Date of Award


Degree Type


Degree Name

Master of Science in Nutrition and Food Science


Nutrition and Food Sciences

First Advisor

Geoffrey W. Greene


Statement of the Problem: Nutrition literacy, derived from health literacy, is the ability to understand basic information needed to make appropriate nutrition decisions. Critical nutrition literacy (CNL), the highest level of nutrition literacy, is defined as the ability to critically analyze and apply nutrition information. Although studies have explored the lower levels of nutrition literacy (functional and interactive), CNL has seldom been investigated. One instrument developed to measure CNL, the Critical Nutrition Literacy Tool (CNLT), was found to have strong psychometrical validity and reliability; however, the external validity of the instrument is unknown. Thus, the purpose of this research was to further examine CNL, through further validation of the CNLT, in a large sample of college students in the U.S. The aims of this paper are to: examine the relationship between CNL and dietary quality; examine its relationship to related constructs, such as critical decision making (CDM); and determine if an introductory level nutrition course designed to increase nutrition knowledge will also increase CNL. Methods: The methods utilized in this thesis were comprised of three studies. The first study was a secondary data analysis of a cross-sectional survey that examined the relationship between CNL and dietary quality. The second study was a randomized-control trial, using an existing online, problem-based learning program, where the relationship between CNL and CDM scores were evaluated. The third and final study was a secondary data analysis of a non- experimental, pre-post study design of a 4 credit, 13-week, academic course intervention, aimed to determine whether CNL could be increased. Critical nutrition literacy was measured using a validated, 7-item critical nutrition literacy scale.11 Items were evaluated using a 5-point Likert scale ranging from 1=strongly disagree to 5 = strongly agree. Critical nutrition literacy scores were then divided into tertiles to produce three distinct groups: lower critical nutrition literacy, moderate critical nutrition literacy and higher critical nutrition literacy. Summary of Results: This thesis is the first study to explore critical nutrition literacy (CNL), as it is related to dietary quality and critical decision making (CDM), in a diverse sample of college students. Although positive, critical nutrition literacy has little relationship with markers of diet quality, such as cups of fruits and vegetables and teaspoons of added sugars. As well, there was no significant relationship between CDM score, measured by critical decision-making skills, and CNL. It can be suggested that other factors may influence or mediate the relationship between CNL, CDM and behavior change. Being able to target a specific factor, such as students’ nutrition knowledge, may lead to an increase in ones’ critical nutrition literacy skills, which was indicated in the results of the nutrition course intervention. Future interventions should focus their attention on developing more sensitive and comprehensive CNL instruments, through experimental designs, to better explore and understand the relationship with eating behavior and CDM.

Available for download on Monday, April 19, 2021