Unhealthy diet is one of the leading risk factors for morbidity and mortality of chronic diseases including IHD,stroke,diabetes,and cancers.A recent GBD report ranked unhealthy diet as the top risk factors in China,accounting for 16%of DALYs and 31%of deaths.However,most of the existing evidence on diet-disease associations is from Western countries and data from China is of critical importance for the development of evidence-based dietary guidance and precision nutrition.