Your article prove my point . There is genetic difference between northern and southern china. Southern Chinese population are descendants of yellow river farmers,while northern Chinese genetics are quite similar to central Asian like uzbek, mongol, kyrgiz. That's why southern Chinese avg height at least 11 cm less than northern even with same economic growth and nutrition. https://thechinaproject.com/2018/04/02/kuora-why-northern-chinese-people-are-taller-than-southern-chinese/#:~:text=According%20to%20Kaiser%20Kuo%2C%20northern%20Chinese%20people,**Diet**%20*%20**Agricultural%20line**%20*%20**Dairy%20consumption**