Nutrition and health literacy: a systematic review to inform nutrition research and practice.

Health literacy is defined as the degree to which individuals obtain, process, and understand basic health information and services to make informed health decisions. Health literacy is a stronger predictor of health than age, income, employment, education, and race. Although the field has grown during the past decade, most health literacy research does not explicitly focus on food or nutrition, and dietetics practitioners often remain unaware of patients' health literacy level. The purpose of this systematic review was to summarize the literature on nutrition and health literacy to enhance dietetics practitioners' awareness of the importance of health literacy in practice and research. Of the 33 studies reviewed, four focused on measurement development, 16 on readability assessments, and 13 on individual literacy skills assessments. Collective evaluation revealed four noteworthy gaps, including the need to use more comprehensive assessment approaches that move beyond readability and numeracy to address the full spectrum of health literacy factors; the need to apply more robust experimental studies to examine the effectiveness of health literacy interventions among individuals, communities, health care providers, and health care systems; the need to explore the moderating and mediating roles of an individual's health literacy status on nutrition outcomes; and the need to examine long-term effects of health literacy interventions on nutrition outcomes. This article defines health literacy gaps and opportunities in nutrition research and practice, and calls for continued action to elevate the role of dietetics practitioners in addressing health literacy.