The global syndemic of aging and obesity is characterized by chronic, low-grade, systemic, sterile inflammation dubbed ‘inflammaging’ and ‘metaflammation’, respectively. Biomarkers representing dysregulated metabolic and immune-inflammatory phenotypes may serve as early predictors of age-related diseases and surrogate endpoints in intervention trials designed to increased human healthspan. However, the planning of large-scale human studies employing biomarker measurements requires careful assessment of the feasibility and reliability of said measurements. Interestingly, the geroscience hypothesis links the biology of aging with age-related diseases, suggesting that therapies that improve the pillars of aging can improve multiple diseases in parallel. As such, biomarkers of aging are known to associate with multiple age-related diseases.