INTRODUCTION: There has been an increase in the incidence of breast cancer cases in the last decade, and despite the treatment increasing the chances of survival, it reduces the quality of life. In this context, diets could decrease the adverse effects of treatment and improve quality of life. METHODOLOGY: A form with the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire, which contains specific scores for physical, cognitive, emotional, symptomatic, and functional performance, was made available in a Facebook support group. Afterward, the data were analyzed using linear regression and a t-test of independent samples using Jamovi version 2.3.24 (retrieved from https://www.jamovi.org). RESULTS: There was a low number of participants who followed the ketogenic diet or intermittent fasting. In general, adherence to the diets was good. In the t-test, diets showed improvement in physical performance. Linear regression correlated treatment with chemotherapy, metastases, and bad diet adherence with worse symptomatic scores. CONCLUSION: There is evidence that diets can improve the symptoms of these patients; however, there is no consensus about which diet produces the best effect, requiring further studies on this subject.
