The effect of early time-restricted eating on muscle damage-related biomarkers and anxiety in older men

This study investigates the effects of early Time-Restricted Eating (eTRE) on body composition, biochemical markers of muscle damage, and anxiety levels in healthy elderly men. Thirty participants were randomly assigned to either an eTRE intervention group or a control group. The eTRE group consumed all daily caloric intake within an 8-h window (7:00 AM to 3:00 PM) for a period of two months, while the control group maintained their usual eating habits. Assessments were conducted at baseline (T0) and post-intervention (T1), including anthropometric measurements, blood biomarker analysis, and anxiety evaluation using the State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA). Within-group analyses using the Wilcoxon signed-rank test and paired t-test revealed significant improvements in weight, body mass index (BMI), body fat, and fat-free mass in the eTRE group (all p < 0.01). Significant decreases were also found in muscle damage and inflammation markers, including CPK (p = 0.0067), AST (p < 0.0001), CRP (p = 0.0011), and bilirubin (p = 0.044), indicating reduced physiological stress and improved liver function. Two-way repeated measures ANOVA revealed significant time by group interactions for BMI (F₁,₂₈ = 4.453; p = 0.007), body fat (F₁,₂₈ = 3.059; p = 0.037), fat-free mass (F₁,₂₈ = 3.908; p = 0.014), uric acid (F₁,₂₈ = 4.947; p = 0.004), CRP (F₁,₂₈ = 2.853; p = 0.045), AST (F₁,₂₈ = 14.332; p < 0.001), and STICSA scales (p < 0.05). These interactions indicate that the observed changes were significantly more pronounced in the eTRE group compared to the control group. Mediation analyses revealed that biomarkers related to muscle recovery and metabolic regulation (such as LDH, ALT, and AST) significantly mediated the relationship between eTRE and anxiety reduction. These findings suggest that eTRE may be an effective dietary approach to improve body composition, reduce muscle stress and inflammation, and lower anxiety levels in elderly individuals. Future studies are needed to confirm these effects and explore their long-term sustainability.