Received: 23 June 2020
Accepted: 3 February 2021
First Online: 9 February 2021
Ethics approval and consent to participate
: The National Health and Nutrition Examination Survey, conducted under Article 16 of the National Health Promotion Act, is a statutory survey addressing the health behavior, prevalence of chronic disease, and food and nutrition intake of Korean citizens, and is a government-designated statistic based on Article 17 of the Statistics Act (Approval No. 117002). The survey was conducted every three years from the first (1998) to the third (2005) period. After its reorganization into an annual survey system, it has been conducted annually from the fourth period (2007–2009). It corresponds to research conducted by the government for public welfare in accordance with the Bioethics Act. The original survey data are freely accessible without any administrative permission as open-access resources through the website of the Korean Centers for Disease Control and Prevention (ExternalRef removed). The National Health and Nutrition Examination Survey was conducted with the approval of the Institutional Review Board of Korea Centers for Disease Control and Prevention (Reference numbers 2008-04EXP-01-C and 2009-01CON-03-2C). Informed consent was obtained from every participant at the time when the surveys were conducted. The present study was approved for waiver of review by the Chungnam National University Hospital Institutional Review Board (Daejeon, South Korea; Institutional Review Board number: 2020-04-102).