近日，华中农业大学经济管理学院李晓云教授团队发表了关于中国城乡转移居民食物消费与营养研究的研究成果，研究聚焦中国城乡转移居民，利用中国健康与营养调查（CHNS）数据，采用双向固定效应模型，探究社区都市化程度对中国城乡转移居民食物消费与营养摄取的影响，并分析了都市化程度对迁入城市中心的移民与迁入郊区的移民影响的异质性。
研究发现，城乡转移居民的食物消费与营养摄入显著地低于城市本地居民，且迁入城市中心的移民的营养摄入显著优于迁入郊区的移民。移民居住社区的都市化水平越高，其食物消费种类越多。
社区都市化程度对热量摄入的影响随着家庭人均收入的变化而变化。社区城市化水平和收入的边际效用分析发展，居住社区都市化水平提高没有显著增加低收入移民群体的热量摄入，却显著地增加了移民群体中收入较高人群的热量摄入。增加家庭人均收入无助于增加欠发达社区移民的热源摄入量。
研究也发现，来自蛋白质和脂肪的热量份额均与都市化程度存在显著的倒U型关系，这表明，都市化程度对热量摄入来源的改善作用不是持续的，当都市化指数达到66.69和54.26时，相应的蛋白质供热份额和脂肪供热份额达到最大。
研究结论指出在高度城市化地区，尤其是发达城市的较高收入移民群体，由于能量摄入过多而导致的超重和肥胖的营养过剩问题不容忽视；欠发达城市或郊区相对贫困迁移居民的营养改善问题应当从增加收入和改善社区条件两方面同时入手。该研究从城市发展的角度为改善城乡转移居民的营养状况，改善居民食物消费结构提供了决策依据。
审核人：李谷成
【英文摘要】
Purpose – The purpose of this paper is to examine the impact of urbanicity on rural–urban migrants' dietary diversity and nutrition intake and whether its effect differs across various urban environments of migrants.
Design/methodology/approach – Using the individual- and time-invariant fixed effects （two-way FE） model and five-year panel data from the China Health and Nutrition Survey （CHNS）， this paper estimates a linear and nonlinear relationship between urbanicity and nutrition. The paper also explores the spatial heterogeneity between rural–urban migrants and rural–suburban migrants. Dietary diversity, total energy intake and the shares of energy obtained from protein and fat, respectively, are used to measure rural–urban migrants' nutrition on both quality and quantity aspects.
Findings – The study shows that rural–urban migrants have experienced access to more diverse, convenient and prepared foods, and the food variety consumed is positively associated with community urbanicity. Energy intake is positively and significantly affected by community urbanicity, and it also varies with per capita household income. The obvious inverse U-shaped relationship reveals that improving community urbanicity promotes an increase in the shares of energy obtained from protein and fat at a decreasing rate, until reaching the urbanicity index threshold of 66.69 and 54.26, respectively.
Originality/value –This paper focuses on the nutritional status of rural–urban migrants, an important pillar for China's development, which is often neglected in the research. It examines the urbanicity and the nutrition of migrants in China, which provides a new perspective to understand the dietary and nutritional intake among migrants in the economic and social development. Moreover, the urbanicity index performs better at measuring urban feathers rather than the traditional rural/urban dichotomous classification.
论文链接：https://www.emerald.com/insight/content/doi/10.1108/CAER-02-2020-0016/full/pdf?title=urbanicity-and-nutrition-evidence-from-ruralurban-migrants-in-china
