Evaluation of a 12-Week Mediterranean Diet-Based Nutritional and Educational Programme for Breast Cancer Survivors: Impact on BMI, Fatigue, Dietary Adherence, and Menopausal Symptoms

Isabel White¹Rachel Rawson¹Jo Cunningham²Sofia Georgopoulou³Ella Thilaganathan¹Laura Tilt⁴Matthew R D Brown^1,3*

• ¹Percihealth, London, United Kingdom
• ²Green Light Nutrition, London, United Kingdom
• ³Royal Marsden Hospital, London, United Kingdom
• ⁴Field Doctor Ltd, Weston Super Mare, United Kingdom

Breast cancer survivors commonly experience persistent symptoms after treatment. These include weight gain, fatigue, and menopausal symptoms, alongside an increased risk of long-term morbidity, including cardiovascular disease, bone loss and gut microbiome alterations. Maintaining a healthy diet is challenging due to treatment-related metabolic changes, fatigue, and dietary confusion. This research assessed the impact of a 12-week Mediterranean diet-based intervention, incorporating structured frozen meal provision and an online educational programme in breast cancer survivors.Outcomes evaluated included BMI, dietary adherence, fatigue, and menopausal symptoms.Additionally, bone, gut, and cardiovascular health within the context of survivorship was considered.A pre-post intervention evaluation design was employed. 72 participants were enrolled, with 46 completing the full intervention and post-programme evaluation. The intervention comprised weekly delivery of Mediterranean diet-based frozen meals providing key nutrients. A concurrent online educational programme covered topics related to a bio-psycho-social approach to cancer rehabilitation. Primary and secondary outcomes were assessed pre-and post-intervention, educational programme engagement and adherence to meal provision were also evaluated.Following the intervention, BMI decreased from 26.9 to 26.3 kg/m² (p < 0.001). Participants classified as having a healthy BMI increased from 50% at baseline to 52.2%, while the proportion classified as overweight or obese decreased from 50% to 47.8%. Mediterranean diet adherence significantly improved, with mean MEDAS scores increasing from 6.7 at baseline to 7.9 (p < 0.001). The proportion of participants with high adherence to the Mediterranean diet doubled from 8.7% to 17.4%.Menopausal symptoms significantly improved, mean scores decreasing from 23.5 at baseline to 17.5 (p < 0.001), and the prevalence of moderate symptoms reduced from 82.6% to 63%. Fatigue levels did not change significantly (p = 0.37). Subjective feedback from 28% of participants indicated perceived improvements in energy levels, citing increased consumption of fibre, omega-3 fats, and fermented foods as contributing factors. Educational programme engagement varied; 89% of participants accessed at least one module, while 40% completed all modules. Adherence to the meal provision component was high, with 79% of participants consuming at least 75% of the provided meals. The findings highlight the potential for dietary interventions to address key survivorship concerns.