For more information, read an Overview of the Methods & Calculations.
The steps of the HEI scoring algorithm are:
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Deriving Sums. For each HEI component, dietary constituents are summed together (e.g., Greens and Beans is created from the sum of dark green vegetables and legumes (beans and peas)).
For the HEI-2015, the components and associated dietary constituents are noted below:
HEI-2015 Components and Associated Dietary ConstituentsComponents Units Dietary Constituents From FPED (or other food-based database) Whole Fruits cup eq. Citrus, Melons, Berries + Other Intact Fruits Total Fruits cup eq. Total Fruit Greens and Beans cup eq. Dark Green Vegetables + Legumes (Beans and Peas) in cup equivalents Total Vegetables cup eq. Total Vegetables + Legumes (Beans and Peas) in cup equivalents Whole Grains oz. eq. Whole Grains Refined Grains oz. eq. Refined Grains Dairy cup eq. Total Dairy Seafood and Plant Proteins oz. eq. Seafood (high in n-3) + Seafood (low in n-3) + Soy Products + Nuts and Seeds + Legumes (Beans and Peas) in oz equivalents Total Protein Foods oz. eq. Total Meat, Poultry, and Seafood (including organ meats and cured meats) + Eggs + Nuts and Seeds + Soy + Legumes (Beans and Peas) in oz equivalents Added Sugars tsp. eq. Added Sugars From FNDDS (or other nutrient database) Fatty Acids g (Total Monounsaturated Fatty Acids + Total Polyunsaturated Fatty Acids)/Total Saturated Fatty Acids Saturated Fats g* Total Saturated Fatty Acids Sodium mg Sodium Energy kcal Total Energy cup eq.=cup equivalents; oz. eq.=ounce equivalents; tsp. eq.=teaspoon equivalents; g=grams; g*= fatty acids are calculated in grams but converted to energy in the scoring process; mg=milligrams
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Constructing Ratios. The appropriate ratios are constructed for each individual. Usually these are the ratios of the dietary constituents to 1000 kcal of energy, with the exception of fatty acids. Fatty acids use the ratio of the sum of monounsaturated and polyunsaturated fatty acids to saturated fatty acids. Also, two components (saturated fat and added sugars) are expressed on a percent of calories basis. To convert to a percent of calories basis, grams of saturated fat should be multiplied by 9 to convert g to kcal, and added sugars should be multiplied by 16 to convert teaspoons to kcal, prior to dividing by total energy.
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Scoring. The ratios are scored according to the HEI scoring standards for each component. The component scores are summed to calculate the total score. Step 4 is different depending on purpose; see two options below.
For Describing Dietary intake:
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Calculating Means. The mean score is the mean of the component scores and total scores across individuals. When more than one 24HR is available, the score is calculated by summing across all days per person before applying the scoring algorithm.
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For Examining Association between Diet and Another Variable:
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Performing Regression Analysis. Once a total score is estimated for an individual, it may be entered as predictor variable in an appropriate regression model. When more than one 24HR recall per person is available, the score is calculated by summing across all days per person before applying the HEI scoring standards and performing regression analysis.