Multiple paths to health: A scoping review of dietary interventions for adults with Crohn's disease and ulcerative colitis.

Abstract

Background: Patient and clinical interest in dietary management of inflammatory bowel disease (IBD) is growing, yet a comprehensive overview mapping how dietary interventions are defined, composed, and evaluated across Crohn's disease (CD) and ulcerative colitis (UC) remains scarce.

Objectives: This scoping review aims to map current evidence on dietary interventions that may have an impact on the disease course in adults with CD or UC, thereby providing guidance for the design of forthcoming dietary interventions.

Eligibility criteria: Included are English articles published between 2000-2025 investigating dietary treatments for adults (+18) reporting on symptoms, remission, or disease activity. Excluded are paediatric studies, single food/supplement-only interventions, and studies combining new medications with diet.

Sources of evidence: Systematic searches of PubMed, CINAHL, Scopus, and Web of Science, originally conducted in January 2025 and updated in May 2026, identified 49 eligible studies.

Charting methods: Data were charted using Covidence with a form guided by the TIDieR checklist. Dietary composition across interventions was visualised using heatmap analysis.

Results: A range of dietary approaches were identified. Most improved patient-reported outcomes and disease activity indices, though a disconnect often persisted between symptomatic relief and inflammatory biomarker normalization. Despite variability even among nominally identical diets, heatmap analysis of diet composition revealed strong consensus around elimination of processed foods and added sugars, alongside emphasis on whole foods, fruits, vegetables, and unsaturated fats.

Conclusions: Evidence points toward several possible diets for IBD, and clearly toward the Mediterranean diet and shared whole-food principles as a well-supported, safe, and guideline-endorsed foundation. Next step is designing rigorous research with standardised outcomes, disease-specific populations, mechanistic sub-studies, and the implementation support that adherence requires.