Crohn’s disease (CD) has long been associated with malnutrition, yet the rising prevalence of overweight challenges this traditional paradigm. Adipose tissue is now recognized as a metabolically active organ capable of amplifying systemic and intestinal inflammation, potentially altering disease course and therapeutic requirements. This study aimed to assess the prevalence of overweight among CD patients and determine whether higher BMI is associated with disease severity, complications, and escalation to anti-TNFα therapy.

A cross-sectional study was conducted at Sahloul University Hospital including 157 adults with confirmed CD. Demographic, clinical, Montreal classification, perianal disease, and biological parameters (BMI, CRP, albumin) were collected. Patients were stratified into overweight (BMI ≥ 25 kg/m²) and non-overweight (< 25 kg/m²). Disease complications (strictures, abscesses, fistulas, perianal disease), digestive surgery, and treatment strategies (5-ASA, thiopurines, anti-TNFα monotherapy, combination therapy, and optimization) were compared. Logistic regression identified independent determinants of anti-TNFα use.

The cohort included 157 CD patients (mean age 38.4 ± 12.7 years; sex ratio 1.2). Mean BMI was 22.1 ± 4.3 kg/m², and 24.2% were overweight. Overweight patients were older at inclusion (44.7 ± 10.9 vs 36.5 ± 13.0 years; p = 0.03) and more frequently diagnosed after age 40 (Montreal A3; p = 0.01). Disease location (L1/L2/L3), behavior (B1/B2/B3), perianal involvement, CRP, albumin, and digestive complications did not differ significantly between groups (p > 0.05).However, overweight patients had significantly higher use of anti-TNFα agents (38.9% vs 19.4%; p = 0.03), with more frequent therapeutic optimization (22.2% vs 8.7%; p = 0.02).In multivariate analysis, overweight was the only independent predictor of anti-TNFα initiation (OR 2.45; 95%CI 1.10–5.46; p = 0.028). No association was found between BMI and inflammatory biomarkers.

Overweight affects nearly one-quarter of CD patients and is independently associated with increased need for anti-TNFα therapy and more frequent treatment optimization, despite comparable inflammatory markers and complication rates. These findings suggest that adiposity may modulate therapeutic thresholds in CD and highlight the importance of integrating metabolic status into treatment decision-making.