Shifting Educational Gradients in Body Mass Index Trajectories of Indonesians: An Age Period Cohort Analysis

Background: Globally, the number of obese adults has increased rapidly in many developing countries. The links between increased educational attainment and lower risks of overweight/obesity have been studied in a number of high-income contexts. However, educational attainment can have a different association with obesity at different levels of economic development and different stages of the nutritional transition, and these associations may vary by period and cohort. This study aims to provide evidence on the shifting of educational gradients in overweight/obesity in Indonesia, a low middle income country. Methods: Using five waves of Indonesian Family Life Survey (IFLS), this study examines the BMI trajectories of 14,810 individual from 1993 to 2014. This study analyses how educational gradients in BMI have shifted over time and across cohorts using a hierarchical age-period-cohort (HAPC) model to account for the effects of age and the changes in historical periods (social and environmental contexts). Results: In older generations, higher educational attainment was associated with higher BMI, but the gap between educational groups has shrunk in more recently-born cohorts. The BMI of lower educational groups is catching up with that of the tertiary educated, leading to an increased risk of overweight/obesity among low educated individuals. Having tertiary education lowers the risk of weight gain in women, but not in men. Conclusion: Changes in access to education and the ongoing nutritional transition in Indonesia are leading to a shifting of educational gradients in overweight/obesity over time. The rising trends in BMI among low-educated and younger individuals are of substantial concern for Indonesian public health due to their implications for the risk of non-communicable diseases in the future, and for communicable diseases during the covid-19 pandemic.