To develop an index of overall diet quality.The Healthy Eating Index (HEI) was developed based on a 10-component system of five food groups, four nutrients, and a measure of variety in food intake. Each of the 10 components has a score ranging from 0 to 10, so the total possible index score is 100.Data from the 1989 and 1990 Continuing Survey of Food Intake by Individuals were used to analyze the HEI for a representative sample of the US population.Frequencies, correlation coefficients, means.The mean HEI was 63.9; most people scored neither very high nor very low. No one component of the index dominated the HEI score. People were most likely to do poorly in the fruit, saturated fat, grains, vegetable, and total fat categories. The HEI correlated positively and significantly with most nutrients; as the total HEI increased, intake for a range of nutrients also increased.The HEI is a useful index of overall diet quality of the consumer. The US Department of Agriculture will use the HEI to monitor changes in dietary intake over time and as the basis of nutrition promotion activities for the population.