Can Diet Quality Be Associated with Disease Activity in a Prospective Dutch IBD Cohort?

<b>Background/Objectives</b>: Inflammatory bowel disease (IBD) is characterized by a relapsing-remitting disease course, influenced by dietary factors. This study aims to examine diet quality in IBD patients and investigate its association with disease activity. <b>Methods:</b> In total, 477 participants from a prospective IBD cohort study at two Dutch hospitals were approached to complete a population-specific food frequency questionnaire (GINQ-FFQ) at baseline and after one year. Disease characteristics were assessed at multiple time points. Food-related Quality of Life (FrQoL) was assessed at baseline. Diet quality was measured via the Dietary Inflammatory Index (DII), Mediterranean Diet Score (MDS), Healthy Diet Indicator score (HDI), ultra-processed food intake, and Principal Component Analysis (PCA) to identify dietary patterns. The outcomes were compared to the general Dutch population. <b>Results</b>: In total, 191 participants completed the GINQ-FFQ at baseline, of whom 53 had active disease. Patients in remission had higher FrQoL than patients with active disease (<i>p</i> = 0.020). Diet quality and adherence to specific dietary patterns were not associated with disease activity. However, logistic regression showed a trend toward increased odds of increase in disease activity with an animal protein-rich pattern (OR: 1.479, <i>p</i> = 0.088) and a potential association between the Convenience diet and decreased disease activity (OR: 1.396, <i>p</i> = 0.060). Both the Dutch population and the patient cohort scored poor on all diet quality scores. <b>Conclusions</b>: The current study shows no conclusive evidence of an association between disease activity and both diet quality and dietary patterns in patients with IBD. However, the findings do suggest a possible association between animal protein-rich diets with more disease activity and Convenience-like diets with less disease activity. Furthermore, a similar diet quality was observed in IBD patients and the general Dutch population. Nevertheless, diet quality was generally poor and can be improved.