标题：Race, Place, and Obesity: The Complex Relationships Among Community Racial/Ethnic Composition, Individual Race/Ethnicity, and Obesity in the United States
摘要：Objectives. We explored the association between community racial/ethnic composition and obesity risk. Methods. In this cross-sectional study, we used nationally representative data from the Medical Expenditure Panel Survey linked to geographic data from the US Decennial Census and Census Business Pattern data. Results. Living in communities with a high Hispanic concentration (≥ 25%) was associated with a 0.55 and 0.42 increase in body mass index (BMI; defined as weight in kilograms divided by the square of height in meters) and 21% and 23% higher odds for obesity for Hispanics and non-Hispanic Whites, respectively. Living in a community with a high non-Hispanic Asian concentration (≥ 25%) was associated with a 0.68 decrease in BMI and 28% lower odds for obesity for non-Hispanic Whites. We controlled for individual- and community-level social, economic, and demographic variables. Conclusions. Community racial/ethnic composition is an important correlate of obesity risk, but the relationship differs greatly by individual race/ethnicity. To better understand the obesity epidemic and related racial/ethnic disparities, more must be learned about community-level risk factors, especially how built environment and social norms operate within communities and across racial/ethnic groups. The prevalence of obesity has risen significantly over the past few decades and is now considered one of the most pressing public health problems in the United States. 1–5 Currently, more than one third of adults older than 20 years are obese, defined as having a body mass index (BMI; defined as weight in kilograms divided by the square of height in meters) of 30 or more. 2 Obesity and sedentary lifestyle are risk factors for a variety of chronic conditions and are leading causes of premature mortality and years of life lost. 6–9 Various estimates put the number of deaths attributable to obesity in the United States between 112 000 and 300 000, second only to cigarette smoking. 10–12 Members of the current US generation may have a shorter life expectancy than their parents if the obesity epidemic continues. 13–16 There are large financial costs associated with obesity, too. 17 For example, a recent study found that the annual medical burden of obesity and overweight is nearly 10% of total medical spending, or $147 billion in 2008. 18 The US obesity epidemic has disproportionately affected certain racial and ethnic minority groups. 2,5,19 For example, approximately 50% of African American women are obese compared with only 33% of White women. 2 Individual factors such as income and education explain some of the observed racial/ethnic differences in obesity, but wide differences persist even after a large number of individual characteristics are held constant. 20 Recent research suggests that community-level characteristics such as the availability and accessibility of sidewalks, parks, and recreational facilities 21–26 and food selection and cost 27–30 are related to obesity independent of individual characteristics. Thus, one line of research documents wide racial/ethnic disparities in the risk of obesity at the individual level, whereas another identifies several community characteristics that are associated with both the risk of obesity and related racial/ethnic disparities. There is a gap between these 2 lines of research; little is known about how the racial and ethnic composition of residential communities is associated with individual-level obesity risk and how this association might differ by individual-level race/ethnicity. Investigating community-level racial/ethnic composition as a risk factor for obesity, above and beyond individuals’ own characteristics, will help improve understanding of racial/ethnic disparities in health, and guide future interventions to eliminate health disparities, which is a national priority. 31 Although little empirical evidence exists on the possible relationship between community racial/ethnic composition and obesity, there is reason to hypothesize that a relationship might exist. Social norms regarding body weight may differ significantly across ethnic groups. For example, perceived ideal body size for non-Hispanic Black women is larger than for non-Hispanic White women, and non-Hispanic White women report dissatisfaction with their bodies at significantly lower weights than do non-Hispanic Black women. 32 Furthermore, non-Hispanic Black men report a preference for larger body sizes in female partners than do non-Hispanic White men. 33 Given that obesity rates and norms regarding body weight differ across racial and ethnic groups and, at the same time, the United States is highly segregated along racial and ethnic lines, it is plausible that norms regarding body weight could develop at the community level. This, in turn, may give rise to an association between community-level racial/ethnic composition and the risk of obesity independent of the characteristics of individuals. This study addresses 2 main questions. First, is the racial/ethnic composition of communities associated with obesity beyond what would be expected given the characteristics of the individuals? Second, if an association exists, does it differ on the basis of an individual’s own racial/ethnic identity? Our findings will enhance understanding of disparities in the US obesity epidemic, and the mechanisms by which certain racial/ethnic minorities are disproportionately affected.
