Obesity prevalence in the United States has increased drastically in the last two decades. Racial differences in obesity have emerged with the increase in obesity, with temporal trends because of individual, socioeconomic, and environmental factors, eating behaviors, lack of exercise, etc., raising questions about understanding the mechanisms driving these racial differences in the prevalence of obesity among non-Hispanic Black (NHB) and non-Hispanic White (NHW) men. Although many studies have measured obesity using body mass index (BMI), little is known about waist circumference (WC). This study examines variations in obesity among NHW and NHB using BMI and WC. We used National Health and Nutrition Examination Surveys (1999-2016) with a sample of 9,000 NHW and 3,913 NHB men aged 20 years or older. To estimate the association between the prevalence of obesity (BMI ≥30) and race, we applied modified Poisson regression; to explore and decompose racial differences, we used Oaxaca-Blinder decomposition (OBD). We found that NHW had higher abdominal obesity (WC ≥102) than NHB, but NHB were more likely to be obese (BMI ≥30) during most years, with some fluctuations. Modified Poisson regression showed that NHB had a higher prevalence of obesity (prevalence ratio [PR]: 1.11, 95% confidence interval [CI] = [1.04, 1.18]) but lower abdominal obesity (PR: 0.845; 95% CI = [0.801, 0.892]) than NHW. OBD showed that age, access to health care, smoking, and drinking contributed to the differences in abdominal obesity. The study identifies a significant increase in obesity among men over the last two decades; generalized obesity (based on BMI) was more problematic for NHB men, but abdominal obesity was more problematic for NHW men.
Keywords: Oaxaca–Blinder decomposition; body mass index; men; race; waist circumference.