标题：Immigration and Generational Trends in Body Mass Index and Obesity in the United States: Results of the National Latino and Asian American Survey, 2002–2003
摘要：Objectives. We examined patterns of body mass index (BMI) and obesity among a nationally representative sample of first-, second-, and third-generation Latinos and Asian Americans to reveal associations with nativity or country of origin. Methods. We used data from the National Latino and Asian American Survey (2002–2003) to generate nationally representative estimates of mean BMI and obesity prevalence and explored changes in the distribution of BMI by generational status. Analyses tested the association between generational status and BMI and examined whether this association varied by ethnicity, education, or gender. Results. We found substantial heterogeneity in BMI and obesity by country of origin and an increase in BMI in later generations among most subgroups. The data suggest different patterns for Latinos and Asian Americans in the nature and degree of distributional changes in BMI with generational status in the United States. Conclusions. Generational status is associated with increased BMI and obesity among Latinos and Asian Americans. Aggregate estimates not accounting for nativity and country of origin may mask significant heterogeneity in the prevalence of obesity and patterns of distributional change, with implications for prevention strategies. Obesity is widely recognized as a significant and growing health problem in the United States. 1 – 9 Although racial/ethnic variation in obesity and obesity-related morbidity and mortality has been observed in several studies, 5 , 10 , 11 data on racial/ethnic patterns in obesity and body mass index (BMI) in the United States are limited. For example, the National Health and Nutrition Examination Survey, the primary data source for monitoring national prevalence trends in the United States, only reports results for non-Hispanic Whites, non-Hispanic Blacks, and Mexican Americans. In particular, there is a relative dearth of data on BMI and obesity among Asian Americans, overall and by national origin subgroup. 12 – 14 Analyses that also take nativity into account are even rarer; only a handful of studies report indicators of adiposity by time in the United States. 12 , 15 – 20 All but 3 of these investigations used the same data source (the National Health Interview Survey). 15 , 16 , 18 These studies typically found lower levels of obesity among first-generation immigrants than among subsequent generations and higher obesity with longer US residence among the foreign born. Several considerations motivated our examination of patterns of BMI and obesity by generation. As with other health outcomes, aggregate prevalence estimates may mask important heterogeneity. In particular, populations with high proportions of foreign-born individuals (such as many groups of Asian origin or descent) may have relatively low rates of morbidity and mortality that are driven largely by their preponderance of healthy immigrants 12 and may be likely to change as the generational distribution of the population evolves. Moreover, immigrants and their US-born offspring are a rapidly increasing proportion of the total US population. Understanding the patterning of obesity by nativity is important for forecasting trends in prevalence and related morbidity and for identifying vulnerable populations for intervention. It can also elucidate etiologic processes related to changes in the physical, social, economic, and normative environment that influence patterns of obesity. To improve understanding of the distribution of BMI and obesity by ethnicity and generational status in the United States, we used data from the National Latino and Asian American Survey to generate nationally representative estimates of mean BMI and prevalence of obesity for Latino and Asian American adults overall and by subgroups defined by place of origin or ancestry, education (as a measure of socioeconomic position), and gender. We especially focused on how patterns of BMI distribution and obesity vary by generation among these groups, comparing first-, second-, and third-generation Latinos and Asian Americans.
