In the present sample of Chinese immigrant women, positive life events were associated with greater energy intake, but migration-related stress was associated with lower overall gram intake, lower intake of grains, higher energy density, and a greater percent of energy from fat, especially among less acculturated women. These findings suggest that with exposure to migration-related stress, Chinese immigrant women eat less food but select foods that are higher in fat.
In previous studies, exposure to stress has been associated with both increased and decreased food intake (21
), increased snacking (25
), and shifts in food selection. Indeed, accumulating data suggest that, under conditions of stress, humans prefer highly palatable foods that are energy dense (21
) – in particular, increased consumption of high-fat, high-sugar foods (17
) and a reduction in main meals and vegetable consumption (19
). There may be both physiologic and behavioral reasons for such observations. For example, a preference for highly palatable, energy-dense foods has been attributed to hormones released during the stress response, such as cortisol (46
). Behaviorally, it has been proposed that individuals have less time and energy to devote to the preparation of foods during periods of stress; therefore, an increased reliance on pre-processed convenience foods, which are often energy dense, may also contribute to such findings (47
). Indeed, a study of eating behaviors among African Americans reported that stress was associated with haphazard meal planning (20
Our findings, based on detailed, quantitative dietary data from multiple 24-hour recalls, suggest that positive life events are associated with a general, overall increase in energy intake. Although this finding was somewhat unexpected, we speculate that the presence of positive events (e.g., parties, new job, gaining a new family member either through marriage or birth) is often accompanied by celebrations involving food. Negative life events were not associated with dietary factors in our sample, but migration-related stress appeared to decrease overall eating, as evidenced by its inverse association with total gram intake. It was also associated with higher energy density and percent of energy from fat, particularly among less acculturated women, and with a lower consumption of grains, suggesting a shift towards unhealthier dietary behaviors. That we observed an association of stress only with grains and not with other foods may be because grains were by far the most frequently consumed food group (32.8 servings/week), and its consumption may have been the most readily reduced in response to stress. Notably, we observed a suggestive inverse association of migration-related stress with intake of vegetables, the next most frequently consumed food group (23.1 servings/week), but this association did not reach statistical significance (β=−0.09, p=0.09, data not shown). Foods for which we might have expected to see some association, such as pastries and chips, were consumed by so few women in our sample that associations with these foods would have been difficult to detect.
Our findings on acculturative stress and dietary behaviors are similar to those reported in studies of mental health outcomes among Asian Americans, in which acculturative stress was a significant predictor of depression even after accounting for general perceived stress (16
). It may be that acculturative stress is experienced in a different manner than general stressors, perhaps because acculturative stress may pervade throughout all aspects of one’s identity and lifestyle (e.g., culturally, socially, and behaviorally). That migration-acculturation stress was more clearly associated with dietary outcome variables despite its correlation with negative life event impact score suggests the importance of assessing stressors specific to migration in immigrant populations and is an area that warrants further investigation.
A novel finding from our analysis is the possibility that level of acculturation moderates the association between stress and eating behavior. An association of migration-related stress with gram intake was more salient among less acculturated women than among their more acculturated counterparts, and an association with energy density was apparent only in less acculturated women. These associations suggest that with exposure to stress, less acculturated women did not increase their overall gram intake but rather selectively increased their relative intake of energy-dense foods. The associations are also contrary to our expectation that stronger associations would be apparent in the more acculturated women. The more acculturated women in our sample women appeared to have a more mainstream American dietary profile overall compared with less acculturated women, as evidenced by significant correlations of acculturation with energy density and percent of calories from fat of their diets, and an inverse correlation with intake of grains. This subtle dietary shift in more acculturated women may be masking associations of these dietary variables with stress in these women. The different eating behaviors that we observed in more vs. less acculturated women in our sample may also be relevant to the broad observation in other populations that less acculturated immigrants have better health status than their more acculturated counterparts (48
). Nevertheless, it should be pointed out that intake levels in the present sample overall (mean of 24% of energy from fat, 3.2 servings of vegetables a day excluding potatoes) are still substantially different from national norms (mean of 34% of energy from fat (50
), ~2.3 servings of vegetables a day excluding potatoes (51
)). Worth emphasizing is that participants in this study were a low-acculturation sample in general, and further changes in their eating habits and dietary responses to stress might be expected over time.
In our sample, more acculturated women reported more life events, suggesting the possibility of confounding. However, study analyses controlled for level of acculturation to minimize this as a concern. An additional limitation is that the sample was relatively homogenous with respect to age, and therefore, it is unknown whether the associations observed would differ among younger immigrant women who may be quicker to adopt American-style eating habits. Third, the cross-sectional nature of the data does not allow us to draw any inferences on the proposed direction of the association between stress and dietary intake. Fourth, although we used standard, multiple-pass procedures to minimize misreporting, underestimation of energy intake is common, and underreporters tend to report a higher percent of energy from protein (52
); thus, dietary measurement error may have diminished our ability to detect associations. Additionally, it is acknowledged that construct validity of the abridged, 11-item acculturation scale could not be more rigorously evaluated; in an ad hoc
evaluation of construct validity, the abridged scale was significantly correlated with length of residence (Pearson’s r=0.17, p=0.0004) and inversely correlated with age at migration (r=−0.14, p=0.004), and it was moderately and significantly correlated with a global indicator of American cultural orientation (‘Overall I am American’) (r=0.27, p<0.0001). Further, other variables that were not assessed in the present study, such as depression, may also influence dietary behaviors. Assessments to further distinguish the types of stressors experienced (e.g., ego-threatening, such as fear of criticism or failure, versus physical, such as illness or threat of attack) and types of eaters in the sample (e.g., restrained, emotion, or external) were also not available in the present study, and these may moderate associations with dietary response variables as reported in prior studies (19
Finally, the present study focused on a low acculturation sample of female Chinese immigrants, and therefore the generalizability of findings to men and other immigrant populations is unknown. However, a strength of the study is its inclusion of detailed measures of general life event stress and migration-specific stress as correlates of dietary intake in a natural (as opposed to laboratory-based) setting. The study is the first to specifically examine migration-related stress in relation to dietary intake in an immigrant sample. In addition, detailed, quantitative dietary data were collected to assess differences in dietary intake, rather than self-reported changes in selected aspects of the diet. As such, the present sample offers unique data from an understudied and highly informative population in transition, and thus, findings from this work can be used as the basis to extend this research to other recently immigrated populations.
Our findings suggest that the women in our sample decreased their overall gram intake with exposure to stress. Further, while both stress and acculturation have been independently studied in relation to changes in diet, this is one of the first studies to examine how acculturation may moderate the association between stress and dietary intake. Results indicate that associations of lower gram intake, higher energy density, and greater percent of energy from fat were more pronounced among less acculturated women in our sample. Our data add to the extant literature on how stress, and particularly migration-related stress, may be associated with overall health by affecting composition of food intake among immigrant populations. These findings contribute to a greater understanding of the nuanced and complex relations that may shape food choices and eating behaviors in a Chinese immigrant population, which could have implications for immigrants’ future health and risk for chronic diseases.