This is particularly concerning for public health authorities in China, a country that has seen large-scale rural-to-urban migration as Chinese workers seek out opportunities to better their lives. However, associations between urban living and overweight and obesity have not been well-studied in China.
To redress this gap, Professor Guang-Liang Shan from Peking Union Medical College, China, and his colleagues sought to understand the impact of rural-to-urban migration on overweight and obesity in the Yi people, an ethnic minority group hailing from remote mountainous areas in southwest China. They hypothesized that Yi rural-to-urban migrants may be at risk of becoming overweight or obese, with age at migration and duration of migration (i.e., time spent living in an urban environment) influencing the magnitude of such risks. To test this hypothesis, the researchers analyzed data from 1,162 Yi rural-to-urban migrants and 1,894 Yi farmers from the Liangshan Yi Autonomous Prefecture in Sichuan province using sophisticated statistical models. The results of their analyses appear in a paper published in Chinese Medical Journal on 20 August, 2020.
Compared with non-migrant Yi farmers, migrants had higher body mass index values and were 2.13 times more likely to be overweight or obese. For migrants who were 20 years or younger upon arrival, the risk of becoming overweight or obese did not increase with time spent in the urban environment. Conversely, for migrants who were more than 20 years old at the time of migration, long-term stay of more than 30 years in the urban area, reflected increased risks of becoming overweight or obese.
Prof. Shan explains thus: “Yi migrants with longer urban residence times were better educated and had higher personal incomes, which means that they were less likely to work at jobs that required extensive physical labor and more likely to have access to high-fat and energy-dense foods. On the other hand, migration at a young age possibly implies better access to education, and better education may lead to increased awareness of how to lead a healthier life.”
The findings underscore the need for awareness programs to educate rural-to-urban migrants on adopting healthy lifestyles in urban areas to minimize health risks.