Figure 1.

Possible mechanisms for metabolically healthy and unhealthy obesity. Storage of excess calories by adipocyte hyperplasia is considered to be healthy because the tissue maintains adequate vascularization and secretion of anti-inflammatory adipokines. Excessive hypertrophy of existing adipocytes is considered unhealthy since cells become inadequately vascularized, hypoxic, and dysfunctional, leading to macrophage invasion and secretion of inflammatory cytokines that may contribute to insulin resistance and other metabolic disorders, exacerbating hypertension, and cardiorenal disease.