More than one-third of the US population is obese. Access to health care and insurance coverage among obese individuals will inform ways to address the obesity epidemic. We examined the impact of Medicaid expansion under the Affordable Care Act (ACA) on health insurance coverage among obese individuals, as compared to non-obese individuals.


Date were obtained from the 2006-2017 Behavioral Risk Factor Surveillance System. The study sample included 5,066,370 non-institutionalized, non-pregnant adults aged 18-64 years. We conducted a difference-in-difference analysis to compare the insurance coverage rates among obese and non-obese individuals in Medicaid-expanded states and those in non-Medicaid expanded states, before and after some states expanded Medicaid in 2014, 2015 and 2016. We adjusted for age group, sex, race/ethnicity, educational attainment, household income, employment status, marital status and general health status in the logistic regression models. We applied sampling weights in all analyses.


Nine percent had some form of insurance, and 32.8% were obese. We found that insurance coverage rates increased among both obese and non-obese individuals during the period from 2014 to 2017, as compared to the period from 2006 to 2013. Medicaid expansion increased insurance coverage rate by 1.1% (95% CI: 0.4%-1.9%) for obese individuals, and by 1.2% (95% CI: 0.6%-1.7%) for non-obese individuals.


Medicaid expansion under ACA can improve access to care for people with obesity. The fact that the coverage improvement in both obese and non-obese individuals are comparable suggests that adverse selection due to weight status may not be a concern.