Understanding the role of inequality of opportunity in body mass index and waist circumference among Mexican adults

Mexico faces one of the most acute obesity crises worldwide. Despite policy efforts to decrease the prevalence of obesity among adults, an upward trend continues. The aetiology of obesity is complex and defined by multiple factors. While most of the literature has centered on studying behavioural attitudes that contribute to an energy balance that is positive (e.g., when energy intake is greater than expenditure), fewer studies have explored the role of inequality of opportunity (IOp), which focuses on studying the pathways from people's circumstances to health outcomes. In this study, IOp is measured, identified, and characterised in body mass index and waist circumference for Mexican adults. To address the challenges related to measuring IOp in these health outcomes, a modified version of the dissimilarity index and unconditional quantile regression models based on recentered influence functions are used. Results show that variation in both outcomes is related to inequality in circumstances. The two main drivers of these inequalities are parental health conditions and the geographic region where individuals live. These findings offer a broader perspective to the role of people's circumstances and their importance in tackling the obesity crisis in Mexico.