1. Department of Epidemiology and Biostatistics, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, China.
2. Department of Nursing, Xi'an Jiaotong University Health Science Center, Xi'an, China.
3. Nutrition and Food Safety Engineering Research Center of Shaanxi Province, Xi'an, China.
4. Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, China.