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CompletedNCT05810168Updated May 1, 2026

Traditional Dietary Advice Versus Low FODMAP Diet in Postprandial Functional Dyspepsia

An interventional study of Dietary modifications in Dyspepsia and Functional Gastrointestinal Disorders, sponsored by Sheffield Teaching Hospitals NHS Foundation Trust. Completed at 1 site in United Kingdom. Open to participants aged 18 Years to 60 Years. Per ClinicalTrials.gov, last updated 2026-05-01.

Sponsored by Sheffield Teaching Hospitals NHS Foundation Trust · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
60
Allocation
Randomized
Ages
18 Years to 60 Years
Sex
All
01

Study summary

Functional dyspepsia is common, affecting 7.2% of the global population, and associated with substantial health impairment. Almost 80% of patients with functional dyspepsia report meal-related symptoms and are classified as having the postprandial distress syndrome (PDS) variant. However, studies evaluating dietary modifications in PDS are sparse.

The investigators will perform a randomised trial evaluating traditional dietary advice (TDA) vs. a diet low in fermentable fermentable oligo-, di-, mono- saccharides and polyols (low FODMAP diet) in PDS.

70 patients with PDS will be randomly assigned TDA or a low FODMAP diet. The TDA group will be recommended to eat small, regular meals and reduce the intake of caffeine/alcohol/fizzy drinks, fatty/processed/spicy foods, and fibre. The low FODMAP diet group will be advised to exclude fermentable carbohydrates, which are present in wheat-based products, many fruits/vegetables, pulses, beans, dairy, and sweeteners.

Questionnaires are to be completed during the 6-week trial, including self-reported adequate relief of dyspeptic symptoms, and the validated Leuven Postprandial Distress Scale (LPDS), Gastrointestinal Symptom Rating Scale, and Nepean Dyspepsia Quality of Life Index.

The primary endpoint to define clinical response will be evaluated over weeks 4-6 as >0.5-point reduction in the PDS subscale of the LPDS (calculated as the mean scores for early satiety, postprandial fullness, and upper abdominal bloating).

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Conditions studied

  • Dyspepsia
  • Functional Gastrointestinal Disorders
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In context

Dyspepsia

363 studies on the registry are indexed under Dyspepsia; 51 are open to participants now.

This study's enrollment of 60 is below the median of 87 across 297 interventional studies indexed under Dyspepsia.

Browse Dyspepsia studies →

Lead sponsor

Sheffield Teaching Hospitals NHS Foundation Trust is the lead sponsor of 207 studies on the registry; 26 are open to participants now.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years to 60 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Fulfil Rome IV symptoms criteria for postprandial functional dyspepsia
  • Normal upper gastrointestinal endoscopy within last 3years
  • Online access
  • English literate

Exclusion criteria

Exclusion Criteria:

  • Organic gastrointestinal diseases (e.g. inflammatory bowel disease, GI cancer, coeliac disease)
  • Major abdominal surgery (except laparoscopy, appendectomy, cholecystectomy)
  • Documented H.pylori in the last 3 months
  • History of eating disorders
  • Body mass index \<20
  • Current dietary interventions
  • Current use of opioids or anti-inflammatory drugs
  • Severe systemic disease (e.g. cardiac, renal, respiratory) necessitating frequent medical consultations)
  • Pregnant
  • Diabetes mellitus
  • Scleroderma
  • Memory impairment
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Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
60 participants (actual)

Study arms

  • Active comparator
    Traditional Dietary Advice

    Recommended to eat smaller, regular meals and reduce the intake of caffeine/alcohol/fizzy drinks, fatty/processed/spicy foods, and fibre

    Other: Dietary modifications

  • Active comparator
    Low FODMAP diet

    FODMAPs are fermentable carbohydrates that increase intestinal water and gas production that, in those with visceral hypersensitivity, induces gastrointestinal symptoms. The low FODMAP diet therefore excludes fermentable carbohydrates, which are present in wheat-based products, many fruits/vegetables, pulses, beans, dairy, and sweeteners.

    Other: Dietary modifications

Interventions

  • OtherDietary modifications

    TDA and low FODMAP diet

06

What researchers measure

Primary outcomes

  1. Proportion of clinical responders between traditional dietary advice vs. a Low FODMAP diet on the leuven postprandial distress scale (LPDS)

    The Leuven Postprandial Distress Scale (LPDS) assesses the severity of 8 upper gastrointestinal symptoms scored from 0 (none) to 4 (very severe). A difference of 0.5 from baseline for the cardinal PDS symptoms (average of first 3 questions) will be used as a cut-off to determine clinical response by comparing average pre-treatment scores with the average score during weeks 4-6.

    Time frame: 6 weeks

Secondary outcomes

  1. Proportion of clinical responders between traditional dietary advice vs. a low FODMAP diet

    Self-reported adequate relief of dyspeptic symptoms as a binary answer (yes or no). A responder will be defined if ≥50% adequate relief of dyspeptic symptoms during weeks 4-6

    Time frame: 6 weeks

  2. Changes in Gastrointestinal Symptom Rating Irritable Bowel syndrome Scale

    The validated Gastrointestinal Symptom Rating Scale assesses the symptoms of irritable bowel syndrome, depicting problems with satiety, abdominal pain, diarrhoea, constipation and bloating. Higher scores represent greater symptom severity. Change in scores will be compared within- and between- groups.

    Time frame: 6 weeks

  3. Changes in Napean Dyspepsia-related Quality of Life Index

    The Napean Dyspepsia Scale is a validated questionnaire assessing dyspepsia-related quality of life syndrome, with higher scores representing worse quality of life. Change in scores will be compared within- and between- groups

    Time frame: 6 weeks

  4. Changes in Hospital Anxiety and Depression scale

    The Hospital Anxiety and Depression Scale is a validated questionnaire assessing mood, with higher scores representing worse mood. Change in scores will be compared within- and between- groups

    Time frame: 6 weeks

  5. Changes in Somatic Symptom reporting

    The validated patient health questionnaire-12 assess extra-intestinal somatic symptoms, with higher scores representing greater somatic symptom severity. Change in scores will be compared within- and between- groups

    Time frame: 6 weeks

  6. Changes in nutritional intake

    The Comprehensive Nutritional Assessment Questionnaire assesses macronutrient and micronutrient intake, FODMAPs, fibre, starch, glycaemic index/load. Change in scores will be compared within- and between- groups

    Time frame: 6 weeks

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Study locations

1 site
  • Royal Hallamshire Hospital
    Sheffield, South Yorkshire S10 2JF, United Kingdom
08

References and documents

Publications

  • Shiha MG, Buckle RL, Shaw CC, Aziz I. Low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols Diet vs Traditional Dietary Advice in Postprandial Functional Dyspepsia: A Randomized Clinical Trial. Clin Gastroenterol Hepatol. 2026 Jun 15:S1542-3565(26)00440-4. doi: 10.1016/j.cgh.2026.06.006. Online ahead of print. PubMed 42297316 ↗

Individual participant data

Plan to share: No

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 1, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT05810168
Lead sponsor
Sheffield Teaching Hospitals NHS Foundation Trust
Responsible party
Sponsor
First posted
Apr 12, 2023
Start date
Aug 30, 2023
Primary completion
Oct 31, 2025
Completion
Oct 31, 2025
Last update
May 1, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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