Predicting Dieting Behavior by Using, Modifying, and Extending the Theory of Planned Behavior

The theory of planned behavior (TPB) was used, modified, and extended to predict dieting intention and behavior. Female undergraduates ( n = 256) responded to a survey assessing variables from the TPB and additional predictor variables. Seventy-eight of these participants also completed a follow-up questionnaire 3 months later that assessed their subsequent weight-loss behavior. A model was developed for dieting using path analysis to assess the most significant paths to intention to diet and follow-up dieting. In the final predictor model, 77% of the variance in intention to diet and 46% of the variance in follow-up dieting were explained. The strongest predictor of intention to diet was direct attitude, and the strongest predictor of follow-up dieting was prior dieting. This study also included a confirmatory analysis of the dieting model (n=117). Approximately 2/3 of the paths were confirmed, and 72% of the variance in intention was explained.