1. Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, P.R. China.
2. Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou, P.R. China.
3. Department of Medical Statistics & Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, P.R. China.