1. School of Nursing, Sun Yat-sen University, Guangzhou, Guangdong, China
2. Department of Gastric Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China;
3. Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Guangzhou, Guangdong, China
4. Department of Clinical Nutrition, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
5. State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China