Obesity Paradox in Critically Ill Patients: Do Patients with Critical Diseases Benefit from Obesity?

Background: Overweight and obesity are linked to an elevated risk of numerous serious diseases and health conditions. Despite the detrimental effects associated with these conditions, recent studies have indicated that critically ill patients may experience a survival advantage with higher body mass index. Initial research on the obesity paradox primarily concentrated on cardiovascular diseases (CVDs), such as heart failure (HF); however, this focus has now expanded to encompass other critical illnesses, particularly sepsis, Acute Respiratory Distress Syndrome (ARDS), trauma, and others. Although the obesity paradox has been extensively documented in research, its origins and implications remain subjects of contentious debate. Summary: This review elucidates the phenomena and underlying mechanisms supporting the obesity paradox, critically examines recent evidence regarding this paradox in severe diseases, and aims to enhance prognostic assessments and therapeutic strategies in clinical practice. Key Messages: The obesity paradox exists in multiple kinds of critically ill patients caused by such as sepsis, lung diseases, and CVD. Even obesity does not protect obese patients; it has no association with mortality.