Although research indicates foreign-born Mexican-Americans possess a healthy weight advantage relative to U.S.-born Mexican-Americans, patterns are less clear for children and may be changing over time. The objective of this study was 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. 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=4,718) and 2005-2014 (N=7,269), the investigators used log-binomial regression to calculate prevalence ratios (PR) of overweight/obesity by nativity status adjusting for age, sex, householder marital status, householder education, survey period and a nativity by survey period interaction. The investigators also tested another covariate-adjusted model with a 3-level ethnicity-nativity variable that included Whites and an ethnicity-nativity by survey period interaction.