Doctor of Philosophy (PhD)



Document Type



Dietary fat is related to cardiovascular disease and numerous intensive, controlled clinical trials have successfully reduced dietary fat in symptomatic populations. However, there has been less success in large, community-based studies with healthy or mildly at-risk populations. Little is known about predictors associated with actual change in dietary fat intake and this is an important omission because dietary interventions are more likely to be successful if they are based on factors known to influence behavior. The purpose of this study was to investigate the psychosocial predictors of dietary fat and dietary fat reduction through the framework of the transtheoretical model (TTM) and minor stress. Participants were part of a larger study examining reversal of cardiovascular signs in a healthy population by reducing dietary fat intake to less than 20% of calories from fat. This study consisted of 179 adults who enrolled and had complete data. Participants were randomly assigned to the intervention or control groups. The intervention consisted of attending individual instruction and dietary group. The following measures were administered at baseline and six months: Weekly Stress Inventory and the processes of change (i.e., experiential and behavioral subscales), decisional balance, and self-efficacy questionnaires from the TTM. Dietary fat intake was measured with four-day food records. Hierarchical regression analyses, with BMI as a covariate, were conducted to determine psychosocial predictors of dietary fat intake at baseline and change in dietary fat at six months. The experiential processes variable was the only unique predictor of dietary fat intake and the relationship was moderated by minor stress. The experiential processes were also related to dietary fat reduction. Results of a repeated measure MANOVA revealed that use of behavioral and experiential processes increased for participants in the intervention group over six months of the intervention. Results revealed a modest relationship between TTM variables and dietary fat and dietary fat reduction, with limited evidence that stress moderates this relationship.



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Committee Chair

Phillip Brantley



Included in

Psychology Commons