1. Department of Endocrinology and Metabolism, Sichuan University, Chengdu, Sichuan, People's Republic of China.
2. Chinese Evidence-Based Medicine Center, Sichuan University, Chengdu, Sichuan, People's Republic of China.
3. Nutrition Department, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China.
4. Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, People's Republic of China.