeks. The recommendations included eating regular meals and avoiding prolonged fasting, drinking at least 2 liters of water per day, limiting fruit intake to a maximum of three servings (240 g) per day, limiting tea and coffee to a maximum of three cups per day, and limiting alcohol and carbonated beverages. No specific restriction on fiber or FODMAP intake was applied. Receives: Behavioral: Adapted NICE Dietary Advice |
| Adapted NICE Dietary Advice Plus Intermittent Fasting (NICE-IF) | Active comparator | Participants in this arm followed adapted NICE dietary advice combined with a 16:8 intermittent fasting regimen for two weeks. All meals were consumed within an 8-hour eating window, either from 11:00 to 19:00 or from 12:00 to 20:00, followed by a 16-hour fasting period. One or two snacks were permitted within the eating window. No specific restriction on fiber or FODMAP intake was applied. Receives: Behavioral: 16:8 Intermittent Fasting |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Irritable Bowel Syndrome Symptom Severity
IBS symptom severity was assessed using the Irritable Bowel Syndrome Severity Scoring System (IBS-SSS). The total score ranges from 0 to 500, with higher scores indicating greater symptom severity. A reduction of at least 50 points was considered a clinically meaningful improvement.
Measured: Baseline to 2 weeks
Secondary outcomes (1)
Change in Irritable Bowel Syndrome-Specific Quality of Life
IBS-specific quality of life was assessed using the Irritable Bowel Syndrome Quality of Life questionnaire (IBS-QOL). The questionnaire consists of 34 items across eight subscales. Scores are transformed to a 0-100 scale, with higher scores indicating better IBS-specific quality of life.
Measured: Baseline to 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Sep 2026
- Study start1 Feb 2024
- Primary completion1 Nov 2024
- Study completion1 Nov 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel SyndromeStudies of the same condition, open and under way.
- More trials run by Acibadem UniversityThe 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
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 90 participants (actual)
Sponsor and investigators
- Lead sponsor
- Acibadem University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Nur E Baydı Ozman, PhD, Principal investigator, Acibadem Atasehir Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07829666
- Sponsor's protocol ID
- 2023-16/560
- Status last verified
- Sep 2026
- First submitted
- 15 Sep 2026
- Last updated
- 21 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Short-Term Effects of a Low-FODMAP Diet, Adapted NICE Dietary Advice, and Adapted NICE Dietary Advice Combined With Intermittent Fasting on Symptoms and Quality of Life in Irritable Bowel Syndrome: A Three-Arm, Non-Randomized Controlled Dietary Intervention Study
- ClinicalTrials.gov ID
- NCT07829666
- Acronym / sponsor ID
- 2023-16/560
- Conditions
- Irritable Bowel Syndrome
- Keywords
- Low-FODMAP Diet, NICE Dietary Advice, Intermittent Fasting, 16:8 Intermittent Fasting, Irritable Bowel Syndrome
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 90 participants (actual)
- Lead sponsor
- Acibadem UniversityUniversity, hospital or other
- Study start
- 1 Feb 2024 (actual)
- Primary completion
- 1 Nov 2024 (actual)
- Study completion
- 1 Nov 2024 (actual)
- First posted
- 21 Sep 2026 (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.
The goal of this clinical trial is to compare the short-term effects of three dietary approaches in adults with irritable bowel syndrome (IBS): a low-FODMAP diet, adapted National Institute for Health and Care Excellence (NICE) dietary advice, and adapted NICE dietary advice combined with 16:8 intermittent fasting.
The main questions this study aims to answer are:
How do these three dietary approaches affect IBS symptom severity after two weeks? How do these three dietary approaches affect IBS-related quality of life after two weeks? The researchers hypothesize that the low-FODMAP diet will produce the greatest short-term reduction in IBS symptom severity. The study will also explore whether adding 16:8 intermittent fasting to adapted NICE dietary advice provides additional benefit.
Researchers will compare the three dietary groups to determine whether the changes in IBS symptoms and quality of life differ between the dietary approaches.
Participants will:
Follow one of the three dietary approaches for two weeks. Attend study visits at the beginning of the study, after one week, and after two weeks.
Keep records of their food and fluid intake. Complete questionnaires about IBS symptoms, quality of life, anxiety, and depression.
Record their stool form and frequency during the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Low-FODMAP Diet (LF) | Experimental | Behavioral: Low-FODMAP DietParticipants in this arm followed a researcher-designed low-FODMAP elimination diet for two weeks. The dietary intervention was delivered by a dietitian who had completed Monash University Low-FODMAP Diet Training. |
| Adapted NICE Dietary Advice (NICE) | Active comparator | Behavioral: Adapted NICE Dietary AdviceParticipants in this arm followed adapted NICE dietary advice for two weeks. The recommendations included eating regular meals and avoiding prolonged fasting, drinking at least 2 liters of water per day, limiting fruit intake to a maximum of three servings (240 g) per day, limiting tea and coffee to a maximum of three cups per day, and limiting alcohol and carbonated beverages. No specific restriction on fiber or FODMAP intake was applied. |
| Adapted NICE Dietary Advice Plus Intermittent Fasting (NICE-IF) | Active comparator | Behavioral: 16:8 Intermittent FastingParticipants in this arm followed adapted NICE dietary advice combined with a 16:8 intermittent fasting regimen for two weeks. All meals were consumed within an 8-hour eating window, either from 11:00 to 19:00 or from 12:00 to 20:00, followed by a 16-hour fasting period. One or two snacks were permitted within the eating window. No specific restriction on fiber or FODMAP intake was applied. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Adults aged 18-65 years Diagnosis of irritable bowel syndrome (IBS) according to the Rome IV criteria IBS subtype classified as IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), or IBS with mixed bowel habits (IBS-M)
Key exclusion criteria (1 listed)
- Celiac disease Inflammatory bowel disease History of cancer Diabetes Kidney disease Pregnancy Current adherence to an elimination diet
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 |
|---|---|---|
| Low-FODMAP DietParticipants followed a researcher-designed low-FODMAP elimination diet for two weeks. The dietary intervention was delivered by a dietitian who had completed Monash University Low-FODMAP Diet Training. Foods containing fermentable oligosaccharides, lactose, excess fructose, and polyols were restricted. The reintroduction phase of the low-FODMAP diet was not implemented during the two-week study period. | Behavioural | Low-FODMAP Diet (LF) |
| Adapted NICE Dietary AdviceParticipants followed adapted NICE dietary advice for two weeks. The recommendations included eating regular meals and avoiding prolonged fasting, drinking at least 2 liters of water per day, limiting | Behavioural | Adapted NICE Dietary Advice (NICE) |
| 16:8 Intermittent FastingParticipants followed a 16:8 intermittent fasting regimen in addition to adapted NICE dietary advice for two weeks. All meals were consumed within an 8-hour eating window, either from 11:00 to 19:00 or from 12:00 to 20:00, followed by a 16-hour fasting period. One or two snacks were permitted within the eating window. No specific restriction on fiber or FODMAP intake was applied. | Behavioural | Adapted NICE Dietary Advice Plus Intermittent Fasting (NICE-IF) |
Primary outcome
Change in Irritable Bowel Syndrome Symptom Severity
Time frame: Baseline to 2 weeks
IBS symptom severity was assessed using the Irritable Bowel Syndrome Severity Scoring System (IBS-SSS). The total score ranges from 0 to 500, with higher scores indicating greater symptom severity. A reduction of at least 50 points was considered a clinically meaningful improvement.
1 secondary outcome
Change in Irritable Bowel Syndrome-Specific Quality of Life
Time frame: Baseline to 2 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 21 Sep 2026.
- 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.
Nur E Baydı Ozman, PhD principal investigator
Acibadem Atasehir Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low-FODMAP Diet, Adapted NICE Dietary Advice and 16:8 Intermittent Fasting in people with Irritable Bowel Syndrome, run by Acibadem University at 1 site in Turkey (Türkiye).
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 1 inclusion and 1 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 Sep 2026. 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 Turkey (Türkiye). 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?
Change in Irritable Bowel Syndrome Symptom Severity (time frame: Baseline to 2 weeks). 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 21 Sep 2026; AzTrials last refreshed its copy on 7 Nov 2026.