The overall quality of evidence of recommendations surrounding nutrition and diet in inflammatory bowel disease

Abstract

Background and aim: Recently, there has been an increased focus on the role nutrition and diet play in maintaining health in inflammatory bowel disease (IBD). We aimed to assess the overall quality, strength, and transparency of conflicts among guidelines on nutrition/diet in IBD.

Methods: A systematic search was performed on multiple databases from inception until January 1, 2021, to identify guidelines pertaining to nutrition or diet in IBD. All guidelines were reviewed for disclosure of conflicts of interest (COI) and funding, recommendation quality and strength, external document review, patient representation, and plans for update-as per Institute of Medicine (IOM) standards. In addition, recommendations and their quality were compared between guidelines/societies.​ RESULTS: Seventeen distinct societies and a total of 228 recommendations were included. Not all guidelines provided recommendations on key aspects of diet-such as the role of supplements or the appropriate micro/macro nutrition in IBD. Fifty-nine percent of guidelines reported on COI, 24% underwent external review, and 41% included patient representation. 18.4%, 25.9%, and 55.7% of recommendations were based on high-, moderate-, and low-quality evidence, respectively. 10.5%, 24.6%, and 64.9% of recommendations were strong, weak/conditional, and did not provide a strength, respectively. The proportion of high-quality evidence (p = 0.12) and strong recommendations (p = 0.83) did not significantly differ across societies.

Conclusions: Many guidelines do not provide recommendations on key aspects of diet/nutrition in IBD. As over 50% of recommendations are based on low-quality evidence, further studies on nutrition/diet in IBD are warranted to improve the overall quality of evidence.

Keywords: Diet; Guidelines; Inflammatory bowel disease; Nutrition; Scientific evidence.