The impact of population-wide lifestyle modifications on improving life expectancy in the Chinese population: a simulation study

Background Despite considerable population-wide measures to promote the Chinese population’s healthy lifestyle, it is uncertain how much life expectancy (LE) would improve under current and greater policy targets on lifestyle behaviours. Methods We developed 5-year sex-specific all-cause mortality risk prediction models using data from the China Kadoorie Biobank (CKB). Based on nationally representative survey data from China Nutrition and Health Surveillance (2015), we simulated changes in the prevalence of four lifestyle factors: smoking status, alcohol consumption, total physical activity level, and dietary habits (daily intake amount of fresh fruits and fish/seafood). The LE for each hypothetical lifestyle intervention scenario was calculated based on the age-specific probability of death obtained from the risk prediction models. Results During a median follow-up of 12.1 years, the CKB documented 31,956 deaths in men and 24,593 deaths in women. The prediction models for men and women demonstrated good discrimination, with the overall area under the receiver-operating characteristic curve of 0.800 for men and 0.808 for women. In the ideal scenario of all lifestyle factors, that is, all current smokers quit smoking, excessive alcohol users reduced their alcohol intake to moderate levels, people under 65 and those aged 65 and older increased their physical activity level by one hour and half an hour per day of moderate-intensity physical activity, and all participants ate 200g more fresh fruits and 50g more fish/seafood per day, LE at age 30 would increase by 4.83 (95% confidence interval [CI]: 4.01, 5.82) and 5.39 (95% CI: 4.70, 6.18) years for men and women, respectively. In the practical scenario, where improvements in each of the lifestyle factors were approximately halved, the gains in LE at age 30 for both men and women could be half those of the ideal scenario. Conclusions Our findings reinforce the evidence that population-wide lifestyle modifications can improve the LE of the whole Chinese population. If the current policy targets set by the Healthy China Initiative could be raised, a greater increase in LE would be achieved.