A simulation study of the impact of population-wide lifestyle modifications on life expectancy in the Chinese population

Abstract

It is uncertain how much life expectancy of the Chinese population would improve under current and greater policy targets on lifestyle-based risk factors for chronic diseases and mortality. Here we report a simulation of how improvements in four risk factors, namely smoking, alcohol use, physical activity and diet, could affect mortality. We show that in the ideal scenario, that is, all people who currently smoke quit smoking, excessive alcohol use was reduced to moderate intake, people under 65 increased moderate physical activity by one hour and those aged 65 and older increased by half an hour per day, and all participants ate 200 g more fresh fruits and 50 g more fish/seafood per day, life expectancy at age 30 would increase by 4.83 and 5.39 years for men and women, respectively. In a more moderate risk reduction scenario referred to as the practical scenario, where improvements in each lifestyle factor were approximately halved, the gains in life expectancy at age 30 could be half those of the ideal scenario. However, the possibility to realize these estimates in practise may be influenced by population-wide adherence to lifestyle recommendations.

Fig. 1. Distribution of 5-year mortality risk in the base and simulated scenarios for men and women.

In the base scenario (red), exposure patterns for all lifestyle factors remained unchanged. In the simulated scenario (blue), all factors were set to the ideal scenario described in Table 3. The vertical lines indicate the mean 5-year mortality risk for each scenario. Source data are provided as a Source Data file.

Fig. 2. Gained life years at age 30 for men and women from adopting combined low-risk lifestyle habits, with the target population having different age ranges.

The definitions of ideal (dark blue) and practical (dark yellow) scenarios for each lifestyle factor are described in Table 3. Results are derived from 31,515 men and 36,049 women with complete survey data on lifestyle factors in the China Nutrition and Health Surveillance (CNHS) study. Data are presented as point estimates of gained life years (centers of error bars) and the corresponding 95% confidence limits (error bars). Source data are provided as a Source Data file.