Inclusion Criteria:  Patients with pathologically proven DCIS or invasive breast cancer histologies Willing and able to provide informed consent Willing and able to comply with study treatments including dietary intervention Body mass index (BMI) >= 21 at time of enrollment  Age >= 40 years at time of consent  * Patients with triple negative breast cancer (TNBC) must be >= 50 years of age at time of consent  Karnofsky performance status (KPS) score 70 - 100 Tumor size =< 3.0 cm  Gross disease within the breast must be unifocal  * Gross disease may be multifocal as long as the total extent of tumor, gross and microscopic, occupies a volume with greatest dimension =< 3 cm  Patients with invasive disease are required to have axillary staging including axillary ultrasound (US) that proves patient is clinically node negative Patient is not being considered for preoperative chemotherapy Must be English or Spanish speaking  Exclusion Criteria:  Patient is clinically node positive: clinically suspicious axillary lymph node(s) by axillary US or exam unless biopsied and found to be negative  Patient has stage IV metastatic disease  * Patients with oligo-metastatic disease who are being treated with curative intent per the treating physician will not be excluded if all other eligibility criteria are met  Breast tumor size is > 3.0 cm Positive non-axillary sentinel nodes or evidence of suspicious supraclavicular, infraclavicular, or internal mammary nodes by imaging or physical exam, unless biopsied and found to be negative for tumor Evidence by physical examination or mammography of other suspicious masses, densities, or microcalcifications in either breast, unless biopsied and found to be benign Paget's disease of the nipple Previous breast radiation on ipsilateral side Any prior treatment with radiation therapy or chemotherapy for the current breast cancer diagnosis prior to registration Patients with significant psychiatric illness that would preclude them from adhering to the protocol in the judgement of the treating clinician BMI < 21 at the time of study enrollment