Weight Management Effectiveness and Predictors of Dropout in Breast Cancer Survivors: A Retrospective Study

Background: Reducing obesity and weight gain, which often occurs during breast cancer treatment, may represent an efficient secondary or tertiary prevention against cancer. Purpose: This retrospective observational cohort study aimed to assess the impact of a Mediterranean diet on weight and anthropometric changes in women completing active breast cancer treatment. Additionally, we sought to identify factors associated with study dropout within one year. Methods: A total of 182 female patients (20 normal weight, 59 overweight, 103 obese) received personalized Mediterranean diet interventions and underwent monthly outpatient visits. Results: Dropout rates were 42.3% at 6 months and 64.1% at 12 months. Among the obese subgroup, BMI (p < 0.001) and fat mass (p < 0.05) decreased after 6 months. At 12 months, the obese subgroup showed a borderline significant further reduction in BMI (p = 0.062). BMI or weight loss did not predict dropout at any time point. However, age (OR = 0.91) and diastolic blood pressure (OR = 1.07) were significant predictors of dropout at 12 months. Conclusion: Implementing a Mediterranean diet can lead to weight and anthropometric improvements in breast cancer survivors. Further research is necessary to explore the long-term effects of weight loss on these individuals, identify effective dietary approaches, and consider specific predictors of dropout.