Date of Award


Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy in Applied Cognitive Science and Human Factors (PhD)

Administrative Home Department

Department of Cognitive and Learning Sciences

Advisor 1

Erich Petushek

Committee Member 1

Andrew Fiss

Committee Member 2

Joseph Carlson

Committee Member 3

Kelly Steelman


Context—Improving diet can reduce the risk of chronic health conditions such as cancer and heart disease. However, people continue to make poor dietary health decisions. A novel intervention based on the science of behavior change and incorporating Human-Centered Design (HCD) methodology is needed to boost informed dietary decision-making.

Objective—This research presents a Behavior Change Wheel (BCW), Human-Centered Design (HCD) approach to develop a novel high-usability video intervention that will increase informed decision-making for whole-grain dietary decisions. The intervention will target college students, improving habits that can carry on throughout later adulthood.

Design—Study 1 consisted of preliminary data that measured knowledge about the relationship between lifestyle behaviors and health outcomes and identified perceived challenges to healthier lifestyle behaviors among college students. Study 2 is designed to test the usability of the novel educational video intervention. Study 3 is a randomized controlled experiment designed to assess the effectiveness of the intervention on increasing informed dietary whole-grain decisions. Finally, study 4 is designed to identify what factors contribute to the intervention's success and/or failure, what mediating factors influence whole-grain decisions, and how effectively the intervention impacts behavior change determinants, self-efficacy, and outcome expectations.

Results—Study 1 suggests that medical students hold insufficient knowledge regarding the relationship between lifestyle behaviors and risk of health outcomes. Participants did not rate the importance of decisions on health in-line with current epidemiological evidence. Study 2 identified user insights to improve the intervention. Results from Study 3 were mixed, showing that the intervention did improve ‘gist understanding’ for the student sample group. Results from study 4 show that that the knowledge constructs can develop and strengthen self-efficacy and outcome expectancy and that these constructs impact whole-grain intake.

Conclusion—The outcome of this research is the creation of the best available intervention to improve informed whole-grain decision-making. The intervention fulfills ethical demands for increasing informed dietary decision-making. This research also provides evidence of the predictive ability of some novel knowledge factors and the identification of mediator variables. These findings will be valuable for future intervention development and testing.