The PI is leaving Duke for a position in another state.

The objective of this study is to evaluate intermittent fasting after the treatment of breast cancer with surgery and radiation therapy. All participants will either delay their first meal of the day or advance their last meal to achieve an approximate 16-18 hour fasting period four times per week. Over six months, the innovative protocol will 1) assess adherence, and is expected to 2) improve body composition, quality of life and inflammatory and metabolic variables linked with outcomes after breast cancer treatment. The long-term goal of this project is to incorporate this dietary strategy as a standard component of care for breast cancer patients.

Inclusion Criteria:

• biopsy proven diagnosis of ductal carcinoma in situ or invasive carcinoma of the breast stage I-III
• completed any chemotherapy prior to initiation of the trial (adjuvant endocrine therapy is permitted)
• BMI > 25 kg/m2 or body fat% greater or equal to 31%
• have a schedule amenable to nutrition and dietitian counseling described within the study protocol as determined by the treating radiation oncologist
• have access to the internet and email with capability to join Zoom calls

Exclusion Criteria:

• Metastatic breast cancer
• Currently receiving chemotherapy
• Uncontrolled hypertension or diabetes, defined as systolic blood pressure over 149, diastolic blood pressure over 99, or hemoglobin A1c greater than 8.9.
• Diabetic condition requiring the usage of insulin

participant eligibility is not based on self-representation of gender identity