Health literacy is associated with healthy eating index scores and sugar-sweetened beverage intake: findings from the rural Lower Mississippi Delta

Abstract

Background: Although health literacy has been a public health priority area for more than a decade, the relationship between health literacy and dietary quality has not been thoroughly explored.

Objective: To evaluate health literacy skills in relation to Healthy Eating Index (HEI) scores and sugar-sweetened beverage (SSB) consumption while accounting for demographic variables.

Design: Cross-sectional survey.

Participants/setting: A community-based proportional sample of adults residing in the rural Lower Mississippi Delta.

Methods: Instruments included a validated 158-item regional food frequency questionnaire and the Newest Vital Sign (scores range 0 to 6) to assess health literacy.

Statistical analyses performed: Descriptive statistics, analysis of variance, and multivariate linear regression.

Results: Of 376 participants, the majority were African American (67.6%), without a college degree (71.5%), and household income level <$20,000/year (55.0%). Most participants (73.9%) scored in the two lowest health literacy categories. The multivariate linear regression model to predict total HEI scores was significant (R(2)=0.24; F=18.8; P<0.01), such that every 1-point increase in health literacy was associated with a 1.21-point increase in HEI scores, while controlling for all other variables. Other significant predictors of HEI scores included age, sex, and Supplemental Nutrition Assistance Program participation. Health literacy also significantly predicted SSB consumption (R(2)=0.15; F=6.3; P<0.01) while accounting for demographic variables. Every 1 point in health literacy scores was associated with 34 fewer kilocalories per day from SSBs. Age was the only significant covariate in the SSB model.

Conclusions: Although health literacy has been linked to numerous poor health outcomes, to our knowledge this is the first investigation to establish a relationship between health literacy and HEI scores and SSB consumption. Our study suggests that understanding the causes and consequences of limited health literacy is an important factor in promoting compliance to the Dietary Guidelines for Americans.