Joint Associations of Diet and Device-Measured Physical Activity with Mortality and Incident CVD and Cancer: A Prospective Analysis of the UK Biobank Study

BACKGROUND: We examined the joint associations of diet and device-measured intensity-specific physical activity (PA) with all-cause mortality (ACM), cardiovascular disease (CVD), and cancer incidence. METHODS: We used data from 79,988 participants from the UK Biobank, a population-based prospective cohort study. Light PA (LPA), moderate-to-vigorous PA (MVPA), vigorous PA (VPA), and total PA (TPA) were measured using a wrist-worn accelerometer. Diet quality score (DQS) was based on 10 foods and ranged from 0 (unhealthiest) to 100 (healthiest) points. We derived joint PA and diet variables. Outcomes were ACM, CVD, and cancer incidence including PA, diet and adiposity-related (PDAR) cancer. RESULTS: During a median follow-up of 8 years, 2,863 deaths occurred, 11,053 participants developed CVD, 7,005 developed cancer, and 3,400 developed PDAR cancer. Compared with the least favorable referent group (bottom PA tertile/low DQS), participants with middle and high (total and intensity specific) PA, except for LPA, had lower ACM risk and incident CVD risk, regardless of DQS. For example, among middle and high VPA and high DQS groups, CVD HR were 0.79 (95% CI, 0.74-0.86) and 0.75 (95% CI, 0.69-0.82), respectively. The pattern of cancer results was less pronounced but in agreement with the ACM and CVD incidence findings (e.g., HR, 0.90, 95% CI, 0.81-0.99; 0.88, 0.79-0.98; and 0.82, 0.74-0.92 among high VPA for low, moderate, and high DQS groups, respectively). CONCLUSIONS: Device-measured PA reveals novel joint associations with diet on health outcomes. IMPACT: Our results emphasize the crucial role of PA in addition to a healthy diet for reducing chronic diseases and mortality risk.