Theory-Based Interventions for Smoking and Obesity (Challenge) Trial

The goal of this clinical trial is to examine a new theory for understanding the processes that govern short-term versus long-term behavior change. The study will examine how people's beliefs and feelings about smoking cessation or weight loss change as they participate in either a smoking cessation program or a weight control program. Also, the study will improve the ability of treatment programs to help people maintain changes in their behavior. The project involves a series of two parallel investigations.

Study 1 tests the hypothesis that intervention methods that influence cost/benefit expectations related to quitting smoking and losing weight will have different effects on long-term smoking cessation and weight loss. The participants are randomly selected to treatment programs that induce heightened or realistic outcome expectations.

Study 2 tests the hypothesis that intervention methods that influence perceived satisfaction with behavior change will have different effects on long-term smoking cessation and weight loss. The participants are randomly selected to treatment programs that induce them to evaluate the consequences of behavior change either in comparison to past or ideal outcomes.

All of the intervention programs used in these studies are based on highly effective treatment procedures. The programs differ in how information about weight loss and smoking cessation is presented, how the participants are encouraged to think about their achievements during the treatment programs, and how much help is given to the participants in organizing their thoughts during the programs.