Our study of a population-based sample of Asian Americans in California found that acculturation categories based on nativity and language were independently associated with overweight/obesity and that bicultural Asian Americans, despite an education and income profile similar to that of acculturated Asian Americans, had rates of overweight/obesity similar to those found among traditional Asians. While our study is consistent with prior studies indicating that US-born Asian Americans are more likely to be overweight/obese than foreign-born Asian Americans, our results add to this literature by suggesting that cultural orientation, rather than simply birth and life in the US environment, may influence obesity rates.
Analysis of Asian Americans by both acculturation status and generational status each revealed unique insights into mechanisms contributing to overweight/obesity. We found that the bicultural group had a low percentage of overweight/obesity compared to the acculturated group, which suggests that loss of heritage culture rather than gain of host culture is a key factor in development of overweight/obesity, particularly for women. Furthermore, we found that third or higher generation respondents (almost all of whom were acculturated) had higher percentages of overweight/obesity than acculturated respondents overall. This suggests a synergistic influence between increasing generational status and the loss of heritage orientation on overweight/obesity, perhaps due to a set of broader cultural changes in behaviors that are associated with generational status.
Some of the cultural changes that may lead to overweight/obesity are manifest in respondents’ reports of physical activity and consumption of fries and soda. Unhealthy consumption of fries and soda increased with acculturation, consistent with US norms. Interestingly, physical activity increased with acculturation as well, which is consistent with a study that reported that US-born Asians have increased leisure-time physical activity compared to foreign born Asians Americans [
22]. In our study, neither diet nor exercise patterns strongly explained the association between acculturation and overweight/obesity. This surprising result may be because the measures of diet and exercise in this dataset did not truly capture more subtle differences in diet and exercise behavior, and consequently were weak proxies for real-life behavior. Thus, the effects of cultural change on obesity are likely mediated by a broader set of behaviors or factors not captured by our study.
Also left to explain is the suggestion that acculturation may have higher impact on women than on men with respect to overweight/obesity, or that biculturalism may be more protective in women than in men. Gendered cultural norms and values could certainly play a role in the differential effect of acculturation on each gender. Further exploration of the impact of gender on acculturation may be an avenue of additional research.
Other studies have found a protective role of biculturalism in child and adolescent mental health and social functioning. Recent studies of acculturation among children and adolescents of first generation immigrants of many ethnicities, including Hispanic and Asian, link fluent bilingualism in English and heritage language with higher academic achievement, higher educational and occupational ambitions, higher self esteem and decreased depression [
11]. Involvement of Latino teens in parental culture of origin was found to be positively related to self esteem [
23]. Fluent bilingualism in children of immigrants is associated with
“selective acculturation[,which] takes place when the learning process of both generations is embedded in a co-ethnic community of sufficient size and institutional diversity to slow down the cultural shift and promote partial retention of the parents’ home language and norms” [
11]. Our study appears to extend the benefits of biculturalism and selective acculturation beyond children and adolescents and to the realm of physical health, at least among Asian Americans. This may differ in other ethnic groups. Studies of Latino immigrants have noted that although obesity tends to increase with increasing generations and duration of residence in the US, among Latina women, English preference [
18,
24] or higher levels of assimilation [
25] is actually associated with lower obesity, suggesting a protective effect conferred by acquisition of host culture. Differences in obesity patterns between ethnic groups may be partly explained by segmented assimilation to diverse subcultures and communities within the US.
Our study has several limitations. The study was conducted on a California population sample and may not generalize to Asian Americans elsewhere. We relied on respondents’ self report of weight and height and health behaviors, which is subject to recall error and bias. Social desirability leading to underreporting of weight may differ by acculturation status, potentially leading to conservative differences in obesity rates. We had no direct measure of acculturation and included language ability as a proxy, as is commonly done. As a result of using proxy measures for acculturation, some misclassification of acculturation status remains a possibility. We also had no measure of parity, which contributes to obesity in women. Sample size limitations did not allow for complete analysis of individual Asian ethnic groups, and our results may not extend to other Asian groups with different cultural and religious practices such as Japanese, Filipino, or South Asian. Finally, a cross-sectional study cannot prove a causal link between acculturation and development of obesity, although reverse causation is unlikely in this case.