Fasting-mimicking Diet Intervention on Side Effects of Aromatase Inhibitors Treatment in Patients With Breast Cancer

Inclusion Criteria: * Age ≥ 18 years * WHO performance status score 0-2 * Early stage breast cancer, ER positive, receiving an adjuvant endocrine treatment with aromatase inhibitor * Hypercholesterolemic (total cholesterol \>200mg/dL) * Ongoing treatment with aromatase inhibitors (at least six months of drug exposure) * Adequate renal, hepatic, and hematopoietic function * Written and informed consent for biomaterial submission and participation in the clinical trial * Compliance with treatment and follow up protocol * No other investigational agent may be administered concurrently to patients enrolled in this trial * Patients with skeletal pain are eligible if bone scan and/or RX examination fails to disclose metastatic disease * The interval between the onset of systemic adjuvant therapy with AIs and the randomization should be at least 6 months * Patient is accessible geographically for follow-up and must be able to provide dietary data via telephone recalls * Must be medically able to accept either dietary supplementation group prior to randomization. Exclusion Criteria: * Underweight (BMI \< 18.5 kg/m2) * Current or past eating disorders identified with the SCOFF Questionnaire (Useful Eating Disorder screening questions) \[19\] * Malnutrition Universal Screening Tool (MUST). It considers body mass index, weight change and acute disease effect equally and determines a malnutrition risk score. A score ≥1 identify a patient at moderate risk of malnutrition; * Treatment with any investigational or non-registered drug other than the study product(s) within 30 days preceding the first dose of study product, or planned use during the study period * Use of statins or supplements similar to statins (e.g red rice) or other drugs that interfere with lipid absorption (e.g ezetimibe) * Known to have difficult-to-control hypertension, coronary artery disease, arrhythmia requiring treatment, clinically significant valvular disease, cardiomegaly on chest X-ray, ventricular hypertrophy on ECG, previous myocardial infarction, or congestive heart failure Patients with diabetes are not eligible for the study * History of allergic reactions likely to be exacerbated by any component of the investigational product used in the study * Other concurrent, severe medical problems, unrelated to the malignancy, that would significantly limit full compliance with the study or expose the patient to unacceptable risk * Previous or concomitant malignancies at other sites, except effectively treated malignancy that is considered by the Investigator to have been cured * Psychiatric or addictive disorders that may compromise the ability to give informed consent or to comply with study procedures.