Evaluation of the Healthy Eating Index-2005 Patricia M. Guenther, PhD, RD: US Department of Agriculture, Center for Nutrition Policy and Promotion Jill Reedy, PhD, RD: National Cancer Institute (NCI) Susan M. Krebs-Smith, PhD, RD: NCI Bryce B. Reeve, PhD: NCI JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION

Tests Content validity Construct validity Evaluation of the Healthy Eating Index-2005 Tests Content validity Construct validity Internal consistency (reliability)

Evaluation of the Healthy Eating Index-2005 Content validity Extent to which the measure captures the variety of attributes that make up the construct Includes face validity Test Check against Dietary Guidelines

Evaluation of the Healthy Eating Index-2005 Construct validity Extent to which the measure is consistent with theoretical hypotheses Tests Exemplary menus Smokers vs nonsmokers Correlations with energy Principal components analysis

Sources of exemplary menus Evaluation of the Healthy Eating Index-2005 Sources of exemplary menus MyPyramid.gov Dietary Approaches to Stop Hypertension (DASH) Eating Plan Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating American Heart Association No-Fad Diet

Healthy Eating Index-2005 scores for exemplary menus Evaluation of the Healthy Eating Index-2005 Healthy Eating Index-2005 scores for exemplary menus MyPyramid DASH Harvard AHA Total Grains 5 4.8 Whole Grains Total Vegetables Dark Green/Orange Vegetables & Legumes 4.9 Total Fruit Whole Fruit Milk 10 0.9 8.7 Meat & Beans Oils Sodium Saturated Fat Calories from SoFAAS 20 Total 100 99.8 90.9 98.6 SoFAAS: Solid Fats, Alcoholic beverages, and Added Sugars

Evaluation of the Healthy Eating Index-2005 Population data used National Health and Nutrition Examination Survey, 2001-2002 N = 8650 One 24-hour recall per respondent Nutrients MyPyramid food groups

Concurrent criterion validity Evaluation of the Healthy Eating Index-2005 Concurrent criterion validity Distinguishes between groups with known differences in the quality of their diets Test Smokers vs nonsmokers

Smokers vs nonsmokers Number of differences in mean component scores Evaluation of the Healthy Eating Index-2005 Smokers vs nonsmokers Number of differences in mean component scores Original Healthy Eating Index 5 of 10 Healthy Eating Index-2005 9 of 12 Differences in mean total score Original Healthy Eating Index 5.5 points Healthy Eating Index-2005 8.6 points Conclusion: Healthy Eating Index-2005 distinguishes between smokers and nonsmokers better than original Healthy Eating Index

Correlations of original Healthy Eating Index scores and energy intake Evaluation of the Healthy Eating Index-2005 Correlations of original Healthy Eating Index scores and energy intake Component scores Fruit .05 Vegetables, Milk, Variety, Meat, Grains .29 to .44 Fat, Saturated fat (% calories) -.08 to .09 Cholesterol -.43 Sodium -.69 Total score .09 Low because some food-group correlations are positive and others negative

Correlations of Healthy Eating Index-2005 scores and energy intake Evaluation of the Healthy Eating Index-2005 Correlations of Healthy Eating Index-2005 scores and energy intake Component scores Calories from SoFAAS -.22 Sodium, Saturated Fat -.08 to -.11 Vegetables, Grains, Fruit -.05 to -.10 Milk 0 Oils, Meat and Beans .06 to .08 Total score -.14 Low because all component correlations are low Conclusion: Healthy Eating Index-2005 successfully uncouples diet quantity and diet quality SoFAAS: Solid Fats, Alcoholic beverages, and Added Sugars

Principal component analysis scree plot Evaluation of the Healthy Eating Index-2005 Principal component analysis scree plot Variance accounted for by each factor Number of factors Eigenvalue  Conclusion: Multiple factors underlie the Healthy Eating Index-2005

Types of reliability Test-retest reliability does not apply Evaluation of the Healthy Eating Index-2005 Types of reliability Test-retest reliability does not apply All sources of error attributable to Respondent recall Data collection and coding Inter-rater reliability does not apply No judgment required Internal consistency Only type that could be tested

Evaluation of the Healthy Eating Index-2005 Internal consistency Degree of association among the components of an index Test Cronbach’s alpha coefficient

Internal consistency Cronbach’s coefficient alpha = 0.43 Evaluation of the Healthy Eating Index-2005 Internal consistency Cronbach’s coefficient alpha = 0.43 Anticipated to be low because Healthy Eating Index-2005 components Do not all measure the same thing Relationships among them vary Conclusion: Healthy Eating Index-2005 is best used as a set of profile scores; otherwise, much information will be lost

The Healthy Eating Index-2005 Evaluation of the Healthy Eating Index-2005 Conclusions The Healthy Eating Index-2005 Is a valid measure of compliance with the 2005 Dietary Guidelines for Americans Yields high scores for exemplary menus Distinguishes between groups with known differences in diet quality Uncouples diet quality and diet quantity by using a density approach Provides a valid set of profile scores for assessing diet quality