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

Abstract

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. 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. 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. Systematic searches of PubMed, CINAHL, Scopus, and Web of Science, originally conducted in January 2025 and updated in May 2026, identified 49 eligible studies. Data were charted using Covidence with a form guided by the TIDieR checklist. Dietary composition across interventions was visualised using heatmap analysis. 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. 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. Both patients and healthcare professionals are interested in how to manage inflammatory bowel disease (IBD) using diet. However, it is still unsure of what these different diets look like and how well they work. Research published between 2000 and 2025 was reviewed to map out the different dietary approaches tested in adults with IBD. The researchers looked at 49 studies to see how the diets were defined, what foods were included and excluded, and what effects they had on symptoms and inflammation. While many diets helped improve how the patients felt, this improvement did not always match up with a reduction in gut inflammation measured by lab tests. Importantly, despite the variety of diet names, most of them shared common principles; cutting out processed foods, added sugar and sugary drinks, and instead a focus on eating whole foods such as fruits, vegetables containing fibre, and healthy fats found in nuts and olive oil. The evidence points to several diets that may be helpful for managing IBD. However, the Mediterranean diet stands out because it is well-supported by research and considered safe. The next step is to conduct more rigorous research that uses standard methods to measure results and better understand how diet works to help manage IBD. For now, focusing on a varied diet containing whole foods appears to be a beneficial strategy.