Nutrition and disease course in inflammatory bowel disease: studies on dietary intake and nutritional status

Inflammatory bowel disease (IBD) is a chronic, inflammatory disorder of the gastrointestinal tract, with Crohn’s disease (CD) and ulcerative colitis as main entities. Both are characterized by episodes of active inflammation (flares) alternated by periods of inactive disease (remission). The exact causes of IBD are not yet clear, though it has been shown that a genetic susceptibility, a disturbed immune function, the intestinal microbiota, and environmental factors play a role. Diet is thought to be an important environmental risk factor because of the rising incidence of IBD in line with the adoption of a Western lifestyle. Exact dietary triggers are however not clear. Patients also consider diet as an important contributor of disease flares and adjust their diet accordingly, often without dietary guidance. This puts patients at risk of developing malnutrition. The aim of this thesis was to gain further insight into diet and IBD by evaluation I) habitual dietary intake and the association with flare occurrence, and II) the assessment of malnutrition and its association with disease course