Nutritional adaptation to circadian misalignment: implications for musculoskeletal health in modern lifestyles.

Circadian rhythms regulate metabolic, endocrine, and cellular processes essential for maintaining musculoskeletal health. Accumulating experimental and epidemiological evidence indicates that circadian disruption, driven by modern lifestyle factors such as shift work, sleep restriction, and irregular eating patterns, is associated with an increased risk of musculoskeletal disorders. This narrative review summarizes current evidence linking circadian misalignment to alterations in bone, skeletal muscle, and cartilage biology. At the mechanistic level, disruption of core clock gene expression and desynchronization between central and peripheral clocks lead to hormonal imbalance, metabolic dysfunction, and chronic low-grade inflammation. These pathways are associated with bone loss, impaired muscle protein synthesis, and accelerated cartilage degeneration. Findings from both animal and human studies support associations with osteoporosis, sarcopenia, and osteoarthritis. Chrononutrition has emerged as a potential strategy to mitigate these effects. Approaches such as time-restricted eating, alignment of food intake with the biological day, and optimized protein distribution may help restore circadian alignment and improve musculoskeletal outcomes. In conclusion, integrating circadian biology with nutritional timing provides a promising framework for the prevention and management of musculoskeletal disorders, although large-scale human interventional trials with validated clinical endpoints are needed to confirm benefit.