Decomposition of Gender Differences in Body Mass Index in Saudi Arabia using Unconditional Quantile Regression: Analysis of National-Level Survey Data

Understanding gender differences in body mass index (BMI) between males and females has been much debated and received considerable attention. This study aims to decompose gender differentials in the BMI of people of the Kingdom of Saudi Arabia. The study decomposed the BMI gender gap into its associated factors across the entire BMI distribution by using counterfactual regression methods. The main method of analysis was newly developed unconditional quantile regression-based decomposition, which applied Blinder–Oaxaca decomposition using data from the Saudi Health Interview Survey. Gender differentials were found in the BMI, with females showing a higher BMI than males. The aggregate decomposition showed that both the covariate effect and the structural effect were significant at the 25th and 50th quantiles. Detailed decomposition indicated that income level and employment status as well as soda consumption and the consumption of red meat were significantly correlated in explaining gender differentials in BMI across various quantiles, but the magnitude varied by quantile. Our study suggests the government should consider introducing programs that specifically target women to help them reduce BMI. These programs could include organizing sporting events at the workplace and at the national level. Furthermore, the effect of soda consumption could be reduced by levying a tax on beverages, which might reduce the demand for soda due to the increased price.