There are significant disparities among racial and ethnic groups in rates of obesity. Obesity has been rising more steeply among African American and Hispanic children than among children in other ethnic groups, explained Shiriki Kumanyika, professor of epidemiology in the Departments of Biostatistics and Epidemiology as well as Pediatrics (Section on Nutrition) and associate dean for health promotion and disease prevention at the University of Pennsylvania Perelman School of Medicine, in introducing a discussion of disparities and their implications for measurement. African American girls and Hispanic boys are particularly likely to have weight levels in the obese or very obese range, she added. Adult African American and Hispanic women both had high levels of obesity before the current epidemic began, and these levels have continued to increase with the epidemic in the general population. Obesity rates also are generally higher among populations of low socioeconomic status.
Health disparities are defined by the Centers for Disease Control and Prevention (CDC) as “differences in health outcomes that reflect social inequalities,” and CDC finds that such disparities are “both unacceptable and correctable” (CDC, 2011, p. 1). Thus, Kumanyika pointed out, “part of addressing the [obesity] epidemic has to include closing that gap.” To address the gap, she added, it is important to recognize that environmental, social, and cultural contexts for addressing obesity vary just as does its prevalence, and that solutions that will be effective within these different contexts also vary. Moreover, she noted, narrowing the gap will require attention to two goals: “one is to make everybody better off and the other is to help those who are worse off catch up.”
These issues present measurement challenges, Kumanyika observed. It is important to ask whether existing measures are sensitive enough “to pick up nuances or even big-picture issues that differ for population subgroups defined by ethnicity or socio-economic status,” she explained. Also important is to consider whether the measures focus on the right questions for each group, given potential differences in sociocultural contexts for food and physical activity.
Kumanyika also emphasized that disparities in obesity rates are not new. A 1985 report on the health of minority groups from the Department of Health and Human Services (HHS, 1985) identified obesity as one of the modifiable risk factors that could, if addressed, lead to a closing of the gap between white and minority populations in rates of cardiovascular disease and diabetes.
Some data Kumanyika presented illustrate how obesity prevalence and trajectories differ for ethnic minority compared with non-Hispanic white populations. Figure 7-1 shows changes in the population percentage at or above a body mass index (BMI) of 30 for African American, Mexican American, and white males and females between 1960 and 2004.