AIM: To evaluate the associated effects of dynapenia and overweight in patients with ulcerative colitis (UC). MATERIALS AND METHODS: Single-center observational cross-sectional case-control study. 80 patients with UC were divided into groups: 14 UC patients with dinapenia and overweight/obesity; UC and dinapenia patients with normal body weight/body weight deficiency (n=12); overweight/obese UC patients (n=24); UC patients with normal body weight/weight deficiency bodies (n=30). The protocol included: the study of nutrition, physical activity, the risk of nutritional insufficiency, measurement of body mass index, blood pressure, dynamometry, duplex scanning of extracranial vessels, determination of the insulin resistance index (HOMA-IR). The assessment of blood composition parameters included studies of blood lipid composition, C-reactive protein, TNF-alpha, glucose, insulin, C-peptide, leptin, adiponectin, leptin receptors. Zonulin has been studied in feces. STATISTICAL METHODS: median (Me), upper and lower quartiles (Q(25), Q(75)); fraction and standard error of the fraction; Mann-Whitney criterion; Kruskal-Wallis criterion; Pearson's chi(2). To identify the statistical relationship, Spearman's correlation coefficient was calculated. Statistical indicators are calculated using Statistica 10.01.1011. RESULTS: Dinapenia in combination with obesity/overweight is observed in 17.5% of patients with UC, most of them patients with low physical activity. Dinapenic obesity is associated with metainflammation and increased permeability of the epithelial barrier, as evidenced by significantly higher rates of C-reactive protein, TNF-alpha, HOMA-IR and fecal zonulin. In patients with dinapenia in combination with overweight/obesity, higher leptin levels were determined, and the leptin receptors level was lower than in participants of other groups. CONCLUSION: The mechanisms of dinapenia in overweight/obese UC patients include a synergistic effect of inflammation, insulin resistance and increased epithelial permeability.