Early-Life Nutrition and Subsequent International Migration: A Prospective Study in Rural Guatemala.

ABSTRACT

BACKGROUND: It is generally accepted that migrants are favorably self-selected for labor market skills such as higher schooling and greater cognitive capacity, which are highly correlated with early-life nutrition. However, the influence of early-life nutrition on later-life migration is understudied. OBJECTIVE: The objective of this study was to examine prospectively the association between height-for-age z scores (HAZ) at 24 mo and subsequent international migration in a cohort of 2392 participants born between 1962 and 1977 in 4 rural villages in eastern Guatemala. METHODS: Information on nutritional status and covariates was collected between 1969 and 1977 and migration status was determined as of 2017 (at ages 40-57 y). We used proportional hazards and logistic regression models to assess whether HAZ was associated with international migration, adjusting for early-life and adult characteristics. RESULTS: Between 1978 and 2017 there were 297 international migrants (12.4% of the original cohort) during 99,212 person-y of follow-up. In pooled models that were adjusted for early-life characteristics, a 1-SD increase in HAZ was associated with a 19% increase in the risk of international migration (HR 1.19; 95% CI 1.02, 1.38). Further adjustment for village characteristics did not alter the estimate substantively (HR 1.18; 95% CI 1.02, 1.37), while additional adjustment for schooling attainment attenuated the estimate somewhat (HR 1.14; 95% CI 0.98, 1.33). In all models, effect sizes were stronger for men than for women. CONCLUSIONS: Our results indicate that early-life nutrition is positively associated with subsequent international migration.