Socioeconomic inequalities in adult obesity risk in Canada: trends and decomposition analyses

This study examines trends in socioeconomic-related inequalities in obesity risk among Canadian adults (aged 18-65 years) from 2000 to 2010 using five nationally representative Canadian Community Health Surveys (CCHSs). We employed the concentration index (C) to quantify the socioeconomic inequalities in obesity risk across different demographic groups and geographic regions in each survey period. A decomposition analysis of inequality is performed to determine factors that lie behind income-related inequality in obesity risk. Although declining over time, the results show that there exists income-related inequality in obesity risk in Canada. The estimated Cs for men indicate that obesity is concentrated among the rich and its trend is increasing over time. The findings, however, suggest that obesity is more prevalent among economically disadvantaged women. While we found that obesity is mainly concentrated among the poor in the Atlantic Provinces, the degree of socioeconomic related inequality in obesity risk is increasing in these provinces. The results for Alberta showed that obesity is concentrated among the better-off individuals. The decomposition analysis suggests that factors such as demographics, income, immigration, education, drinking habits, and physical activity are the key factors explaining income-related inequality in obesity risk in Canada. Our empirical findings suggest that, in order to combat the obesity epidemic, health policies should focus on poorer females and economically well-off males.