Associação dos parâmetros crononutricionais com a qualidade da dieta e estado nutricional em mulheres submetidas à quimioterapia e terapia endócrina com tamoxifeno para o câncer de mama

Abstract

Introduction: Studies have suggested that not only how much you eat, but also variables related to meal timing and eating frequency contribute significantly to the diet quality, body weight regulation and energy balance. However, so far, these studies were not conducted with female breast cancer (BC) undergoing systemic treatments, such as chemotherapy (CT) and adjuvant endocrine therapy with tamoxifen, which are important antineoplastic treatments that can have negative adverse effects on food consumption and nutritional status. Objective: This thesis had two main objectives: 1) To examine the association of the number of eating episodes with the diet quality and nutritional status in women with BC at three moments of the CT (T0: period before the administration of the first cycle of CT; T1: period after the administration of the intermediate cycle of CT; T2: period after the administration of the last cycle of CT); 2) To examine the associations of the number of eating episodes and meal timing with the quality and quantity of the diet, anthropometric and body composition parameters in women undergoing endocrine therapy with tamoxifen for BC. Material and Methods: The first manuscript in this thesis is a prospective study conducted with 55 BC women undergoing CT. Dietary data were obtained through nine 24-hour recalls (24HR) and diet quality was assessed using the Brazilian Healthy IndexRevised (BHEI-R) at T0, T1, and T2. Anthropometric measurements were obtained at at the three moments. The eating frequency was determined by the median value, obtained through the mean of the number of daily eating episodes of three R24H for each time of the study. The second manuscript in this thesis is a cross-sectional study conducted with 84 women undergoing endocrine therapy with tamoxifen for BC. Dietary data were obtained by three R24H and the diet quality was assessed using the BHEI-R. Participants were classified as early or late eaters by the median time of food consumption at breakfast, lunch, and dinner, as well as considering the middle time point between the first and last meal of the day. The median value of eating frequency was obtained through the mean of the number of daily eating episodes by three R24H. Anthropometric measurements and body fat percentage, using the electrical bioimpedance, were investigated. Results: Both studies (Manuscript1 and Manuscript 2) suggeststhat a higher daily eating frequency was associated with better diet quality. Early eaters were also associated with better diet quality and lower daily energy consumption in women undergoing endocrine therapy with tamoxifen for BC. In addition, in those women undergoing CT, an inverse association was observed between eating frequency and anthropometric parameters at T0. Conclusion: A higher eating frequency and earlier consumption of eating episodes of the day may be a strategy to help improve the diet quality in women undergoing systemic treatments for BC, considering the adverse impact on these patients' health. Confirmation of these results is important for the inclusion of this approach in nutritional guidelines for cancer patients.