Background and aims:
Inflammatory bowel disease (IBD) is associated with malnutrition, which can further affect disease course and quality of life. Therefore, guidelines advocate screening of patients in clinical practice. However, the prevalence of malnutrition varies widely, due to differences in populations included and parameters used. The primary aim of the present study was to assess the prevalence of malnutrition using single and a combined set of parameters. Secondary aims were i) to evaluate the accuracy of screening recommendations given in current IBD guidelines and ii) to explore which patients have an increased risk of malnutrition.

Methods:
Malnutrition was defined by the Global Leadership Initiative on Malnutrition (GLIM) criteria and by single parameters for impaired body composition, muscle strength or caloric intake. Independent risk factors (i.e. clinical and demographic factors) for malnutrition were analyzed by multivariable logistic regression.

Results:
Of 200 included patients (139 CD, 61 UC), 40 (20%) fulfilled the GLIM criteria, and 94 (47.0%) had at least one parameter for malnutrition impaired. The fat free mass index was most often affected. When applying screening according to current IBD guidelines, only 32 patients were identified. Only female sex was associated with malnutrition (OR 2.57, 95% CI 1.40-4.72).

Conclusion:
In total, 40 patients fulfilled the GLIM criteria and almost half of the IBD outpatients had malnutrition as defined by various single parameters and irrespective of disease characteristics. Screening for malnutrition is recommend for all IBD outpatients by multiple parameters, with special attention for assessing fat free mass and reduced intake.