 Women receiving chemotherapy for early stage breast cancer often gain weight and body fat, and this contributes to the health burden that cancer survivors face. Weight gain is a concern not only for overall health status, but also as a possible factor for risk of cancer recurrence. Unfortunately achieving weight loss, after a gain has occurred, is difficult, and there are no satisfactory methods for maintenance of weight loss. This study proposes to design and test a novel telephone-based intervention for preventing weight gain during treatment for breast cancer in a pilot, randomized study. The 12-month intervention will target maintenance of current weight and prevention of body fat gain using counseling for moderate exercise and a low-fat, high fruit-vegetable diet. The counseling approach will be based on motivational interviewing techniques and will be delivered through telephone appointments. Motivational interviewing is a client-centered type of counseling that elicits active participation of the patient. By taking a more active role, patients may be more likely to follow through with the recommended lifestyle changes. Study endpoints will include blood markers of dietary compliance, pedometer steps, self-monitoring logs, questionnaires including quality of life and anthropometric measures including body fat by DEXA. An important goal of the study is to establish recruitment methods and demonstrate recruitment rates in newly diagnosed stage I-IIIA breast cancer patients. The study data also will demonstrate implementation of the counseling approach and provide a basis for sample size estimates for a larger trial. This type of intervention, namely a combination of exercise and diet, has been indicated to have good potential for prevention of recurrence. It is therefore necessary to develop effective methods for eliciting these behaviors. 