Abstract: Obesity is a chronic, progressive, and systemic disease that profoundly reshapes the landscape of digestive health. Beyond excess adiposity, it constitutes a multifactorial condition driven by complex interactions among genetic, metabolic, microbiological, and social determinants. This narrative review delineates the extensive and heterogeneous impact of obesity across the digestive tract, with a particular emphasis on metabolic dysfunction-associated steatotic liver disease, now the most prevalent chronic liver condition globally and a leading indication for liver transplantation. Obesity also modulates the pathophysiology, severity, and prognosis of functional gastrointestinal disorders, biliopancreatic diseases, inflammatory bowel disease, and digestive cancers, through mechanisms involving visceral adiposity, low-grade systemic inflammation, gut-brain axis disruption, and intestinal dysbiosis. The review highlights the emerging role of endoscopic bariatric therapies -especially endoscopic sleeve gastroplasty- as minimally invasive interventions that modulate enteroendocrine signaling, improve liver histology, and achieve sustained metabolic benefits. Beyond the clinical realm, the article addresses the ethical imperative of destigmatizing obesity, the impact of food insecurity and health inequities on digestive outcomes, and the critical need for a multidisciplinary, patient-centered, and precision-based approach to digestive care. Gastroenterologists are called to transcend traditional boundaries, assuming leadership in prevention, early detection, and integrated management of obesity and its digestive sequelae. In doing so, digestive medicine becomes not only a responder to the consequences of obesity, but an active agent in transforming one of the most urgent public health challenges of the 21st century.
