The main aim of this study is to determine the effect of a multimodal intervention (Nutrition and Exercise) on quality of life, emotional well-being, and secondary symptomatology in patients diagnosed with breast cancer during neoadjuvant chemotherapy treatment, and to compare them with the control group.

Multiple studies have demonstrated the relationship between obesity, sedentary lifestyle and stress on the risk of developing various types of cancer, including breast cancer. The correlation between a high Body Mass Index (BMI) and a worse prognosis in patients already diagnosed with breast cancer has also been studied, as well as the tendency to gain weight during chemotherapy treatments. A low-fat dietary pattern has been associated with reduced mortality after a breast cancer diagnosis, through mechanisms that decrease the likelihood of developing metabolic syndrome and reduce estradiol levels. In recent years, the importance of healthy lifestyle habits in improving the quality of life of these patients has also been demonstrated.

Although BMI is an easy-to-obtain marker of obesity, it is a rather crude measure that does not fully reflect the dysfunctional activity of visceral fat (VAT), which appears to be a key pathophysiological mechanism determining the clinical and metabolic consequences of obesity. Recent studies demonstrate an association between increased metabolic activity of VAT, determined preoperatively by 18F-FDG PET/CT, with the presence of metastatic axillary lymph node involvement in postmenopausal patients with luminal breast cancer.

The current study is proposed during neoadjuvant treatment (NY), and aims to determine whether after an intervention in exercise and diet improves the quality of life of patients and tolerability to oncological treatment NY. In addition, the investigators will use 18F-FDG PET/CT as a marker of aggressiveness at diagnosis by quantifying the metabolic activity of VAT (SUVmax VAT, SULmax VAT and VAT/SAT ratio) and subsequently in the assessment of response to treatment. The investigators will also determine the response at the histopathological level of the tumor itself after the intervention (residual tumor burden (RCB), Ki 67, TNM) and at the level of inflammation-related parameters (TNF, IL6, CRP), which can influence the prognosis and the risk of local or distant recurrence in patients.

Inclusion Criteria:

• Patients diagnosed with breast cancer who will undergo neoadjuvant treatment in the Oncology Unit of the Virgen de las Nieves University Hospital of Granada.
• Aged between 18 and 75 years.
• Give their consent to participate in the study and commit to complete the entire intervention and attend their follow-up appointments.
• Participant must be capable and willing to provide consent, understand exclusion criteria, instructions and protocols

Exclusion Criteria:

• Patients who are unwilling or unable to comply with the established guidelines by means of an intervention in diet and physical exercise and/or who present physical or psychological pathologies that contraindicate their inclusion in the study.
• Patients who do not register the data required for follow-up.
• Any condition that, in the investigator's opinion, impairs the ability to participate in the study or represents a personal risk for the participant.
• Are deemed unsuitable by the investigator for any other reason, that prevent data collection.