Global Obesity Epidemic Triples Since 1975, Redefined as Multisystem Disease, GLP-1/GIP Agonists Emerge as Key Therapies

The global obesity epidemic represents a critical public health challenge, with its prevalence escalating dramatically worldwide. Traditionally defined by Body Mass Index (BMI), the understanding of obesity has evolved, recognizing it as a complex, multisystem disease characterized by excess adiposity leading to organ dysfunction. This redefinition, distinguishing between preclinical and clinical obesity, highlights the importance of ectopic fat deposition in the liver, muscle, and viscera as a more accurate predictor of cardiometabolic and hepatic risk than BMI alone. Current standard-of-care often struggles to address the multifaceted nature of the disease and its widespread complications, necessitating novel therapeutic and policy approaches.

This review synthesizes current epidemiological data on the global obesity epidemic, its substantial health burden, and critical policy priorities. It incorporates the 2025 Lancet Diabetes & Endocrinology Commission's redefinition of obesity as a chronic, multisystem disease, moving beyond sole reliance on BMI. The analysis examines global prevalence trends, the economic impact of obesity, and the role of emerging pharmacotherapies, specifically glucagon-like peptide-1 (GLP-1) and dual GLP-1/glucose-dependent insulinotropic peptide (GIP) receptor agonists, in managing associated cardiovascular, metabolic, and hepatic complications. The review aims to inform future strategies integrating precision medicine with scalable public health policies.

The global prevalence of obesity has increased more than threefold since 1975, now impacting nearly one billion adults and over 170 million children and adolescents. The 2025 Lancet Diabetes & Endocrinology Commission redefined obesity as a chronic, multisystem disease, emphasizing ectopic fat deposition over BMI as a key determinant of cardiometabolic and hepatic risk. Obesity is increasingly prevalent in rural and low- to middle-income countries, driven by lifestyle changes. This escalation parallels a rise in non-communicable diseases, with obesity underpinning cardiovascular, metabolic, hepatic, renal, respiratory, oncological, and psychological disorders. Cardiovascular disease remains the leading cause of obesity-related mortality, while type 2 diabetes, metabolic dysfunction-associated steatotic liver disease (MASLD), and chronic kidney disease contribute significantly to morbidity. Economically, obesity accounted for 2.2% of global GDP in 2019 and is projected to exceed 3% by 2060. > Emerging therapies, particularly GLP-1 and dual GLP-1/GIP receptor agonists, achieve weight loss comparable to metabolic bariatric surgery and reduce cardiovascular, metabolic, and hepatic complications, often independent of weight loss.