This study is testing how overweight and obesity affect cardiovascular disease (CVD) prevalence, risk factors, and mortality among Chinese adults using nationally representative CCDRFS (China Chronic Disease and Risk Factor Surveillance) data. The purpose of the study is to characterize trends and determinants of CVD in adults with overweight or obesity and to quantify the excess mortality and population burden attributable to overweight/obesity. Participants will not receive any study medicine as this is an observational analysis of existing survey and mortality data. The study does not involve a new investigational drug; it analyses health and outcome data collected in routine practice and national surveys. The study will last for the duration needed to analyse the CCDRFS datasets and linked mortality follow-up.