Diet & Nutrition—What’s Evidence-Based

Eating well supports overall health in inflammatory bowel disease (IBD), but diet alone does not replace medical treatment. Research favors a Mediterranean-style pattern for most people, while certain targeted diets can help specific problems, like symptom flares or irritable bowel syndrome (IBS)-type symptoms. Monitoring for vitamin and mineral deficiencies matters. A registered dietitian can tailor plans for strictures, weight loss, surgery, pregnancy, or pediatric needs. (pubmed.ncbi.nlm.nih.gov)

Key takeaways

• No single adult IBD diet prevents flares. A Mediterranean-style pattern is a safe default. (pubmed.ncbi.nlm.nih.gov)

• Limit ultra-processed foods. Higher intake is linked to increased IBD risk. (pubmed.ncbi.nlm.nih.gov)

• Exclusive enteral nutrition and the Crohn’s Disease Exclusion Diet help selected Crohn’s scenarios, especially in children. (pubmed.ncbi.nlm.nih.gov)

• Low FODMAP reduces IBS-like symptoms in IBD, not inflammation, and should be dietitian-guided. (pubmed.ncbi.nlm.nih.gov)

• Screen regularly for vitamin D, iron, and, with ileal disease or surgery, vitamin B12; correct deficiencies. (gastroenterology.acponline.org)

• See a dietitian for new diagnosis, weight loss, strictures, surgery planning, pregnancy, pediatrics, or if considering restrictive diets. (pubmed.ncbi.nlm.nih.gov)

What diet can and cannot do in IBD

• Diet influences symptoms and quality of life. In adults, no single diet consistently reduces relapse rates, so medicines remain the foundation of control. Mediterranean-style eating is advised unless contraindicated. (pubmed.ncbi.nlm.nih.gov)

• Processed food quality matters. Large cohort data link higher ultra-processed food intake with higher IBD risk, so focusing on minimally processed foods is reasonable. (pubmed.ncbi.nlm.nih.gov)

A realistic default: the Mediterranean-style pattern

A Mediterranean-style diet emphasizes vegetables and fruits, legumes, whole grains, nuts, olive oil, fish and poultry, and limits red and processed meat, added sugar, salt, and ultra-processed foods. It is practical, nutrient dense, and supports heart and bone health. In Crohn’s, it improved symptoms as much as the Specific Carbohydrate Diet, with easier adherence. (pubmed.ncbi.nlm.nih.gov)

Practical plate in remission: half colorful produce, one quarter lean protein, one quarter whole grains, plus olive oil or other unsaturated fats. If a stricture causes food hang‑up, prioritize texture changes, for example cooked, peeled, blended produce and careful chewing, rather than avoiding plants altogether. (pubmed.ncbi.nlm.nih.gov)

Targeted approaches by goal

During flares or with strictures

• Short-term, low-residue or soft-texture eating can reduce stool volume and ease symptoms. Re-expand fiber as inflammation settles. For strictures, use peeling, cooking, blending, and avoid tough meats and stringy, seedy items. (medlineplus.gov)

Inducing remission without steroids in Crohn’s

• Exclusive enteral nutrition (all-calorie liquid formulas) induces remission and mucosal improvement, with strongest evidence in children; adults may also benefit in select cases or before surgery. (gastro.org)

• Crohn’s Disease Exclusion Diet plus partial enteral nutrition is better tolerated than exclusive formulas in children and can sustain remission; early adult data show promise. Discuss feasibility and monitoring with a dietitian. (pubmed.ncbi.nlm.nih.gov)

• Before elective Crohn’s surgery, several studies and meta-analyses link preoperative exclusive enteral nutrition with fewer postoperative infections and leaks. (pubmed.ncbi.nlm.nih.gov)

IBS-like symptoms in IBD remission

• A structured low FODMAP plan can lessen bloating, pain, and gas in IBD with coexisting functional symptoms. It does not treat intestinal inflammation, and long-term restriction risks nutrient gaps, so use it short term with reintroduction under dietitian guidance. (pubmed.ncbi.nlm.nih.gov)

Popular diets and what the evidence shows

• Specific Carbohydrate Diet: In the DINE-CD trial, it was not superior to a Mediterranean diet for Crohn’s symptom remission or biomarkers. Given practicality and broader health gains, Mediterranean is often preferred. (pubmed.ncbi.nlm.nih.gov)

• Gluten-free diet: Unless there is celiac disease or proven wheat sensitivity, evidence does not support gluten avoidance to control IBD. Large cohorts show no link between gluten and IBD risk; a UC trial found no benefit for disease activity. (pmc.ncbi.nlm.nih.gov)

• Probiotics: Routine use in Crohn’s or ulcerative colitis is not recommended. Certain formulations have a role in pouchitis, which is outside everyday UC care. (gastro.org)

Micronutrients to monitor

Deficiencies are common because of reduced intake, malabsorption, or increased needs. Best-practice advice is to regularly screen for vitamin D and iron, and to check vitamin B12 in those with ileal disease or prior ileal surgery. Zinc and folate may also be low, especially in Crohn’s or with chronic diarrhea. Replace documented deficiencies and recheck levels. (gastroenterology.acponline.org)

Quick comparison of diet strategies

When to see a registered dietitian

• New diagnosis, recent weight loss, poor appetite, or low muscle mass

• Iron deficiency, anemia, or low vitamin D, B12, folate, or zinc

• Symptomatic strictures, an ostomy, or short bowel

• Planning for pregnancy, or caring for a child or teen with IBD

• Considering EEN, CDED, low FODMAP, or other restrictive plans

• Preparing for surgery or recovering after surgery

Dietitians are recommended co-managers for complicated IBD, and all newly diagnosed patients should have access when possible. (pubmed.ncbi.nlm.nih.gov)

FAQs

Can diet replace IBD medications

No. In adults, no diet reliably prevents flares. Diet complements, but does not replace, medical therapy. (pubmed.ncbi.nlm.nih.gov)

Should fiber be avoided in IBD

Not in general. In remission, a fiber-rich, plant-forward pattern is appropriate. With strictures or active symptoms, change textures, for example cook, peel, and blend, rather than avoid plants entirely. (pubmed.ncbi.nlm.nih.gov)

Are ultra-processed foods a problem

Higher intake is associated with higher IBD risk. Choose minimally processed foods when possible. (pubmed.ncbi.nlm.nih.gov)

Do probiotics help

They are not recommended for routine Crohn’s or ulcerative colitis care. Some products can help pouchitis, which is a special situation after UC surgery. (gastro.org)