Obesity inequality in Malaysia: decomposing differences by gender and ethnicity using quantile regression

Abstract

Objective. Obesity prevalence is unequally distributed across gender and ethnic group in Malaysia. In this paper, we examine the role of socioeconomic inequality in explaining these disparities.

Design. The body mass index (BMI) distributions of Malays and Chinese, the two largest ethnic groups in Malaysia, are estimated through the use of quantile regression. The differences in the BMI distributions are then decomposed into two parts: attributable to differences in socioeconomic endowments and attributable to differences in responses to endowments.

Results. For both males and females, the BMI distribution of Malays is shifted toward the right of the distribution of Chinese, i.e., Malays exhibit higher obesity rates. In the lower 75% of the distribution, differences in socioeconomic endowments explain none of this difference. At the 90th percentile, differences in socioeconomic endowments account for no more than 30% of the difference in BMI between ethnic groups.

Conclusions. Our results demonstrate that the higher levels of income and education that accrue with economic development will likely not eliminate obesity inequality. This leads us to conclude that reduction of obesity inequality, as well the overall level of obesity, requires increased efforts to alter the lifestyle behaviors of Malaysians.

Keywords:

• obesity
• Malaysia
• health disparities
• quantile regression
• decomposition

Notes

1. US$1.00=RM3.58; RM1.00=US$0.28 (approximately as of 11 December 2008).

2. Unfortunately, the data from previous survey efforts, such as the Second National Health and Morbidity Survey from 2006, have not been preserved.

3. However, these estimates do not include other indirect costs such as lower productivity, consumer spending on weight-reduction products and services as well as implicit socioeconomic hardship due to a higher rate of disability, worsening quality of life in terms of poor self-image, social ostracism, early retirement and deaths, and widespread discrimination due to overweightness or obesity (Witkowski 2007).