4:3 Intermittent Fasting Intervention in Adults With Breast Cancer and Overweight or Obesity

In order to be eligible to participate in this study, an individual must meet all of the following criteria: * Age 18-65 years * Body Mass Index 25-45 kg/m2 * Diagnosis of stage 1-3 breast cancer within the past 10 years with completion of standard of care definitive surgery, adjuvant chemotherapy, radiation, immunotherapy and/or targeted therapy as appropriate prior to the intervention start date. Completion of definitive surgery must be ≥ 3 months prior to the intervention start date, other therapies must be completed ≥ 1 month prior to the intervention start date (however exceptions to this 1-month timeframe for completion of other therapies can be made on a case-by-case basis by the PI if patients are tolerating therapy without adverse effects and will have completed treatment prior to the intervention start date). Current/ongoing use of anti-endocrine directed therapy for breast cancer (including ovarian suppression, tamoxifen, aromatase inhibitors, selective estrogen degraders) is acceptable as long as participants have been on therapy for ≥3 months prior to the intervention start date. * Live or work within 30 miles of the AHWC (exceptions may be made at the discretion of the Study PI on a case-by-case basis for highly motivated subjects). * Capable and willing to give informed consent and understand exclusion criteria, willing to attend weekly small group sessions held by a registered dietitian, and attend one in person BfitBwell exercise sessions per week. * Have a …