Trendy, but Are They Safe? Current Popular Diets and Their Use in Inflammatory Bowel Diseases: Narrative Review

Abstract

Inflammatory bowel disease (IBD) arises from the interplay between genetic susceptibility, immune dysregulation, microbiota, and environmental exposures, with diet potentially contributing to both pathogenesis and management. Patients frequently modify their diet independently, often using different strategies during remission and active symptoms. This narrative review synthesises evidence on patient-accessible dietary patterns and selected structured nutritional therapies across five domains: incident IBD, objective intestinal inflammation, gastrointestinal symptoms and quality of life, nutritional safety, and real-world feasibility. Mediterranean and other minimally processed plant-forward patterns are associated with higher diet quality and potentially favourable microbial and metabolic profiles; however, current trials do not demonstrate consistent superiority for objective remission or mucosal healing. Western and ultra-processed food-rich patterns are associated with incident IBD, whereas evidence for relapse in established disease is less consistent. Low-FODMAP approaches may improve selected symptoms but should not be interpreted as anti-inflammatory therapy. Evidence for ketogenic and intentional carnivore diets remains insufficient for routine use. Exclusive enteral nutrition and the Crohn’s Disease Exclusion Diet have distinct, protocolised therapeutic roles, particularly in Crohn’s disease. Across strategies, affordability, food security, cooking resources, disease phenotype, nutritional risk, and access to specialist dietetic care determine safe and equitable implementation.