Preventing or reducing obesity is one factor that has been hailed as a way to improve quality of life, reduce recurrence, and increase survival rates among breast cancer survivors. An experienced team of multi-disciplinary researchers has developed an innovative and unique approach to encourage enhanced nutrition and exercise behaviors in this population using principles of behavioral economics. In particular, the use of social norms or exemplars has been shown in other applications to be effective, and if successful in this population could be inexpensively scaled up for widespread adoption. The proposed pilot study develops a system of text messages for social/mobile media that will provide ongoing reinforcement of desired behavior in breast cancer survivors. These messages would focus on achieving compliance with the expert-developed nutrition and exercise recommendations of the American Cancer Society. In the main study, 310 breast cancer survivors will be randomly placed in intervention and control groups for the 12 week study. Behavior change will be measured using established measures of self-reported behavior. In a sub-study, 60 of the breast cancer survivor participants will also provide blood and urine samples so changes in biomarkers can be assessed. The impact of the study will be measured by biomarkers and self-reported survey responses.