With the growing problem of childhood obesity, unhealthy dietary preferences among children have become an issue of worldwide concern. This article examines the class-peer effect of these preferences using random class assignment data from a field survey. The results show significant positive peer effects for both unhealthy food and beverages preference. These results remained robust after controlling for endogeneity issues using instrumental variables. Further analysis of the mechanism of peer effect shows that the better the relationship between classmates, the greater the influence peers have on unhealthy diet preferences among rural children. The same peer effect is found in situations where it is easy for children to obtain unhealthy food and beverages. The analysis of heterogeneity finds that the peer effects of unhealthy dietary preferences are stronger for girls, older students, and obese students. This paper also discusses the role of parents and schools in mitigating the peer effect. This paper proposes policy recommendations for rural areas in China to improve dietary preferences in children. These results may also provide useful guidelines for policy in other developing countries.

Improving physical, mental and cognitive health is a strategic choice to help developing countries cross the middle-income trap. This paper used data from the 2019 China Rural Children Health and Nutrition Survey (n = 826), and used the Ordered Probit (Oprobit), Logit and ordinary least squares (OLS) analytical methods to systematically analyze the implications of parental migration on multidimensional health. The results indicate that parental migration significantly harms the physical and mental health of rural children, and that mobile phone addiction has a significant moderating effect. Moreover, parental migration has a greater impact on the physical health, mental health and cognitive ability of boys and rural children with low family income, while parents with higher nutrition knowledge and education can effectively improve the physical health and cognitive ability of their children. In conclusion, in order to improve the multidimensional health of rural children, the government should strengthen the policy of care and support for children whose parents migrate. Schools and families should pay attention to the supervision of rural children’s mobile phone addiction.