| Affiliation: | 1. Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health;2. Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China;3. Department of Epidemiology and Health Policy, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan;4. Research Center for Physical Activity, Diet and Health Promotion, Institute of Sports Science, Department of Physical Education and Sports Science, Peking University, Beijing, China;5. Institute of Population Research, Peking University, Beijing, China |
