IBD is a chronic disease mediated by the immune system that is distinguished by the importance of diet in pathological development. The purpose of this study is to learn how the use of predefined diets affects the adult population with IBD. A systematic review and meta-analysis were carried out. We discovered 4195 records using various databases (MEDLINE, Scopus, Cochrane, LILACS, CINAHL, and WOS). Following a review process, only 31 research studies were chosen for qualitative synthesis and 10 for meta-analysis. The variables used were: Crohn's Disease Activity Index (CDAI) for Crohn's Disease (CD) patients and faecal calprotectin (FC), C-Reactive Protein (CRP), and Albumin (ALB) for IBD patients. Prescribed diets are partially effective in the treatment of IBD and are compatible with other medical treatments. CDAI improved, but with reservations due to the high heterogeneity of the data, whereas ALB, FC, and CRP showed no differences. Because diets and the tools used to measure their effects vary so greatly, more studies evaluating the impact of predefined diets on IBD patients are required.
