Nutrition Literacy Is Not Sufficient to Induce Needed Dietary Changes in Nonalcoholic Fatty Liver Disease

Abstract

Introduction: Dietary and lifestyle changes are the first line of therapy for nonalcoholic fatty liver disease (NAFLD), the most prevalent liver disease in the western world. Nutrition literacy is the ability to understand nutrition information and implement that knowledge. We aimed to compare indicators of nutrition literacy in subjects with and without NAFLD in a representative US cohort.

Methods: In a cross-sectional study using data from the National Health and Nutrition Examination Survey 2017-2018 cycle, we included 2,938 adult subjects with complete dietary and vibration-controlled transient elastography data and no alternative reason for hepatic steatosis. Nutrition literacy was assessed using questionnaires. Diet perception accuracy was assessed by comparing self-reported diet quality with objective diet quality scores-the Healthy Eating Index and alternative Mediterranean diet score-to assess real-world application of nutrition knowledge.

Results: Nutrition literacy was not different between subjects with or without NAFLD ( P = 0.17): more than 90% of subjects reported using nutrition labels, and most of them correctly identified the meaning of daily value. Subjects with NAFLD had a lower-quality diet (Healthy Eating Index, P = 0.018; alternative Mediterranean diet, P = 0.013) and rated their diet as poorer ( P < 0.001). On self-assessment, only 27.8% of subjects overestimated their diet quality, while 37.5% consumed more calories than their self-assessed needs. Both accuracy measures were similar between subjects with NAFLD and those without ( P = 0.71 and 0.63, respectively). Subjects with NAFLD were more likely to report being advised to lose weight (42.1% vs 16.5%, P < 0.001) or to attempt losing weight (71.9% vs 60.9%, P < 0.001). Diet quality was not better in subjects with NAFLD who received dietary recommendations.

Discussion: Subjects with NAFLD have poor diet quality despite receiving medical recommendations to lose weight and having nutrition literacy and perception that are comparable with subjects without NAFLD. Educational approaches may not be sufficient to promote weight loss and improve diet quality in NAFLD.

Figure 1.. Subjects with NAFLD are more likely to rate their diet as poorer quality.

(A) Histogram of the response to the question: “In general, how healthy is your overall diet?” by NAFLD status. (B) In subjects with NAFLD, histogram of the response to the question: “In general, how healthy is your overall diet?” by whether or not their doctor had told them to lose/reduce their weight. P-values for trend calculated using the Kruskal-Wallis test.