Date of Award
Doctor of Philosophy
Katie E. Mosack
Raymond Fleming, Amy E. Harley, W. Hobart Davies, Shawn Cahill
Intervention, Motivation, Nutrition, Self-As-Doer, Self-Identity, Theory of Planned Behavior
Background: Self-identity predicts healthy eating behaviors and intentions above and beyond Theory of Planned Behavior components (TPB; i.e., attitudes, perceived behavioral control, and subjective norms), but interventions exploring the relationship between self-identity and motivation are limited. Self-as-doer identity may be an important point of intervention for healthy eating behaviors (Houser-Marko & Sheldon, 2006). Therefore, I investigated whether the experimental manipulation of a self-as-doer identity predicted improved healthy food consumption, intentions, and increased self-identity as a healthy eater compared to women who received nutritional education or no intervention directly following the intervention and one month post-intervention.
Method: Participants were 79 women ages 18-53 years old (M=22.92, SD=6.92) who were randomly assigned to one of three conditions (i.e., control, education only, or education and self-as-doer activity) and asked to record their diet for four days using a food diary and an online food frequency questionnaire. Intentions to eat a healthy diet, nutrition knowledge, identity as a healthy eater, and healthy eating behaviors were recorded over a six week period: before, after, and one month post-intervention. Repeated measures ANOVAs and hierarchal linear regressions were performed to determine if the self-as-doer intervention created change and predicted increases in intentions, self-identity, and healthy food consumption.
Results: Healthy eater identity predicted intentions to eat a healthy diet and overall healthy eating behavior above and beyond TPB components, but did not predict specific food group eating behaviors. Self-as-doer participants strengthened self-identity and intentions over the course of the study, but no group differences were found. Self-as-doer participants increased overall healthy eating behaviors while education and control participants decreased overall healthy eating behaviors. Self-as-doer participants ate significantly more healthy foods at time three than did education and control participants.
Discussion: Findings support the role of self-identity in predicting intentions and overall healthy eating behaviors and demonstrate a causal relationship between self-as-doer identity and change in healthy eating identity, intentions, and some behaviors. The self-as-doer intervention may provide individuals with the unique motivational tools needed for diet change. Further research refining the self-as-doer intervention, targeting other health behaviors, and employing the intervention in a clinical population is needed.
Brouwer, Amanda, "Motivating Healthy Diet Behaviors: The Self-As-Doer Identity" (2012). Theses and Dissertations. Paper 1.