A Comparison of Two Models Examining the Relationship Between Psychological Distress, Health Behaviors and Weight Status Across Mexican and White Chicago Residents.

Authors: Concha, J.B., Whitman, S., Johnson, T., Kravitz, H. Chavez, N., Kelley, M., & Chin, M.

Background:
Mexican-Americans in the U.S. are at risk for obesity and several behavioral factors such as eating high fat foods and a sedentary lifestyle have been identified as major contributors for obesity; however, few studies have examined the influence of psychological distress on such behaviors and weight status. Because many Mexican-Americans live in socially stressful environments that do not support healthy behaviors, the objective of this study is to examine both the direct and indirect relationships between sociocultural determinants, psychological distress, health behaviors, and body mass index (BMI) for both Mexican and white individuals.

Methods:
Separate path analyses were conducted for each group of Mexican (n=363) and white (327) respondents in a health survey. The independent variables included in each path analysis included gender, income, educational attainment, years in the U.S., perceived stress, depressive symptoms, discrimination. The dependent variables included healthy and unhealthy food intake, physical activity, and BMI.

Results:
Mexican respondents reported significantly higher levels of perceived stress (M=5.04 vs. M=3.98, p=.000), depressive symptoms (M=2.48 vs. M= 1.75, p=.000), and discrimination (M=16.04 vs. M=13.77, p=.000) when compared to the white respondents. The Mexican respondents further reported less physical activity, the intake of fewer healthy foods and a significantly higher mean BMI (M= 28.96 vs. M=26.29, p=.000). The path analysis revealed two distinct path models with depressive symptoms being the variables best explained in both the Mexican (X_=16.13, df=10, p=.097, CFI=.94) and white (X_=25.58, df=17, p=.082, CFI=.95) group path models. The Mexican group path model revealed that time in the U.S. was positively associated with perceived stress (_=.05, p<.05) and BMI (_ =.10, p<.001). Depressive symptoms was directly associated with unhealthy food intake (_=.12, p<.05) and mediated by perceived stress. Education was inversely associated with depressive symptoms (_=-.25, p<.01), perceived stress (_=-.27, p<.01), and BMI (_=-.45, p<.05). The path model for the white group revealed that time in the U.S. was positively associated with BMI (_=.17, p<.01) and inversely associated with perceived stress (_=-.04, p<.001) and discrimination (_=-.06, p<.001). Income was inversely associated with perceived stress (_=-.38, p<.01), which in turn was related to increased BMI (_=.41, p<.01). Depressive symptoms was inversely related to physical activity (_=-.15, p<.02) and mediated by perceived stress (_=.43, p<.001).

Conclusions:
While depressive symptoms were not associated with BMI in the Mexican group path model it was significantly associated with weight related behaviors. The model also suggests that some aspect of acculturation via time in the U.S. increases perceived stress and indirectly influences unhealthy food intake. The white group path model however did reveal that perceived stress was associated with BMI. The path models also reveal that education may act as a protective factor for psychological distress and weight gain in Mexican individuals, whereas income may be more of a risk factor toward experiencing psychological distress in white individuals.