Diet quality of Americans differs by age, sex, race/ethnicity, income, and education level.

An index that assesses the multidimensional components of the diet across the lifecycle is useful in describing diet quality. The purpose of this study was to use the Healthy Eating Index-2005, a measure of diet quality in terms of conformance to the 2005 Dietary Guidelines for Americans, to describe the diet quality of Americans by varying sociodemographic characteristics in order to provide insight as to where diets need to improve. The Healthy Eating Index-2005 scores were estimated using 1 day of dietary intake data provided by participants in the 2003-2004 National Health and Nutrition Examination Survey. Mean daily intakes of foods and nutrients, expressed per 1,000 kilocalories, were estimated using the population ratio method and compared with standards that reflect the 2005 Dietary Guidelines for Americans. Participants included 3,286 children (2 to 17 years), 3,690 young and middle-aged adults (18 to 64 years), and 1,296 older adults (65+ years). Results are reported as percentages of maximum scores and tested for significant differences (P ≤ 0.05) by age, sex, race/ethnicity, income, and education levels. Children and older adults had better-quality diets than younger and middle-aged adults; women had better-quality diets than men; Hispanics had better-quality diets than blacks and whites; and diet quality of adults, but not children, generally improved with income level, except for sodium. The diets of Americans, regardless of socioeconomic status, are far from optimal. Problematic dietary patterns were found among all sociodemographic groups. Major improvements in the nutritional health of the American public can be made by improving eating patterns. Published by Elsevier Inc.