The pursuit of lifespan extension has traditionally focused on disease treatment rather than the preservation of adaptive physiological resilience. Emerging evidence suggests that metabolic flexibility, defined as the capacity to efficiently switch between energy substrates in response to changing physiological demands, may represent a central determinant of healthy aging and longevity. From a surgical perspective, metabolic flexibility influences perioperative recovery, tissue repair, inflammatory regulation, mitochondrial efficiency, and functional independence. This review synthesizes current evidence regarding the biological mechanisms connecting metabolic flexibility with lifespan optimization and examines the clinical implications of metabolic adaptability across aging populations.

The review adopts a surgeon-led analytical framework integrating concepts from geroscience, mitochondrial biology, inflammaging, physiological resilience, and functional biomarkers. Existing literature demonstrates that impaired metabolic flexibility contributes to mitochondrial dysfunction, chronic inflammation, sarcopenia, reduced mobility, and diminished stress adaptation, all of which accelerate biological aging. Conversely, enhanced metabolic adaptability supports cellular homeostasis, promotes recovery from physiological stressors, and improves long-term health outcomes.

The findings indicate that metabolic flexibility functions as a multidimensional determinant of longevity through its influence on energy metabolism, immune regulation, musculoskeletal integrity, and surgical recovery. The analysis further highlights the potential of clinical biomarkers such as grip strength and gait speed as practical indicators of metabolic resilience. The study concludes that lifespan optimization strategies should prioritize the restoration and preservation of metabolic adaptability rather than focusing exclusively on disease-specific interventions. Future translational research should establish standardized clinical frameworks for assessing and enhancing metabolic flexibility across the lifespan.