To investigate the socioeconomic inequality of obesity and its determinants in Iran.Methods:
Data was from Iran's surveillance system for risk factors of non-communicable diseases which was conducted on 89,400 individuals aged 15–64 years in 2005. Principal component analysis was used to create a new variable for defining socioeconomic status of participants. We assessed inequality by calculating a slop index of inequality and concentration index for obesity. Oaxaca-Blinder decomposition analysis was used to determine the determinants of inequality.Results:
The slop index of inequality and concentration index for obesity was −13.1 (95% Confidence Intervals [CI]: −16.3 to −9.8) percentage points and −0.123, respectively. The level of inequality varied widely between different provinces in Iran and was more severe in women and urban population. Obesity persisted in 20.2% (95% CI: 19.4–20.9) of the low-socioeconomic group and 11.0% (95% CI: 10.5–11.6) of the high-socioeconomic group. More than 90% of this gap was due to differences of independent variables (mainly age, gender and marital status) in two socioeconomic status groups.Conclusions:
A pro-rich inequality existed in the obesity in Iran. Older age, female gender and rural residency contributed most to the economic inequality of obesity.