The HEI is a scoring system designed by the National Cancer Institute and the United States (US) Department of Agriculture’s Center for Nutrition Policy and Promotion to measure adherence to the Dietary Guidelines for Americans.² The most recent version, HEI-2020, consists of 13 dietary components categorized into two groups: adequacy and moderation.³

The components under adequacy encourage higher consumption of fruits, vegetables, whole grains, dairy, total protein foods, seafood, plant proteins, and fatty acids. In contrast, the moderation components assess the intake of refined grains, sodium, saturated fats, and added sugars, which should be limited.^4,5

Each component is assigned a score ranging from 0 to 5 or 10, with the total HEI score ranging from 0 to 100. A higher HEI score indicates better alignment with dietary guidelines. The data used for HEI calculations are typically derived from dietary recalls, food frequency questionnaires, and national nutrition surveys.^4,6

The HEI has been widely utilized in epidemiological studies to evaluate dietary quality. It has also been used in public health research to track diet quality trends and guide interventions aimed at improving population nutrition.

A growing body of research highlights the strong associations between HEI scores and various health outcomes. Higher HEI scores have been linked to reduced risks of cardiovascular disease, stroke, and all-cause mortality.^5,6

Furthermore, a prospective study found that individuals with the highest HEI scores had a 16% lower risk of cardiovascular disease and an 18% reduction in all-cause mortality compared to those with the lowest scores.⁶

HEI scores have been associated with markers of biological aging. One study found that higher HEI scores correlated with lower epigenetic age acceleration, suggesting potential longevity benefits.⁷

Moreover, HEI scores have also been inversely related to frailty and chronic disease development, further underscoring their predictive value for long-term health outcomes.⁸

Numerous studies have shown that HEI scores can predict overall health status in various populations, including older adults, individuals with chronic diseases, and different racial and ethnic groups.

An increasing number of studies in nutrition and health have been reporting the various benefits of dietary patterns such as the ketogenic and Mediterranean diets, especially the benefits associated with cardiovascular and metabolic health. Studies have also assessed the HEI of these dietary patterns to examine their alignment with national dietary guidelines.

Mediterranean Diet: Research suggests that adherence to a Mediterranean diet is associated with reduced risks of cardiovascular disease and improved cognitive function, making it one of the most recommended dietary patterns for overall health.⁹ This diet is rich in whole grains, vegetables, fruits, seafood, and healthy fats and scores high on the HEI, as it aligns closely with recommended nutrient intake.¹⁰

Dietary Approaches to Stop Hypertension (DASH) Diet: Designed to lower hypertension, this diet emphasizes fruits, vegetables, and lean proteins while limiting sodium and added sugars. It also consistently scores high on HEI assessments.⁸ Research has shown that the DASH diet significantly lowers blood pressure and improves lipid profiles, further reinforcing its role in cardiovascular disease prevention.⁶

Plant-Based Diets: Diets emphasizing whole plant foods tend to score well on the HEI, as they naturally align with many of the adequacy components while limiting processed foods and saturated fats.¹⁰ Plant-based diets have also been linked to a lower risk of metabolic syndrome and certain cancers, making them a favorable option for long-term health benefits.⁸

Ketogenic Diet: Due to its high fat and low carbohydrate content, the ketogenic diet scores poorly on the HEI, particularly due to its restriction of whole grains, fruits, and certain vegetables.⁶ While ketogenic diets have been associated with short-term weight loss and improved insulin sensitivity, concerns about their long-term effects on heart health and micronutrient deficiencies remain.⁵

Paleo Diet: The Paleo diet focuses on consuming whole foods such as lean meats, fish, fruits, vegetables, nuts, and seeds while avoiding processed foods, dairy, and grains. While this diet includes many nutrient-dense foods, it scores lower on the HEI due to its exclusion of whole grains and dairy, which are key components of a balanced diet.⁷

While the HEI provides a useful framework for comparing dietary patterns, it is important to note that the scoring system does not account for all aspects of diet quality, such as meal timing, food processing, and bioavailability of nutrients.

Additionally, personal preferences, cultural influences, and economic factors play significant roles in dietary adherence and health outcomes.

The substantial research conducted on various dietary patterns and their HEI scores suggests that nutritional intake can be optimized through small, practical changes to one’s diet. These changes include:

• Increasing whole foods and fiber consumption: Incorporate more whole grains, vegetables, fruits, and legumes into daily meals. Additionally, consuming fiber-rich foods, such as legumes and whole grains, is known to enhance gut health and support sustained energy levels.^1,6,8,11
• Limiting processed and refined foods: Reduce intake of refined grains, added sugars, and sodium to align with the moderation components of the HEI. Furthermore, instead of snacking on processed foods or sugar-sweetened snacks, choose nutrient-dense snacks like nuts, yogurt, or fresh fruit. Substituting sugary drinks with water, herbal teas, or other low-calorie alternatives can also significantly improve HEI scores.^6,8,11
• Consuming healthy proteins and fats: Prioritize plant-based proteins, lean meats, and seafood while reducing red and processed meat consumption. Furthermore, replace saturated fats with sources rich in unsaturated fats, such as nuts, seeds, and olive oil.¹¹
• Diversifying nutrient sources: Ensure a wide variety of nutrient-dense foods such as fresh fish, green leafy vegetables, citrus fruits, and mushrooms to enhance the intake of essential vitamins and minerals, including vitamin D, calcium, and potassium.^1,6,11
• Choosing home-cooked food: Preparing meals at home increases control over ingredients and portion sizes, promoting healthier eating habits. Additionally, opt for steaming, grilling, and baking over frying to preserve nutrients and avoid excess unhealthy fats. Studies suggest that preparing meals in advance ensures access to balanced, nutrient-rich options and minimizes reliance on processed foods.¹²​​​​​​​

Overall, the HEI serves as a robust tool for assessing diet quality at both individual and population levels. It offers valuable insights into how dietary patterns align with national guidelines and their implications for health outcomes.

Higher HEI scores are consistently associated with lower risks of chronic diseases and increased longevity. Therefore, by making targeted dietary adjustments, individuals can enhance their HEI scores and contribute to better overall health and disease prevention.

As the field of nutritional epidemiology continues to evolve, the HEI will remain an essential measure for evaluating diet quality and guiding public health policies.

References