Funding for this research was provided by:
the Special Funds of Basic Research of Central Public Welfare Institute (No. ZX1902)
National Natural Science Foundation of China (No. 81703216, No. 31901698)
the Major scientific and technological innovation projects of Shandong Province (No. 2019TSLH0801)
Received: 12 July 2020
Accepted: 20 September 2021
First Online: 3 October 2021
: This survey was ethically approved by the Ethical Committee of the National Institute for Nutrition and Food Safety, Chinese Center for Disease Control and Prevention (2013-018). Written informed consent was obtained from all participants.
: All authors have read and agreed to the published version of the manuscript.
: The authors declare that they have no competing interests.