Explaining Gender-Specific Racial Differences in Obesity Using Self-Reports of Food Intake and Physical Activity

Frank Heiland, Baruch College, City University of New York (CUNY)
Mary A. Burke, Federal Reserve Bank of Boston

In NHANES data (waves 1999–2006), we initially observe a very weak relationship between self-reported measures of caloric intake and physical activity and either BMI or obesity risk, and these behaviors appear to explain only a small fraction of the black-white BMI (or obesity) gap among women. Using an innovative method to mitigate the widely recognized problem of measurement error in self-reported behaviors—proxying for measurement error using the ratio of reported caloric intake to estimated caloric expenditure—we obtain much stronger relationships between behaviors and BMI (or obesity risk). We find that the combination of lower physical activity levels and higher caloric intakes among black women compared to white women accounts for almost half of the difference in mean BMI between these groups and accounts for nearly two-thirds of black women’s excess obesity risk. Observed behaviors among men are consistent with the presence of much smaller BMI/obesity gaps between blacks and whites.