The purpose of malnutrition screening is to predict the probability of a worse outcome due to nutritional factors. The Malnutrition Universal Screening Tool (MUST) can be used for screening in inflammatory bowel disease (IBD); however, it does not provide details about body composition. Our aim was to assess the body composition and combine this with the MUST method to screen risk of malnutrition and sarcopenia. A total of 173 IBD outpatients were enrolled in this cross-sectional study. The MUST scale indicated 21.4% of IBD patients to be at risk of malnutrition. A risk of sarcopenia was detected in 27.7%. However, one third of these patients were not considered to be at risk by their MUST score. Furthermore, Crohn's disease (CD) patients had a strongly unfavorable fat-free mass index (FFMI) value compared to ulcerative colitis (UC) patients, and these differences were significant among men (FFMI: 18.62 ± 2.16 vs 19.85 ± 2.22, p = 0.02, in CD and UC males, respectively). As sarcopenia is a relevant prognostic factor, the MUST method should be expanded to include body composition analysis to detect more IBD patients at risk of malnutrition and sarcopenia in order to start their nutritional therapy immediately.

Our findings suggest that muscle parameters improved during the anti-TNF induction therapy, while fat parameters did not change significantly. Thus, induction anti-TNF therapy might have a beneficial effect on body composition.