Original Research A Comparison of Three Dietary Pattern Indexes for Predicting Biomarkers of Diet and Disease Ashima K. Kant, PhD, and Barry I. Graubard, PhD Department of Family, Nutrition, and Exercise Sciences, Queens College of the City University of New York, Flushing, NY (A.K.K.), Division of Cancer Epidemiology and Genetics, Biostatistics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD (B.I.G.) Key words: diet quality, dietary indexes, biomarkers, BMI, blood pressure, NHANES III, components of variance Objective: Examination of dietary indexes in association with objective biomarkers of dietary intake and chronic disease risk is an important step in their validation. We compared three dietary pattern indexes—Healthy Eating Index (HEI), Recommended Foods Score (RFS-24 hour recall), and Dietary Diversity Score for recommended foods (DDS-R)—for their ability to predict biomarkers of dietary intake, obesity, cardiovascular disease, and diabetes. Methods: We used dietary and laboratory data from the third National Health and Nutrition Examination Survey to study these associations in 8719 disease-free adults aged 20 y. The HEI, developed by the USDA, was a sum of scores on consideration of ten individual components; the RFS was a sum of all recommended foods (lean meat, poultry and fish, whole grains, fruits and juices, low-fat dairy, and vegetables) mentioned in the recall; the DDS-R examined whether or not a recommended food was mentioned from each of the five major food groups. The independent association of the dietary pattern indexes with body mass index (BMI), blood pressure, and serum concentrations of several biomarkers were examined using regression methods to adjust for multiple covariates. Results: All indexes were strong independent positive predictors of serum concentrations of vitamin C, E, folate, and all carotenoids (p  0.00001), except lycopene, and were negative predictors of BMI, serum homocysteine, C-reactive protein, plasma glucose, and hemoglobin A1C (p  0.05). The RFS and DDS-R were inversely associated with blood pressure and serum cholesterol (p  0.03). Conclusions: The RFS and DDS-R performed as well or better than the HEI for predicting serum concentration of nutrients and biomarkers of disease risk. INTRODUCTION With increasing recognition of multidimensional nature of diets consumed by free living individuals, dietary patterns have emerged as an alternative or an adjunct to the traditional approach of using single nutrients or food groups as exposures for examining the diet and health associations [1–5]. Recently, both observational studies and intervention trials have provided evidence in support of the pattern based approach to dietary exposures in relation to health [1]. Intuitively, dietary patterns may modify the risk of disease through established risk-factors of disease, and also by relating to intake of micronutrients. Thus, evaluation of dietary patterns for predicting objective biomarkers of dietary intake and risk of chronic diseases is an important step in their validation as predictors of health out- come. In this study we compare three indexes—the Healthy Eating Index of the USDA, the Recommended Foods Score (RFS), and the Dietary Diversity Score (DDS) for their ability to predict biomarkers. The HEI was developed by the USDA to monitor diet quality of the US population [6]. We previously developed the RFS and the DDS which were shown to relate to risk of mortality [7–9]. METHODS This study used data from the third National Health and Nutrition Examination Survey (NHANES III), 1988 –1994. The Address correspondence to: Ashima K. Kant, PhD, Professor, Dept. of Family, Nutrition, and Exercise Sciences, Remsen Hall, Room 306E, Queens College of the City University of New York, Flushing, NY 11367. E-mail: akant@qc.edu Journal of the American College of Nutrition, Vol. 24, No. 4, 294–303 (2005) Published by the American College of Nutrition 294