24-Hour Physical Activity Intensity and Energy Intake Trajectories and Their Associations with All-Cause Mortality: A Population-Based Cohort Study

Diet and physical activity together affect health as important components of energy intake and energy expenditure, but few studies have considered the temporal interaction effect between them. Therefore, this study aimed to identify real-world 24-h physical activity intensity and energy intake trajectories and explore their associations with all-cause mortality. A total of 6389 participants from the 2003-2006 annual survey of the National Health and Nutrition Examination Survey (NHANES) were involved as baseline data in this study. Physical activity data was obtained from the physical activity monitor ActiGraph AM-7164. Energy intake data was collected by the Mobile Examination Center and telephone 3 to 10 days later. All-cause mortality data were obtained in 2019. The group-based trajectory model (GBTM) was used to identify trajectories of 24-h physical activity intensity and 24-h energy intake. Weighted Cox proportional hazard regressions were used to estimate the association between 24-h trajectory groups and all-cause mortality. The 24-h energy intake-physical activity intensity dual trajectories were divided into four groups, including group1 (46.9%): three meals and low active, group2 (36.2%): three meals and moderately active, group3 (8.8%): night eating and moderately active, and group4 (8.1%): three meals and highly active. The dual trajectories were associated with all-cause mortality. Compared to participants with three meals and low activity levels, participants with three meals and moderate activity had a reduced risk of all-cause mortality. In summary, this study found that participants with three meals and moderately active had a lower risk of all-cause mortality.