Relation between diet cost and Healthy Eating Index 2010 scores among adults in the United States 2007-2010

Background. Food prices may be one reason for the growing socioeconomic disparities in diet quality. Objective. To evaluate the association between diet costs and the Healthy Eating Index-2010 (HEI-2010). Methods. Cross-sectional study based on 11,181 adults from the 2007-2010 National Health and Nutrition Examination Survey, analyzed in spring 2014. Diet cost was estimated by linking dietary data with a national food price database. The HEI-2010, a measure of adherence to the dietary guidelines, was the outcome. The population ratio method was used to estimate the average HEI-2010 scores by quintile of energy-adjusted diet cost Additional analyses evaluated the association between cost and HEI-2010 components. Results. There was a strong positive association between lower energy-adjusted diet costs and lower HEI-2010 scores. The association was stronger among women (p-interaction = 0.003). Lower diet costs were associated with lower consumption of vegetables, fruits, whole grains, and seafood, and higher consumption of refined grains and solid fat, alcohol and added sugars. Conclusions. Lower energy-adjusted diet costs were associated with lower-quality diets. Future efforts to improve the nutritional status of the US public should take food prices and diet costs into account. (C) 2015 Published by Elsevier Inc.