American children from ethnic minority and low socioeconomic families have higher rates of poor health and higher mortality rates. Recent data suggest persistence or widening of these ethnic and socioeconomic differentials in health outcomes of US children. For example, over the past three decades, overall, injury, and natural-cause mortality in childhood in the US declined. However, children from minority and lower socioeconomic position families experienced a smaller decline, resulting in a widening of the socioeconomic gap. The trends analysis for risk factors such as prevalence of obesity, prediabetes, and high blood pressure in US children also suggest similar persistence or increase of socioeconomic and ethnic disparities. Adverse health risk behaviors that include diet are among the many factors such as access to health care, environmental exposures, neighborhood contexts, income constraints, and discrimination that may contribute to ethnic and socioeconomic disparities in the health of US children. The hypothesis that diet may be a mediator of ethnic and socioeconomic disparities in health appears reasonable given that diet is an acknowledged risk factor for a number of chronic diseases. However, surprisingly little is known about the independent associations of ethnicity and measures of socioeconomic position-- family income, education, and occupation--with dietary attributes within a multivariate framework in US children. Also, there is no published information on how the association of diet and socioeconomic position may be changing over time in US children. Assessment of time trends in dietary disparities due to ethnic and socioeconomic group membership may help us to understand whether diet may be a contributor to persistence or increase of health disparities among US children. Therefore, the overall objectives of this application are to examine in US children and adolescents: 1) the independent associations of race/ethnicity and measures of socioeconomic position (family income, education, and occupation) with attributes of reported diets and objective biomarkers of dietary intake, and 2) the trends in the association of race/ethnicity and socioeconomic position with diet quality from 1971 to 2006. We will use nationally representative data for 2-19 year olds (n= 39,607) from the National Health and Nutrition Examination Surveys (NHANES) conducted in1971-74, 1976-1980, 1982-1984 (Hispanic HANES), 1988-1994, an 2001-2006, to address these issues. PUBLIC HEALTH RELEVANCE: The importance of dietary factors in improving health outcomes is underscored by the fact that dietary factors are amenable to intervention, and diet is universally consumed and even a small relative risk may have a considerable public health impact. Assessment of time trends in ethnic and socio- economic differentials in diet quality will therefore help in determining the absolute as well as relative progress in closing the ethnic and socioeconomic gaps in health outcomes that is a stated goal of the national health promotion agenda. The results of this study will thus help in evaluating the effectiveness of past efforts to promote desirable behavior changes in these high risk populations, and design of newer strategies to target dietary attributes associated with ethnicity and socioeconomic position.