DIetary REstriction as an Adjunct to Neoadjuvant ChemoTherapy for HER2 Negative Breast Cancer

Inclusion Criteria: * Female patients with stage II or III (cT1cN+ or ≥T2 any cN, cM0) breast cancer receiving neoadjuvant AC-T * Measurable disease (breast and/or lymph nodes) * HER2 negative core biopsy Age ≥18 years * WHO performance status 0-2 * Adequate bone marrow function : white blood cells (WBCs) ≥3.0 x 109/l, neutrophils ≥1.5 x 109/l, platelets ≥100 x 109/l * Adequate liver function: bilirubin ≤1.5 x upper limit of normal (UNL) range, ALAT and/or ASAT ≤2.5 x UNL, Alkaline Phosphatase ≤5 x UNL * Adequate renal function: the calculated creatinine clearance should be ≥50 mL/min * Patients must be accessible for treatment and follow-up * Written informed consent according to the local Ethics Committee requirements * Willing to fill in quality of life questionnaires * Able to read and write in Dutch Exclusion Criteria: * History of breast cancer (invasive or non-invasive) * Previous malignancy within 5 years, with exception of a history of a previous basal cell carcinoma of the skin or pre-invasive carcinoma of the cervix. * Serious other diseases such as recent myocardial infarction, clinical signs of cardiac failure or clinically significant arrhythmias * Diabetes Mellitus * Body mass index (BMI) \< 19 kg/m2 * Pregnancy or lactating * Significant food allergies which would make the subject unable to consume the food provided (ex: nuts or soy) * Any metabolic disorders that may affect gluconeogenesis or adaptation to short fasting periods. * Medical or psychological condition which in the opinion of the investigator would not permit the patient to complete the study or sign meaningful informed consent