Background <p>Inflammatory Bowel Disease (IBD) involves genetic and environmental factors, but the relationship between disease activity, adiposity, and diet remains unclear.</p> Objective <p>To investigate the association between endoscopic/radiological activity of IBD, body adiposity, and the Dietary Inflammatory Index with or without adjustment for energy density (E-DII or DII).</p> Method <p>An observational, cross-sectional study was carried out. Endoscopic activity was defined by an endoscopic Mayo score &gt;2, Crohn’s Disease Endoscopic Index of Severity (CDEIS) &gt; 5, and/or the presence of a deep ulcer in any intestinal segment. Body adiposity was estimated using the body mass index, waist circumference, and waist-hip ratio (WHR). The DII and E-DII scores were calculated from a validated quantitative food frequency questionnaire. According to the DII and E-DII, the patients were divided into three groups: the first with the least pro-inflammatory diet and the third with a predominantly pro-inflammatory diet.</p> Results <p>Of the 62 patients, 58.1% (<i>n</i> = 36) were in remission (RD) and 41.9% (<i>n</i> = 26) had active disease (AD). The proportion of patients with overweight/obesity was 69.4% (<i>n</i> = 25) in the RD group and 50.0% (<i>n</i> = 13) in the AD group. Patients in remission exhibited significantly higher WHR (<i>p</i> &lt; 0.05) and a greater frequency of central obesity (<i>p</i> &lt; 0.01). A predominantly pro-inflammatory diet was common across both groups; 58.3% (<i>n</i> = 21) of RD patients and 50.0% (<i>n</i> = 13) of AD patients were in the highest DII tertile. Similar results were found for the E-DII.</p> Conclusions <p>Among patients with IBD, pro-inflammatory dietary patterns and excess adiposity are highly prevalent. Despite greater central adiposity in patients in remission, no significant associations were found between DII or EDII scores and endoscopic and radiological markers of disease activity.</p>