Development of Gastrointestinal Symptoms in Patients With Anorexia Nervosa and Bulimia Nervosa During Weight Rehabilitation Over Time, Depending on the Nutritional Strategy

NCT07112014 | Recruiting

• 1 other identifier: GastroRehab
• Study Type: observational
• Target: 185
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective observational study investigates the development of gastrointestinal (GI) symptoms in patients with anorexia nervosa (AN) and bulimia nervosa (BN) during multi-week inpatient weight rehabilitation. The study explores how the predominant nutritional strategy-flexitarian, vegetarian, or vegan-relates to changes in GI symptoms over the course of treatment. In addition to diet, the study examines how weight gain and other clinical, psychological, and demographic factors influence the trajectory of GI symptoms. Patients complete weekly questionnaires assessing GI symptoms as part of routine care at the Eating Disorder Center of the Klinik Lüneburger Heide, Germany. Further data are drawn from standard clinical assessments, including body weight, body composition, and psychometric instruments. The primary outcome is the change in GI symptom severity (measured via the GSRS score) from admission to discharge, analyzed in relation to dietary pattern and weight development. Secondary analyses will explore symptom progression over time, group differences between AN and BN, and predictors of GI symptom improvement, including dietary intake, baseline psychological status, symptom change, weight trajectory, and treatment duration. The outcomes will be analyzed separately for AN and BN. The study aims to recruit approximately 150 patients with AN and 35-40 with BN. Inclusion requires a diagnosis of AN (any subtype) or BN, age over 12 years, clinical stability, and the ability to provide informed consent. The findings aim to inform evidence-based dietary recommendations for individuals with eating disorders who experience significant GI symptoms during nutritional rehabilitation.

Conditions

Anorexia Nervosa; Bulimia Nervosa

Keywords

gastrointestinal symptoms; gastrointestinal health; dietary regime; psychological health; vegetarian diet; vegan diet; balanced diet; energy intake

Outcome Measures

Primary Outcomes (1)

• Gastrointestinal Symptoms

  Score of the Gastrointestinal Symptom Rating Scale assessed upon admission and discharge (two time points), in relation to the predominant dietary pattern (\>80% during the rehabilitation phase), defined as flexitarian, vegetarian, or vegan and body weight development. The Gastrointestinal Symptom Rating Scale is a validated questionnaire : Svedlund J, Sjödin I, Dotevall G. GSRS--a clinical rating scale for gastrointestinal symptoms in patients with irritable bowel syndrome and peptic ulcer disease. Dig Dis Sci. (1988) 33(2):129-34. doi: 10.1007/BF01535722. The primary outcome is analyzed seperately for patients with anorexia nervosa and bulimia nervosa.

  Data are collected within the first three days after admission and during the final three days before discharge (two time points).

Secondary Outcomes (21)

• Gastrointestinal Symptoms in the Timecourse

  Data are continuously collected from admission to discharge. Extraction occurs on the first three days of admission, weekly during the stay (on Mondays or Tuesdays, covering the preceding week), and on the final three days of discharge.

• Dietary intake

  Data are continuously collected throughout the inpatient stay. Extraction takes place on the day of admission, weekly during the stay (on Mondays or Tuesdays, reflecting the data of the preceding week), and on the day of discharge.

• Body weight

  Data are continuously collected from admission to discharge. Extraction occurs the second day in the morning after admission, weekly during the stay (on Mondays or Tuesdays), and at the day of discharge

• Body height

  Body weight is measured within the first two days after admission and again within the final two days prior to discharge. For inpatient stays exceeding three months, weight measurements are repeated at three-month intervals.

• Body composition

  Body composition is measured within the first two days after admission and again within the final two days prior to discharge. The outcome is analyzed seperately for patients with anorexia nervosa and bulimia nervosa.

Study Arms (1)

Patients with anorexia nervosa and bulimia nervosa

The study population includes patients with anorexia nervosa (AN) and bulimia nervosa (BN) who participate in an established, multi-week inpatient treatment program aimed at weight rehabilitation and normalization of eating behavior at the Eating Disorder Center of the Klinik Lüneburger Heide in 29549 Bad Bevensen, Germany. The diagnostic and treatment of the patients is as usual. These data, including detailed data on dietary intake, are used for the study. Additionally, information on gastrointestinal sympoms are assessed upon admission and discharge and weekly during the inpatient stay. The outcomes will be analyzed seperately for patients with anorexia nervosa and bulimia nervosa.

Eligibility Criteria

• Age: 12 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients with Anorexia nervosa and Bulimia nervosa. All subtypes will be included.

You may qualify if:

• patients diagnosed with anorexia nervosa (all subtypes)
• patients diagnosed bulimia nervosa

You may not qualify if:

• patients that are medically unable to fill out a short questionnaire on a weekly base.

Sponsors & Collaborators

• University Hospital Tuebingen: lead

Study Sites (1)

Klinik Lüneburger Heide

Bad Bevensen, 29549, Germany

RECRUITING

Related Publications (4)

• Ketel J, Bosch-Bruguera M, Auchter G, Cuntz U, Zipfel S, Enck P, Mack I. Gastrointestinal Microbiota & Symptoms of Depression and Anxiety in Anorexia Nervosa-A Re-Analysis of the MICROBIAN Longitudinal Study. Nutrients. 2024 Mar 19;16(6):891. doi: 10.3390/nu16060891.

  PMID: 38542802 BACKGROUND

• Mack I, Cuntz U, Gramer C, Niedermaier S, Pohl C, Schwiertz A, Zimmermann K, Zipfel S, Enck P, Penders J. Weight gain in anorexia nervosa does not ameliorate the faecal microbiota, branched chain fatty acid profiles, and gastrointestinal complaints. Sci Rep. 2016 May 27;6:26752. doi: 10.1038/srep26752.

  PMID: 27229737 BACKGROUND

• Riedlinger C, Schmidt G, Weiland A, Stengel A, Giel KE, Zipfel S, Enck P, Mack I. Which Symptoms, Complaints and Complications of the Gastrointestinal Tract Occur in Patients With Eating Disorders? A Systematic Review and Quantitative Analysis. Front Psychiatry. 2020 Apr 20;11:195. doi: 10.3389/fpsyt.2020.00195. eCollection 2020.

  PMID: 32425816 BACKGROUND

• Riedlinger C, Mazurak N, Schaffeler N, Stengel A, Giel KE, Zipfel S, Enck P, Mack I. Gastrointestinal complaints in patients with anorexia nervosa in the timecourse of inpatient treatment. Front Psychiatry. 2022 Aug 18;13:962837. doi: 10.3389/fpsyt.2022.962837. eCollection 2022.

  PMID: 36061281 BACKGROUND

MeSH Terms

Conditions

Anorexia Nervosa; Bulimia Nervosa; Psychological Well-Being

Condition Hierarchy (Ancestors)

Feeding and Eating Disorders; Mental Disorders; Personal Satisfaction; Behavior

Study Officials

• Isabelle Mack, Prof.

  University Hospital Tuebingen, Internal Medicine VI, Dept. of Psychosomatic Medicine and Psychotherapy

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Isabelle Mack, Prof. Dr.

CONTACT

+49 070712985614; i.mack@uni-tuebingen.de

Marc Leiteritz, Dr.

CONTACT

m.leiteritz@klinik-lueneburger-heide.de

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 15, 2025
• First Posted: August 8, 2025
• Study Start: September 9, 2025
• Primary Completion (Estimated): July 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: September 23, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

DE (1)