Department of Bariatric Surgery, the First Affiliated Hospital of Jinan University, No.613, Huangpu Avenue West, Guangzhou, 510630, China. Institute for Physical Activity and Nutrition (IPAN), Deakin University, Melbourne, VIC, 3125, Australia. Faculty of Medicine, University of Ottawa, Ottawa, Canada. Robert H Lurie Medical Research Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA. Department of Bariatric Surgery, the First Affiliated Hospital of Jinan University, No.613, Huangpu Avenue West, Guangzhou, 510630, China. twcc2015@163.com.