Can racial disparity in health between black and white Americans be attributed to racial disparities in body weight and socioeconomic status?

Little is known about racial differences in chronic health conditions (CHCs) among older adults. Even less is known about whether the rate of change in CHCs varies by race or ethnicity (hereafter "race"). It is estimated that more than half of U.S. adults are overweight or obese (National Task Force on the Prevention and Treatment of Obesity, 2000). This figure is alarming given that body weight is associated with health (U.S. Department of Health and Human Services, 2001). Specifically, obesity (body mass index [BMI] > 30) has been found to be associated with health risks such as occurrence of diseases and functional limitations (World Health Organization, 1997). Mokdad et al. (2003) showed that the prevalence of obesity among U.S. adults continues to increase with time and that obesity is significantly related to diabetes, high blood pressure, high cholesterol, asthma, and arthritis. In a similar vein, Visscher and Seidell (2001) found that obese people are more vulnerable to diseases like cardiovascular disease, diabetes, cancer, and respiratory disorders, which are critically related to functional disabilities as well as mortality rates (Calle, Thun, Petrelli, Rodriguez, & Heath, 1999). Although there are not many studies in this area focused on older adults, the available literature supports the notion that obesity is closely related to older adults' negative health status. For example, Himes (2000) found that obesity is associated not only with a higher probability of having arthritis, diabetes, and hypertension, but also with a greater likelihood of experiencing functional limitations among individuals 70 and over. In summary, the literature shows that the negative consequences of obesity encompass increased risks of disease, which are accompanied by increased health care costs, lowered productivity, and increased mortality (Nestle & Jacobson, 2000; U.S. Department of Health and Human Services, 2001). Race is associated with both CHCs and BMI (Kahng, Dunkle, & Jackson, 2004; Mokdad et al., 2003; U.S. Department of Health and Human Services, 2001; Wilkinson & Pickett, 2006), indicating that disadvantaged ethnic minorities (for example, black Americans) present higher BMIs and more CHCs. For example, Robert and House (1996) found that black Americans present more CHCs than their white counterparts. Including adults age 70 and over in the sample, Himes (2000) found that black American elders were more likely to be overweight or obese. Specifically, between 1988 and 1994, about 64 percent of non-Hispanic black Americans were overweight or obese compared with about 55 percent of non-Hispanic white Americans (U.S. Department of Health and Hunlan Services, 2001). In 2002, about 69.3 percent of non-Hispanic black Americans were overweight or obese, whereas about 57.4 percent of nonHispanic white Americans were overweight or obese (U.S. Department of Health and Human Services, 2004). To address racial disparities in body weights and health more effectively, examination of the relationships between race, BMI, and CHCs is necessary as these relationships can provide empirical evidence to guide the directions for prevention and treatment of racial disparities in health. Regardless of previous research suggesting that race is associated with both BMI and health conditions (for example, Himes, 2000; Robert & House, 1996; U.S. Department of Health and Human Services, 2001), little is known about cross-sectional or longitudinal mechanisms that tie together race, BMI, and CHCs. Specifically, it is not known whether racial disparities in health conditions and their changes are attributable to racial differences in BMI. Even less is known about whether the relationships between BMI and CHCs vary by socioeconomic status (SES). In addition to body weight and race, sociodemographic characteristics such as age, gender, and SES are associated with health (Mackenbach et al., 2008; Peek & Coward, 2000). …