Obesity Epidemiology

344 EPIDEMIOLOGIC STUDIES OF DETERMINANTS OF OBESITYthe National Institutes of Health (NIH) integrated disparities research into its strategicplan. Since then research investigating the social determinants of disparities in a range ofhealth conditions has increased considerably. While obesity has received comparativelyless attention, racial/ethnic variation in obesity has nevertheless been observed.The United States Census Bureau projects that by the year 2100, America will bemajority-minority, with non-Hispanic whites occupying only 40% of the U.S. population.At present however, obesity is disproportionately prevalent in several racial/ethnicminority populations, which becomes all the more concerning when one considers theexpected increase in the proportion of racial/ethnic minority groups in the U.S. populationin years to come.According to the 2000 U.S. Census, approximately 30% of the U.S. population belongsto a defined racial/ethnic minority group, which includes those who self-identify as blackor African American (those with origins in any of the black racial groups of Africa),Asian Americans (those with origins in the Far East, Southeast Asia, or the Indian subcontinent),American Indian or Alaska Native (those descended from the original peoplesof North, Central, and South America), native Hawaiian or Pacific Islander (those withorigins in any of the original peoples of Hawaii, Guam, Samoa, or other Pacific Islands),and Hispanic or Latino populations (those with Cuban, Mexican, Puerto Rican, South orCentral American, or other Spanish culture or origin). Individuals who self-identify asHispanic or Latino may be of any racial category, including white. In addition, beginningwith the 2000 U.S. Census, individuals were permitted to indicate two or more federallydesignated racial categories—such individuals are generally referred to as multiracial.The most recent data from the NHANES study show that in 2003-2004, the prevalenceof obesity among non-Hispanic blacks was 45%, compared to 37% among MexicanAmericans and 30% for non-Hispanic whites.Most studies generally agree that obesity is less prevalent among the Asian Americans,compared to whites and other U.S. racial/ethnic minority populations. Self-reported BMIdata from the National Health Interview Survey (NHIS) show, however, that there issizeable ethnic variation within the Asian population, such that BMI is highest amongJapanese and Filipino men and Filipino and Indian women (Vietnamese men and womenhave the lowest BMI among Asian Americans). As is discussed shortly, nativity is highlyrelated to obesity in the United States; the prevalence of obesity among Asian Americansis highest among those who are native-born. Among the foreign-born, obesity increasesproportionately with duration of residence. Very little data exists to capture accurately theobesity prevalence in native Hawaiian/Pacific Islander populations; however, the availableevidence suggests that the group has slightly higher obesity prevalence compared to non-Hispanic whites. 2Racial/ethnic disparities in obesity are particularly striking when examined by gender;presently, nearly 54% of black women are obese, and non-Hispanic black womenare more than twice as likely to be obese, compared to non-Hispanic white women.Compared to whites, the prevalence of obesity is higher among non-Hispanic blackand Hispanic men, 3 though most data indicate that the differences are not statisticallysignificant. 3-5 Indeed, this pattern of minimal (and not statistically significant) differencesin obesity between black and white U.S. men has persisted during most of the secondhalf of the 20th century. In contrast, odds of obesity are nearly twice as high amongblack and Hispanic women than among white women in most, 3-6 but not all, 7 studies.Numerous hypotheses have been offered to explain racial/ethnic differences in obesity.As a higher proportion of racial/ethnic minorities in the United States are of lowerSEP, some have argued that race/ethnicity might be a proxy for differences influenced bySEP. More recent evidence among U.S. blacks, showing limited SEP variation in obesity,