Impact of Obesity and Its Treatment on Inflammatory Bowel Disease Outcomes: A Narrative Review

Abstract

Obesity is a chronic inflammatory condition whose rising incidence has turned it into a global epidemic, a trend that also affects people living with inflammatory bowel diseases (IBD). Recent epidemiological data indicate that roughly 25 to 40% of patients with IBD are overweight and that 15 to 40% have obesity. Obesity can contribute to the pathogenesis of IBD and acts as a negative prognostic factor for disease course, response to pharmacological treatment, hospitalizations, post-surgical complications, and quality of life. Overall, the rate of adverse events related to the intestinal disease is higher in patients with obesity, and early data suggest that exposure to weight-loss interventions is associated with more favourable disease outcomes. The relationship between obesity and IBD is complex and involves systemic inflammation, increased production of proinflammatory cytokines, greater intestinal permeability, microbiota alterations, dietary patterns, and hormonal changes. Weight loss interventions, including lifestyle modification, pharmacological treatment, and bariatric surgery, appear to influence IBD-related outcomes, with growing attention to the emerging role of glucagon-like peptide-1 (GLP-1) receptor agonists. Several questions remain open and could guide future research, since a full understanding of the interplay between IBD and obesity is crucial for effective personalized treatment.