Narrative Review of the Relationship between Obesity and Type 2 Diabetes

Rukundo Sande Kibuuka

 

Faculty of Science and Technology Kampala International University Uganda

ABSTRACT

The global coexistence of obesity and type 2 diabetes mellitus (T2DM), frequently termed “diabesity,” represents one of the most pressing metabolic challenges of the 21st century. This narrative review synthesizes epidemiological, mechanistic, clinical, and public health evidence to elucidate the bidirectional and multifactorial relationship between obesity and T2DM. Obesity significantly increases the risk of T2DM through interconnected pathways involving insulin resistance, β-cell dysfunction, adipose-tissue endocrine dysregulation, chronic low-grade inflammation, and lipotoxicity driven by ectopic fat deposition. Additional mechanisms include alterations in gut microbiota composition, genetic and epigenetic variations, and life-course exposures beginning in early childhood. The review highlights distinct obesity phenotypes, particularly metabolically unhealthy obesity, visceral adiposity, and ectopic fat patterns, as more strongly predictive of diabetes than BMI alone. Conversely, metabolically healthy obesity appears to confer comparatively lower but still elevated risk. Clinically, intentional and sustained weight loss improves glycaemic outcomes and can induce diabetes remission, while pharmacologic and surgical interventions further support metabolic recovery. Public health evidence underscores the need for multisectoral strategies targeting food environments, early-life nutrition, and community-level lifestyle interventions. Despite extensive research, critical gaps persist regarding causality, genetic interactions, longitudinal trajectories, and the mechanistic contributions of microbiota and environmental exposures. Advancing precision-based prevention and treatment approaches requires integrated, multi-omics, and life-course studies to deepen understanding of the obesity, T2DM nexus and inform more effective interventions.

Keywords: Obesity, Type 2 diabetes mellitus (T2DM), Insulin resistance, Visceral and ectopic fat, and Metabolic dysregulation.

CITE AS: Rukundo Sande Kibuuka. (2026). Narrative Review of the Relationship between Obesity and Type 2 Diabetes. IDOSR JOURNAL OF SCIENTIFIC RESEARCH 11(1):111-116. https://doi.org/10.59298/IDOSRJSR/2026/11.1.111116