RESUMEN
Background: Obesity is an independent prognostic factor and is associated with poorer response to oncological treatment of breast cancer. Obesity is associated with shorter overall survival and shorter time to recurrence. Material and methods: The study included 104 breast cancer patients qualified for neoadjuvant chemotherapy. The control group consisted of 40 patients who refused to participate in the study. Consultation before chemotherapy included: author's diet questionnaire, body composition analysis, nutrition education. After chemotherapy, the effects of the first dietary advice were evaluated. Results: More than half of all women had a BMI above normal before treatment. Analysis of the effects of nutrition education showed a significant improvement in body composition. After education, a slight increase in body weight and a significant decrease in fat mass and fat percentage were observed. In women who did not participate in education, a statistically significantly greater increase in body weight after chemotherapy was noted. Nutrition education of the study group did not prevent adverse changes in lipid profile resulting from chemotherapy. Conclusions: Dietary counselling prior to neoadjuvant chemotherapy may limit weight gain and may also influence fat mass reduction. Implementation of dietary recommendations does not guarantee maintenance of normal lipid parameters during chemotherapy.