The Causal Relationship Between Obesity and Type 2 Diabetes Mellitus

Scientific Study from the year 2025 in the subject Biology - Diseases, Health, Nutrition, , language: English, abstract: Obesity and Type 2 Diabetes Mellitus (T2DM) are two of the most pressing public health challenges of the 21st century. While their association is well-documented, establishing a causal relationship is vital for guiding effective prevention strategies. This paper applies Bradford Hill’s criteria for causation to systematically assess whether obesity can be considered a direct cause of T2DM. Drawing on evidence from epidemiological studies, clinical trials, and biological mechanisms, the paper evaluates the strength, consistency, temporality, dose-response, plausibility, and experimental support for the link. Findings reveal that obesity satisfies nearly all of Hill’s nine criteria, including strong and consistent associations across populations, well-established temporal precedence, and mechanistic plausibility supported by experimental evidence. The paper concludes that the causal role of obesity in the development of T2DM is robust and should inform policy, clinical interventions, and public health strategies globally.