1. Department of Nutrition, Food Safety and Toxicology West China School of Public Health Sichuan University Chengdu China
2. School of Public Health Tongji Medical College Huazhong University of Science and Technology Wuhan China
3. Department of Obstetrics West China Women's and Children's Hospital Sichuan University Chengdu China
4. Research Centre for Public Health and Preventive Medicine West China School of Public Health Sichuan University Chengdu China