Diet in inflammatory bowel disease: The Asian Working Group guidelines

The Asian working group has recently released a guideline on diet for inflammatory bowel disease patients. The guideline focuses on clinical nutrition in IBD patients.

This consensus guideline attempts to address the following topics in relation to IBD: (i) role of diet in the pathogenesis; (ii) diet as a therapy; (iii) malnutrition and nutritional assessment of the patients; (iv) dietary recommendations; (v) nutritional rehabilitation; and (vi) nutrition in special situations like surgery, pregnancy, and lactation.

Diet plays a vital role in the pathogenesis of IBD. The increasing incidence of IBD in developing countries like India parallels the westernization of diet, which includes increased intake of fatty food and protein diet and lesser intake of fiber and fruits. Therefore, It is important to study the dietary practices, which keep changing with time and are apparently different in Asian and Western countries.

Consensus recommendations for the medical management of inflammatory bowel disease are as follows

1. Diet has an important role in the pathogenesis of inflammatory bowel disease (IBD), both ulcerative colitis (UC) and Crohn's disease (CD). Grade of recommendation: A, level of evidence: II-2


2. Epidemiological studies indicate that adoption of a Western diet (low in fruits and vegetables, rich in fats, ω-6 fatty acids, red meat, and processed foods) contributes to the increasing incidence of IBD in developing countries. Grade of recommendation: A, level of evidence: II-2


3. Dietary constituents like maltodextrins and emulsifiers may have a role in the development of IBD. Grade of recommendation: B, level of evidence: II-3


4. Vitamin D may have a protective role in the natural history of IBD. Grade of recommendation: B, level of evidence: II-2


5. Breastfeeding may have a protective role in the development of IBD. Grade of recommendation: A, level of evidence: II-2

Diet as a therapy for IBD

1. Exclusive enteral nutrition (EEN) is as effective as steroids in inducing remission in children with luminal Crohn's disease. Grade of recommendation: A, level of evidence: I


2. EEN is effective in adult CD but is inferior to corticosteroids for inducing remission. Grade of recommendation: B, level of evidence: I


3. There is no difference between elemental and polymeric formulae in terms of efficacy. Grade of recommendation: A, level of evidence: I


4. Partial enteral nutrition has been documented to be useful for maintenance of remission in luminal CD along with pharmacotherapy. Grade of recommendation: A, level of evidence: I


5. More evidence is required, before elimination diets such as specific carbohydrate diet (SCD), Crohn's disease exclusion diet (CDED), semi-vegetarian diet, anti-IBD diet, or low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) can be recommended as a therapy for CD. Grade of recommendation: A, level of evidence: II-2


6. There is no specific role for exclusive (EEN) or partial enteral nutrition (PEN) for induction or maintenance of remission in patients with UC. Grade of recommendation: B, level of evidence: I

Malnutrition and nutritional assessment in a patient with IBD

1. Patients with IBD are at a higher risk of malnutrition hence all patients with IBD should be screened for malnutrition at presentation. Grade of recommendation: B, level of evidence: II-2


2. The prevalence of malnutrition in a patient with IBD depends upon disease subtype, severity, extent, and duration. Grade of recommendation: B, level of evidence: II-2


3. Body mass index alone is not sufficient for the nutritional assessment of a patient with IBD. Grade of recommendation: B, level of evidence: II-2


4. Dieticians/nutritionists should be involved in the nutrition care of patients with IBD. Grade of recommendation: B, level of evidence: I

Dietary recommendations in IBD

1. For admitted patients with acute severe ulcerative colitis, adequate oral caloric intake is preferred to bowel rest. Grade of recommendation: A, level of evidence: II-1


2. After stabilization of acute severe ulcerative colitis, a standard diet should be gradually introduced and oral nutritional supplements should not be a routine. Grade of recommendation: B, level of evidence: III


3. For active inflammatory Crohn's disease, an oral diet with high protein is preferred to total parenteral nutrition. Grade of recommendation: A, level of evidence: I


4. Once in remission, there is no need for diet modification or restriction and the patients can continue a normal diet as other family members. Grade of recommendation: B, level of evidence: I


5. No dietary item, in particular, is established to cause a relapse of disease activity in a patient in remission. Grade of recommendation: B, level of evidence: II-1


6. Milk should not be routinely restricted in all patients with IBD unless the patient has severe hypolactasia. Grade of recommendation: A, level of evidence: I


7. A gluten-free diet (GFD) is not of proven value in patients with IBD. Grade of recommendation: B, level of evidence: II-3


8. A low FODMAP diet may help in alleviating irritable bowel syndrome (IBS)-like symptoms associated with IBD. Grade of recommendation: A, level of evidence: I

Nutritional rehabilitation in IBD patients

1. Patients with IBD should receive adequate calories, proteins, and fats in their diet. The calorie and protein requirement of a patient with IBD in remission is similar to that of a healthy individual. However, the protein requirement is increased in a patient with active disease. Grade of recommendation: B, level of evidence: III


2. Patients with IBD who have anemia should be evaluated appropriately for the cause of anemia and adequately treated. Grade of recommendation: B, level of evidence: III


3. Proactive screening for osteopenia and its treatment should be done as per guidelines. Grade of recommendation: A, level of evidence: III


4. Patients should be screened for micronutrient deficiency including calcium, phosphate, magnesium, iron, folic acid, and vitamin B₁₂ in an appropriate clinical context. Grade of recommendation: B, level of evidence: III


5. Except for patients with stricturing CD, there is no evidence for recommending either a low or a high fiber diet for patients with IBD. Grade of recommendation: A, level of evidence: I


6. Patients with IBD should refrain from alcohol consumption as it may worsen the symptoms of disease. Grade of recommendation: B, level of evidence: II-2


7. Patients of IBD should be encouraged to refrain from smoking. Grade of recommendation: A, level of evidence: II-2


8. There is no scientific evidence to recommend probiotics as a food supplement. Grade of recommendation: A, level of evidence: I


9. The nutritional status of patients with IBD should be optimized prior to elective surgery for a better outcome. Grade of recommendation: B, level of evidence: III


10. If the nutritional goals cannot be met with an oral diet alone, oral nutritional supplements (ONS) or enteral nutrition should be initiated prior to surgery/perioperative phase. Grade of recommendation: B, level of evidence: III


11. In elective surgery, the ERAS (early/enhanced recovery after surgery) protocol should be followed in the perioperative period. Grade of recommendation: C, level of evidence: III

Special situations: surgery, ostomies, pregnancy, lactation-

1. Oral diet/EN should be started as soon as the patient can tolerate in the postoperative period. Grade of recommendation: A, level of evidence: I


2. In the postoperative period, if an oral diet cannot be resumed within 7 days, then enteral/parenteral nutrition should be initiated. Grade of recommendation: A, level of evidence: I


3. In CD patients with a fistula, the type of diet depends upon the location of fistula–oral feeds for distal (low ileal or colonic) and low output fistula, and partial or exclusive parenteral nutrition for proximal and high output fistula. Grade of recommendation: B, level of evidence: II-3


4. IBD patients with pregnancy should be specifically evaluated for iron and folate deficiency and replacement done accordingly. Recommended Dietary Allowances (RDA) for pregnancy and lactation should be followed. Grade of recommendation: B, level of evidence: III.

To read the full guideline log on to DOI- https://doi.org/10.1007/s12664-019-00976-1