Does the immigrant advantage in overweight/obesity persist over time in Mexican-American youth? NHANES 1988–1994 to 2005–2014

OBJECTIVES: To examine whether the relationship between nativity and overweight/obesity has changed over time among Mexican-American children and to investigate the implications of this pattern on overweight/obesity disparities relative to non-Hispanic Whites. METHODS: Using cross-sectional data from Mexican-Americans and non-Hispanic white children ages 4–17 years participating in the National Health and Nutrition Examination Surveys (1988–1994 (N=4,720) and 2005–2014 (N=7,275), we used log-binomial regression to calculate prevalence ratios (PR) of overweight/obesity by nativity status adjusting for sociodemographic covariates, survey period and a nativity by survey period interaction. In a separate covariate-adjusted model, we also tested a 3-level ethnicity-nativity by survey period interaction that included non-Hispanic Whites. RESULTS: In 1988–1994, foreign-born Mexican-Americans had significantly lower prevalence of overweight/obesity compared to U.S.-born Mexican-Americans (PR=0.75, 95% CI: 0.61, 0.94). However, by 2005–2014, the nativity gap in overweight/obesity closed (PR=0.94; 95% CI: 0.84, 1.07). Moreover, while foreign-born Mexican-Americans had the lowest levels of overweight/obesity in 1988–1994, by 2005–2014, foreign-born and U.S.-born Mexican-Americans had comparable estimates, both significantly higher than that of non-Hispanic Whites. CONCLUSIONS: Although overweight/obesity disparities between Mexican-Americans and non-Hispanic Whites had previously been specific to U.S.-born Mexican-Americans, disparities in recent years have extended to foreign-born Mexican-Americans.