Higher health literacy score is associated with better healthy eating index in Iranian adults

•We investigated the association between health literacy and healthy eating index 2015.•There was positive association between health literacy and healthy eating index 2015•We found a positive relationship between physical activity and health literacy.•Among the healthy eating index components, only saturated fats were significantly related to health literacy. Although there is some evidence for the importance of health literacy (HL), many health complications and nutrition knowledges such as portion size assessment, knowing the food labels, and choosing the nutrition sources affecting diet quality, data about HL and healthy eating index (HEI) are limited and controversial. The aim of this study was to evaluate the associations between HL and HEI in adults. This cross-sectional study included 261 adults 18 to 65 y of age from five districts of Tehran, Iran. HL was estimated using the Health Literacy for Iranian Adult (HELIA) questionnaire. Dietary intake, sociodemographic data, physical activity, and anthropometric measurements were collected using validated questionnaires. Diet quality was assessed based on HEI-2015 scores using data from a food frequency questionnaire. Despite components of HEI-2015, the association between HEI-2015 and HL tertiles was significant (P of crude model = 0.007) even after adjustment for possible confounders. Multivariate regression showed a positive relationship between HL and HEI-2015 that was significant before (β = 0.12, P = 0.04) and after controlling for the confounding effect in model 1 (β = 0.14, P = 0.03). Additionally, a positive association between physical activity and HL was shown (β = 0.12, P = 0.03) and finally among the HEI components, only saturated fats were significantly related to HL (β = –0.11, P = 0.01). Findings from the present study confirmed a considerable association between HL and HEI and shows HL levels have an important role in adherence to the Iranian Dietary Guidelines.