Pierre Levasseur

How delayed school enrollment reduces overweight but increases stunting in developing countries. Evidence from Brazil

Abstract: Nutritional status and educational performance are known to be closely linked. However, although recent studies found that the age of primary school enrollment is a major driver of educational achievement and adult income, its impacts on childhood health and nutrition remain largely unknown, particularly in emerging countries where childhood stunting and overweight coexist. In Brazil, children are supposed to enroll in primary school the year they turn six. Using a recent representative database of middle and high school students in Brazil based on a survey conducted in 2015, I implement an instrumental variables strategy using exogenous variations in the students’ birthdate to isolate the impact of late enrollment in primary school (i.e. older than 6 when enrolled) on height-for-age and body mass-for-age indicators. Overall, late enrollment has a protective effect against hazardous weight gain, reducing the prevalence of overweight (-3 percentage points). However, late-enrolled students from under-privileged families had lower height-for-age scores than their younger counterparts (-0.6 z-score unit). Transmission mechanisms are discussed and partially tested. The findings highlight the importance of providing free school meals for students from underprivileged families to reduce stunting, while simultaneously countering negative school externalities such as bullying to fight the epidemic of childhood obesity.

Key words: Brazil; schooling; childhood overweight; height-for-age; BMI-for-age.