Physical activity and fiber intake beneficial for muscle mass and strength preservation during aging: A Comprehensive Cross-Sectional Study in the UK Biobank cohort

Background Aging triggers intricate physiological changes, particularly in muscle mass and strength, affecting overall health and independence. Despite existing research, the broader significance of how muscle health is affected by the intricate interplay of lifestyle factors simultaneously during aging needs more exploration. This study aims to examine how nutrition, exercise, and sleep independently and differentially impact on muscle mass and strength in middle-aged men and women, facilitating future personalized recommendations for preserving muscle health. Methods The cross-sectional analysis of the UK Biobank involved 45,984 individuals aged 40-70. Multiple linear regression explored determinants of whole-body fat-free mass and handgrip strength, considering traditional, socio-demographics, medication use and smoking as covariates, with gender and age (younger and older than 55 years) stratifications. Results Higher physical activity and fiber intake beneficially affect both muscle mass and strength, especially above 55 years. Other lifestyle factors influence the two muscle parameters differently. Key determinants influencing muscle strength included higher protein intake, lower water intake, higher alcohol intake, and extended sleep duration whereas mainly higher water intake contributes to higher muscle mass. Conclusions Physical activity and fiber intake associate with increased muscle strength and mass which may connect gut and muscle health. Given the observed complexity of muscle health in the age and gender strata, further longitudinal research is needed to provide personalized lifestyle recommendations. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work is funded by the VOILA Consortium (ZonMw 457001001), which had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical clearance for this research was acquired under the broad ethical approval secured by UK Biobank investigators from the National Health Service National Research Ethics Service. The present analyses were conducted in accordance with application number 78275. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors