Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China; Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China; Department of Clinical Nutrition, Guangzhou Red Cross Hospital, Jinan University, Guangzhou, People's Republic of China. Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China; School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, People's Republic of China. Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China; Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China. Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China; Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China. Electronic address: zhuhl@mail.sysu.edu.cn.