Minimum changes in sleep, physical activity, and nutrition associated with clinically important reductions in all-cause mortality risk: a prospective cohort study

Background: Sleep, physical activity, and nutrition (SPAN) are crucial modifiable factors for health, yet most research has examined them independently rather than exploring their combined and incremental impact on disease risk and mortality. Objective: To determine the collective associations of SPAN exposures and establish clinically relevant targets for reducing all-cause mortality risk. Methods: This study included 59,078 UK Biobank participants with valid wearable tracker and nutrition data (Median age [IQR]: 64.0 [7.8] years; 45.4% male). Sleep duration (hours/day) and moderate to vigorous physical activity duration (MVPA; mins/day) were calculated using a machine learning based wearable data schema. A 10-item diet quality score (DQS) assessed the consumption of vegetables, fruits, fish, dairy, whole grains, and vegetable oils, as well as lower intakes of refined grains, processed meats, unprocessed red meats, and sugar-sweetened beverages using a food frequency questionnaire. The DQS assigned values from 0-10 for each component, totalling 100 points, with higher values indicating higher diet quality. Associations with all-cause mortality were explored using Cox proportional hazard models with combinations of SPAN exposure tertiles. Results: During the median 8.1-year follow-up period, 2,458 deaths occurred. MVPA exhibited the strongest overall effect on mortality risk, followed by sleep (with a U-shaped relationship), and diet quality. Compared to the referent group of combined SPAN exposure (lowest tertiles for all three behaviours), the optimal SPAN combination involving moderate sleep duration (7.2-8.0 hours/day), high MVPA (42-103 mins/day), and high DQS (57.5-72.5) was associated with a hazard ratio (HR) of 0.45 (95% CI: 0.37, 0.53). Relative to the 5th percentile of sleep (5.5 hours/day), physical activity (7.3 mins/day), and nutrition (36.9 DQS), a minimum increase of 15 mins/day of sleep, 1.6 min/day MVPA, and 5 DQS points was associated with a 10% reduction in all-cause mortality risk (HR: 0.90; 95% CI: 0.88, 0.93). Additionally, compared to the referent group, an additional 75 mins/day of sleep, 12.5 min/day MVPA, and 25 DQS points was associated with a 50% reduction in all-cause mortality risk (HR: 0.50; 95%CI: 0.44, 0.58). Conclusion: These findings underscore the importance of combined incremental lifestyle modifications in reducing the risk of all-cause mortality. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by an Australian National Health and Medical Research Council (NHMRC) Investigator Grant (APP1194510). ### 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: All participants completed informed consent and the ethical approval was completed by the UK National Health service (NHS) and National Research Ethics Service for the UK (No. 11/NW/0382). 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 The data that support the findings of this study are available from the UK Biobank, but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with the permission of the UK Biobank.