Comparing fat-free and balanced diets for gallstone disease management

Rationale Diet for Gallstone Disease (RADIGAL Trial): A Randomized Controlled Trial Comparing Fat-free Versus Balanced (WHO) Diet in Gallstone Disease

Not applicable Interventional University Hospital of Crete · NCT06405906

This study is testing whether a fat-free diet or a balanced diet can help improve the quality of life for people with gallstone disease.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment242 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity Hospital of Crete Academic / other
Locations1 site (Heraklion)
Trial IDNCT06405906 on ClinicalTrials.gov

What this trial studies

This trial aims to evaluate the impact of a fat-free diet versus a balanced WHO diet on the quality of life in patients with gallstone disease. It focuses on symptomatic patients presenting with biliary colic or acute cholecystitis, assessing patient-reported outcomes through a validated questionnaire. The study will analyze differences in quality of life scores at three months and monitor adherence to the diet and occurrence of disease-related symptoms. The trial is divided into two groups based on treatment approach: non-operative management and post-cholecystectomy care.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with symptomatic gallstone disease, specifically those experiencing biliary colic or acute cholecystitis.

Not a fit: Patients with gastrointestinal diseases that affect diet, food allergies, or those unwilling to adhere to the recommended diets may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide evidence for dietary recommendations that improve quality of life for patients with gallstone disease.

How similar studies have performed: While dietary interventions in gallstone disease have been explored, this specific comparison of fat-free versus balanced diets is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria (RADIGAL1):

* 18 years old or older
* presenting with biliary colic in the ED or outpatient clinic, with the surgical team deciding to proceed with non-operative treatment (Group 1)
* presenting with acute calculous cholecystitis in the ED, with the surgical team deciding to proceed with non-operative management (Group 2)

Exclusion Criteria (RADIGAL1):

* history of gastrointestinal disease which might affect diet, e.g., inflammatory bowel disease, irritable bowel syndrome, short bowel syndrome
* inability to provide informed consent
* unwillingness to adhere to the recommended diet
* food allergies or intolerances that would prevent following the diet
* dietary habits (e.g., vegetarians, vegans) that preclude adherence to the recommended diet
* gallstone related cholangitis without biliary colic or cholecystitis
* complications from acute pancreatitis, such as pseudocysts, walled off necrosis, among others

Inclusion Criteria (RADIGAL2):

* 18 years old or older
* undergoing uncomplicated cholecystectomy (open or laparoscopic without bile duct exploration) due to a history of biliary colic (Group 1)
* undergoing uncomplicated cholecystectomy (open or laparoscopic without bile duct exploration) due to acute cholecystitis (Group 2)

Exclusion Criteria (RADIGAL2):

* history of gastrointestinal disease which might affect diet, e.g., inflammatory bowel disease, irritable bowel syndrome, short bowel syndrome
* inability to provide informed consent
* unwillingness to adhere to the recommended diet
* food allergies or intolerances that would prevent following the diet - dietary habits (e.g., vegetarians, vegans) that preclude adherence to the recommended diet
* gallstone related cholangitis without biliary colic or cholecystitis
* complications from acute pancreatitis, such as pseudocysts, walled off necrosis, among others
* choledocholithiasis
* complicated cholecystectomy
* patients undergoing subtotal cholecystectomy
* whether primary operation differs from cholecystectomy (e.g., colectomy)
* patients having treated with percutaneous cholecystostomy

Where this trial is running

Heraklion

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Gallstone DiseaseGallstoneColicCholecystitis, AcuteCholelithiasesPostcholecystectomy SyndromeDietary Habitsgallstone disease
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.