Objective: The purpose of this study was to evaluate the occurrence of the metabolic syndrome and obesity during the first year after the diagnosis of breast cancer in women undergoing interdisciplinary approach. Methods: In this prospective study, 81 women (age ≥45 years) with recent histological diagnosis of breast cancer, no established cardiovascular disease, who attended at a single specialized center with an interdisciplinary approach (medical, nutritionist, and psychological) were included. Results: Women with metabolic syndrome were considered to have three or more diagnostic criteria: waist circumference >88 cm, triglycerides 150 mg/dL, high-density lipoprotein <50 mg/dL, blood pressure 130/85 mmHg, and glucose 100 mg/dL. Obesity was considered when body mass index >30 kg/m2 and abdominal obesity with waist circumference >88 cm. The evaluations were carried out at three time points: first cancer visit (T0m), 6 months (T6m), and 12 months (T12m). For statistical analysis, the McNemar test was used to compare these time points and the chi-square test was used for trends. The mean age of the patients was 58.410.7 years, and 83.3% of them were in the postmenopausal stage. There were no differences in the metabolic syndrome, body mass index, and waist circumference assessments at the indicated time points. When comparing the individual quantitative criteria for metabolic syndrome, there was a statistically significant difference in the values of triglycerides and blood glucose. At times T0m, T6m, and T12m, an increase in the mean triglyceride values was observed, 121, 139.4, and 148.46 mg/dL (p=0.003) and a reduction in the mean glucose values, 106.6, 100.46, and 98.96 mg/dL (p=0.004), respectively. Conclusion: Women with breast cancer subjected to interdisciplinary evaluation did not show an increase in the occurrence of metabolic syndrome and obesity during the first year following their cancer diagnosis.