The Healthy Eating Index (HEI) is a tool to assess how well a diet aligns with the Dietary Guidelines for Americans (DGA). The HEI-2015, updated to reflect the 2015–2020 DGA, includes 13 components, replacing Empty Calories with Saturated Fat and Added Sugars. The HEI-2015 maintains consistency with previous versions, with similar weighting and scoring standards, and improves face validity by covering a range of intakes. It uses radar graphs to visualize diet quality and provides a total score representing overall diet quality. The HEI-2015 accounts for all energy from alcohol within total energy, not as a separate component. Legumes are now counted toward all four components (vegetables, protein, total vegetables, and total protein foods), improving the representation of dietary variety. The HEI-2015 scoring standards are based on the USDA's Healthy US-Style Eating Patterns, with adjustments for the 2015–2020 DGA. The HEI-2015 is designed to be scored from 0 to 100, with scores interpreted based on component scores and overall diet quality. The HEI-2015 reflects the updated DGA, emphasizing dietary patterns and tracking specific nutrients like saturated fats and added sugars. It is used to evaluate diet quality in various settings, including individual diets, food supply, and restaurant menus. The HEI-2015 is a valuable tool for assessing dietary quality and guiding public health initiatives.The Healthy Eating Index (HEI) is a tool to assess how well a diet aligns with the Dietary Guidelines for Americans (DGA). The HEI-2015, updated to reflect the 2015–2020 DGA, includes 13 components, replacing Empty Calories with Saturated Fat and Added Sugars. The HEI-2015 maintains consistency with previous versions, with similar weighting and scoring standards, and improves face validity by covering a range of intakes. It uses radar graphs to visualize diet quality and provides a total score representing overall diet quality. The HEI-2015 accounts for all energy from alcohol within total energy, not as a separate component. Legumes are now counted toward all four components (vegetables, protein, total vegetables, and total protein foods), improving the representation of dietary variety. The HEI-2015 scoring standards are based on the USDA's Healthy US-Style Eating Patterns, with adjustments for the 2015–2020 DGA. The HEI-2015 is designed to be scored from 0 to 100, with scores interpreted based on component scores and overall diet quality. The HEI-2015 reflects the updated DGA, emphasizing dietary patterns and tracking specific nutrients like saturated fats and added sugars. It is used to evaluate diet quality in various settings, including individual diets, food supply, and restaurant menus. The HEI-2015 is a valuable tool for assessing dietary quality and guiding public health initiatives.