While dieting is relatively normative in our society, it is controversial within the fields of eating disorders and obesity. Dieting for weight loss has been touted by the obesity prevention field as a solution to the growing obesity epidemic, yet a body of research in the eating disorders field has also implicated it in the etiology and maintenance of eating pathology. Thus, a divergence in approaches toward dieting has emerged, with both pro-dieting and anti-dieting messages being recommended. Little is known, however, about the impact of these two types of messages on immediate and short-term psychological functioning and weight control intentions and behaviors. The current study sought to explore this gap in the extant literature by conducting an experimental study that evaluated the two messages. Undergraduate women (N=139) were randomly assigned to either a pro-dieting, anti-dieting, or no-dieting (control) message condition. Psychological functioning and weight control variables were assessed at baseline, post-test, and a two-week follow-up. Results indicated that the pro-dieting message resulted in significantly greater post-test perceived pressure to lose weight, dieting intentions, and thin-ideal internalization intentions while the anti-dieting message yielded significantly lower post-test bulimic intentions. Healthy eating behavior significantly increased from baseline to follow-up in the pro-dieting condition while there were no changes in the other two conditions. Post-test perceived pressure was found to fully mediate the relationship between diet message and post-test dieting, bulimic, thin-ideal internalization, and healthy eating intentions as well as follow-up healthy eating behavior. Trait thin-ideal internalization levels moderated the relationship between diet message and post-test perceived pressure and thin-ideal internalization intentions. Exploratory analyses revealed that overweight participants in the pro-dieting condition increased significantly from pre to post-test on state body dissatisfaction and had the highest level of post-test perceived pressure compared to all other groups. Non-overweight participants in the pro-dieting condition also had significantly greater post-test perceived pressure to lose weight than both weight status groups in the other two conditions. Findings are discussed in the context of the prevention goals of the obesity and eating disorders fields. Limitations of the study and directions for future research are offered.