Background: Disparities in the health status of blacks and whites have persisted despite considerable gains in improved health of the U.S. population. Tracking changes in black-white differentials in dietary attributes over time may help in understanding the contribution of diet to these disparities.
Methods: Data were used from four National Health and Nutrition Examination Surveys conducted between 1971 and 2002 for trends in self-reported intakes of energy, macronutrients, micronutrients, fruits and vegetables, and the energy density of foods among U.S. non-Hispanic black (n=7099) and white (n=23,314) men and women aged 25 to 74 years. Logistic and linear regression methods were used to adjust for multiple covariates and survey design.
Results: Energy intake, amount of food, and carbohydrate energy increased, whereas percentage of energy from protein, fat, and saturated fat decreased over time in all race and gender groups (p<0.001). In whites and in black women, energy density increased (p<0.001) in parallel to increases in obesity prevalence. In all surveys, black men and women reported lower intakes of vegetables, potassium, and calcium (p<0.001) than their white counterparts. In men, the race differential in calcium intake increased across surveys (p=0.004).
Conclusions: Dietary intake trends in blacks and whites from 1971 to 2002 were similar, which suggests that previously identified dietary risk factors that differentially affect black Americans have not improved in a relative sense.