Currently, there is a public health need for effective and economical strategies designed to influence appropriate dietary modifications in the general public (e.g., reduction of dietary fats). To address this need, this study applied the behavioral systems framework in its design and application to nutrition change. The primary research question was to experimentally assess the differential impacts of a combined media and personal interaction condition (specifically using participant modeling procedures) to a condition that combined media and personal attention strategies. A no treatment condition was also employed. Previous research had shown robust changes with interventions that combined media and personal interaction. This study addressed whether those changes were due to the procedures or to the personal attention received. To examine this question, self-report data on foods purchased and data from supermarket receipts were collected from 45 households across the 3 conditions. Results indicated that persons in the media and personal interaction condition did demonstrate significant changes in the desired direction in the percentage of total fat content in foods purchased. A comparable change was not noted in the other conditions. Thus, it was concluded that some combination of factors (i.e., modeling, reinforcement, feedback, and goal setting) in addition to the procedures used in the video and personal attention provided in the participant modeling, were responsible for the dramatic decreases in total fats. From this study, it was not possible to determine which of the psychological principles were most effective in inducing change. In addition to the experimental findings, subject characteristics (e.g., beliefs, knowledge, health locus of control, skills, self-efficacy, etc.) was examined. The results did not lead to a general set of individual characteristics being related to nutritional outcome. Rather, the information contributed to a clearer understanding of the needs of the sample and the environmental constraints and inducements for nutritional change in that target group. Given the threat of dietary fat to the health of the American public, the reduction in total fat found in this study was an important finding. The application of the behavioral systems framework provided the necessary information to enable the message of the video and the modeling, feedback, and goal setting components to be effective in changing total fats among a segment of the target sample. / Ph. D.