Self-perceived Weight and Mortality in Korean Adults Based on the Korea National Health and Nutrition Examination Survey Data Linked to Cause of Death Statistics.

This study aimed to determine the associations between self-perceived weight, weight perception, and mortality risk among Korean adults.
Data from the 2007 to 2015 Korea National Health and Nutrition Examination Survey and the 2007 to 2019 Cause of Death Statistics were linked for this cohort study. A complex samples Cox regression analysis involving 42,453 participants (17,056 men; 25,397 women) was performed after excluding those who died within 1 year of the follow-up period, those with a history of cancer, those with cardiovascular diseases, those without body mass index (BMI) data, and those without self-perceived weight data.
During 7.85 years of follow-up, the overall mortality rate was 3.8% (4.5% for men and 3.1% for women). Self-perceived thin weight status was associated with a 43% to 68% higher risk of all-cause mortality and a 2.48-times higher risk of cardiovascular mortality compared to self-perceived appropriate weight status after controlling for sociodemographic characteristics, health-related behaviors, underlying health status, BMI, and metabolic syndrome. After adjusting for the confounding factors, those who underestimated their weight had a 27% reduced risk of all-cause mortality than those who correctly estimated their weight. The risks of all-cause mortality and cardiovascular mortality were 2.14-times higher and 2.32-times higher, respectively, in the underweight group with an accurate weight estimation than in the normal weight group with an accurate weight estimation. However, all-cause mortality was 47% lower among participants with obesity who overestimated their weight.
Self-perceived thinness and accurately perceived underweight status were associated with increased risks of all-cause mortality and cardiovascular mortality among Korean adults.