Abstract
Recent survey data reveal the persistence of long-acknowledged socioeconomic status (SES) differentials in the prevalence of obesity in U.S. children and adolescents. We examined 30-y changes in the association of dietary and meal behaviors with family income and education to understand the possible contribution of these trends to SES trends in obesity rates in 2- to 19-y-old Americans. We used dietary and SES data for 2- to 19-y olds from the NHANES 1971-1974 to 2003-2008 (n = 39,822). The secular changes in the independent association of family income and education with 24-h dietary behaviors [energy intake (kcal), amount of foods and beverages (g), percent energy from all beverages and from nutritive beverages, and energy density of foods] and 24-h meal behaviors [number of eating occasions, energy from snack episodes (%), and mention of breakfast] were examined using multivariable regression methods. The secular increase in energy intake and food and beverage amount was significant in the lowest family SES categories. The positive association of family income and education with intakes of energy, food amounts, and beverage energy, noted in 1971-1974 or 1976-1980, was not observed in later surveys. There was an age gradient in changes in most diet and SES associations over time, with largest adverse changes in 12- to 19-y olds. Higher education was associated with lower energy from snack episodes, breakfast skipping, and energy density of foods and these associations did not change over time. Overall, these results suggest both income and education differentials in secular increases in food amounts and energy intakes.