Feasibility of High Levels of Energy Expenditure From Physical Activity for Breast Cancer Survivors

Inclusion Criteria:

* Women \< age 71 in good general health.
* Prior diagnosis of breast cancer.
* At least 3 months from completion of any cytotoxic chemotherapy or radiation or surgery. May continue to take endocrine therapy and/or maintenance trastuzumab.
* Body Mass Index (BMI) 30-45 kg/m2.
* By self-assessment, currently performing 60 minutes or less of purposeful exercise per week but able to walk at least 30 minutes on a level surface.
* Access to a smart phone capable of running MyFitnessPal and Garmin Connect apps and willing to have diet and exercise data from these apps viewed by study personnel.
* Live in the greater Kansas City Metropolitan Area
* Willing and able to perform moderate intensity exercise at least 5 days per week for 3 months.
* Willing to perform unsupervised home exercise for the entire 3 months.
* Willing to participate in a weekly behavioral modification group phone call for 3 months.
* Willing to participate in a controlled dietary intervention with portion controlled meals and partial meal and track food intake and exercise.

Exclusion Criteria:

* Use of metformin, insulin, steroids or weight loss or anti-psychotic drugs within the prior 3 weeks
* Individuals with prior bariatric surgery procedures
* Need for chronic immunosuppressive drugs
* Participation within the past 6 months on a structured weight loss program such as Weight Watchers®
* Physical impairments (bad hip, knees, feet, peripheral neuropathy) that would prohibit performing moderate intensity exercise at least 5 days per week.
* Any other condition or intercurrent illness that in the opinion of the investigator makes the subject a poor candidate for participation in the trial such as recent cardiac event.
* Currently receiving investigational agents in a clinical trial.