The nutritional specification brief for the meal range was developed based on recommendations from the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) and the Continuous Update Project (CUP) Global reports (27). As these reports included studies published up to 31 October 2021, a literature review was conducted to identify relevant research published from 1 November 2021 to 30 September 2023. This encompassed the search terms: “Diet, Food, and Nutrition, Micronutrients, Gastrointestinal Microbiome, Nutrition Therapy, nutritional intake, dietary or food choice and breast neoplasm, breast cancer and mortality, cancer survivorship, cancer survivors.”

The initial search retrieved 1,593 papers 270 duplicates were removed leaving a total of 1,323 articles for title and abstract screening. After full-text assessment, 53 studies met inclusion criteria and were used to directly inform the meal design process.

Studies were included if they:

Studies were excluded if they:

A PRISMA flow diagram detailing the literature review process is provided in the Supplementary materials.

Educational Programme of Care modules were developed by Perci Health's clinician team comprising a breast cancer nurse specialist, weight management specialist dietitian, mindfulness practitioner and oncology exercise coach led by an oncology specialist dietician. The programme aimed to educate and support individuals after breast cancer treatment by providing evidence-based dietary and lifestyle guidance. Content aligned with the latest guidelines and with current evidence related to nutrition, exercise, weight management, and psychological wellbeing (55, 56).

The programme was structured into nine core modules, each addressing key aspects of diet, wellbeing, and lifestyle interventions post-breast cancer treatment. The content was uploaded into a programme designed by Perci Health, using a modular format to allow flexible engagement and tracking. Each module incorporated video-based education, written resources, and practical application components. Module content is outlined in Table 1.

The 12-week intervention phase comprised two components: frozen ready meal provision and online educational support.

Field Doctor was responsible for the production and delivery of meals, which were, frozen and in insulated packaging and delivered weekly to participants' homes with detailed nutritional information and instructions.

The online educational programme was delivered via Perci Health's interactive online platform, with content available on-demand, allowing participants to access the content at their convenience.

Adherence was monitored through self-reported meal logs and module completion rates assessed via platform metrics. Participants recorded the number of intervention-provided meals consumed each week. Adherence was defined as the consumption of at least 75% of the provided meals during the 12-week intervention.

The primary outcome was the change in BMI from baseline to post-intervention. BMI was calculated using self-reported height and weight and classified according to World Health Organization (WHO) criteria.

Secondary outcomes included changes in dietary adherence, menopausal symptoms, and fatigue levels. Dietary adherence was assessed using the Mediterranean Diet Adherence Screener (MEDAS), a 14-item questionnaire assessing the frequency of key Mediterranean dietary components (57). Menopausal symptoms were evaluated using the Menopause Symptom Checklist [derived from the Greene Climacteric Scale (GCS)]. Participants rated 21 symptoms, grouped into the following subscales: psychological symptoms (11 items), somatic symptoms (7 items), vasomotor symptoms (2 items) and sexual dysfunction (1 item) (58). Fatigue levels were assessed using a validated fatigue scale, with higher scores indicating greater fatigue severity (59).

Statistical analyses were conducted using IBM SPSS v.29 (IBM Corp: Armonk, NY Corp). Paired t-tests compared pre- and post-intervention means. Pearson's correlation coefficients were calculated to explore associations between changes in dietary adherence and symptom improvement. Multiple regression analyses were conducted to control for potential confounders such as age, BMI, and treatment history. Missing data were addressed through pairwise deletion, with sensitivity analyses performed to assess potential biases. Paired t-tests were chosen to compare pre- and post-intervention outcomes within the same group, as the study design did not include a control group. A significance level of p < 0.05 was applied for all analyses.

From a pool of 119 eligible participants, a total of 85 participants completed the initial demographic survey, with 72 (84.7%) enrolling in the intervention. Of these, 46 (63.8%) participants completed the full 12-week programme and post-intervention evaluation. An additional 10 participants completed the 12-week meal and education programme but did not return the final survey, these individuals were not included in the analysis.

All participants were women aged 30 to 75 years, with a history of primary breast cancer (Stages I–III) and having completed primary treatment, including surgery, chemotherapy, and/or radiotherapy.

80.6% of participants identifying as White British. Limited representation was seen from South Asian (4.2%), Black (4.2%), and other ethnic minority groups (11%).

At baseline, the mean BMI was 26.9 kg/m². Among participants completing the full programme baseline mean BMI was 27.8 kg/m² with 50% having a healthy BMI (18.5–24.9 kg/m²), 32.5% classified as overweight (BMI 25–29.9 kg/m²), and 17.5% classified as obese (BMI ≥30 kg/m²). Results are summarized in tabular form in the Supplementary materials.

Engagement with the online educational programme varied. Among the full sample (n = 72), 89% accessed at least one module, while 40% completed all modules. Of the 46 participants who completed the programme and post-programme evaluation, 96% accessed at least some content, but only 46% completed all modules.

Module engagement was highest for introductory content on goal setting and myth-busting (93%) but declined for later modules, particularly those addressing side effect management (59%), psychological wellbeing (59%), and physical activity (67%). The final module on long-term habit maintenance had the lowest engagement (46%).

Participants reported improved confidence in managing diet and wellbeing following the educational course, with confidence scores increasing by 20%. Post-programme surveys indicated that participants felt better equipped to navigate nutrition-related decisions and were more likely to seek reliable information from qualified professionals. Additionally, understanding of common cancer nutrition myths improved by 30%, with participants specifically mentioning increased clarity around soy, dairy, and sugar consumption.

Adherence to the meal provision component was high, with 79% of participants consuming at least 75% of the provided meals during the intervention period. Participants valued the convenience of the meal provision, particularly in reducing decision fatigue and supporting dietary adherence. However, some participants found it challenging to integrate the meals into family eating routines, while others desired more flexibility in meal selection.

Free-text responses provided further insight into participant experiences with the educational component. Many found the information clear and useful, particularly in dispelling common nutrition myths. However, barriers to engagement included time constraints, perceived repetition of previously known information, and a preference for live or interactive elements. Some participants suggested allowing modules to be accessed in any order, integrating a digital tracking feature, and providing downloadable reference materials to improve accessibility and engagement.

Participants generally found the meal provision aspect highly convenient and supportive of their dietary goals. However, qualitative feedback indicated areas for improvement.

Some participants expressed a desire for greater meal variety, particularly for pescatarian and vegetarian options. Others found portion sizes too large, making it difficult to balance them with family meals. Some meals were perceived as too carbohydrate-heavy or lacking in texture, while others suggested that clearer cooking instructions and guidance on incorporating additional vegetables would enhance the experience. Concerns regarding meal packaging sustainability and food safety, particularly regarding the plastic film used on trays, were also raised.

These findings suggest that while meal provision was effective in supporting adherence, modifications to meal diversity and household integration strategies may further improve long-term acceptability and adoption.

The reduction in BMI observed in this study (from 26.9 kg/m² to 26.3 kg/m², p < 0.001) aligns with previous research demonstrating the benefits of Mediterranean dietary patterns for weight management (2, 5). Post-diagnosis weight gain is common among breast cancer survivors, with studies indicating that up to 96% of survivors experience some degree of weight gain post-treatment (3). Factors contributing to this include metabolic changes, reduced physical activity, and dietary shifts influenced by treatment side effects and psychological distress.

The calorie-controlled ready meal and snack pots were designed to prioritize fiber, plant-based proteins, and healthy fats. Research suggests that adherence to a Mediterranean diet promotes satiety, stabilizes blood glucose levels, and modulates inflammatory responses, all of which may support weight management (60, 61). However, effective weight management is not solely driven by dietary composition but also by behavioral and lifestyle factors (62).

Engagement with the weight management module in the educational programme was 78%, while engagement with the exercise module was 67%. Although the majority of participants accessed content related to dietary strategies for weight management, the lower engagement with exercise-related materials may have influenced weight-related outcomes.

Post-programme survey responses indicated that confidence in diet and nutrition strategies for weight management increased by 20%, and knowledge regarding the impact of body weight on breast cancer outcomes also improved by 20%. However, despite this increase in knowledge, qualitative feedback highlighted that some participants found it challenging to balance meals with their usual dietary habits and required additional flexibility in meal selection.

Consideration should be made as to how structured dietary support can be adapted for long-term sustainability. This may include offering more flexible meal selection options, integrating behavioral coaching on self-prepared meals, and assessing whether Mediterranean diet adherence is maintained after the intervention period. Additionally, interventions could benefit from including a more structured physical activity component, particularly given its role in maintaining metabolic health, supporting weight regulation, reducing inflammation, improving mental health, and potentially enhancing fatigue outcomes in cancer survivors (63–65). Strategies to enhance engagement with exercise guidance could include structured physical activity tracking or interactive movement-based content.

Common barriers to dietary adherence of nutrition interventions include confusion, overwhelm, misinformation, fatigue, cultural food traditions, and lack of time (66, 67). The combination of meal provision and educational support in this study appears to have addressed these challenges. The significant increase in MEDAS scores from 6.7 to 7.9 (p < 0.001) suggests that combining practical meal support with education is an effective strategy for reinforcing Mediterranean dietary principles.

The meal provision component minimized time-related barriers, as participants did not need to engage in extensive meal planning or preparation. Additionally, the educational programme helped combat misinformation, as evidenced by a 30% increase in participant understanding of key nutrition facts, including those related to soy, dairy and sugar. These improvements reflect an increase in dietary confidence, a key predictor of long-term adherence to dietary recommendations (66).

Despite these improvements, some participants expressed a desire for greater flexibility in meal selection and additional guidance on integrating meals into family routines. This suggests that while structured meal provision is highly effective for short-term adherence, long-term sustainability may require additional flexibility and behavioral support. Additionally, by providing meals solely for the participant, adherence may have been compromised. Gradual transition strategies, such as partial meal provision combined with self-prepared meals, may enhance long-term adherence and could be explored in future work.

Menopausal symptom severity significantly decreased following the intervention, with the mean score reducing from 23.5 to 17.5 (p < 0.001). The prevalence of moderate symptoms decreased from 82.6% to 63%, with participants most commonly reporting improvements in hot flushes, night sweats, and mood disturbances. These findings support the growing body of literature suggesting that interventions may help alleviate menopausal symptoms (14, 15). Key components included in the dietary intervention such as soy isoflavones, have been shown to exert mild oestrogenic effects, which may help modulate vasomotor symptoms such as hot flushes and night sweats (68–70). In addition, the meal range aimed to include omega-3 fatty acids which have been linked to reductions in inflammation and hormonal fluctuations, potentially contributing to improved symptom management (71). Given the high adherence to Mediterranean diet principles in this intervention, it is likely that these dietary factors played a role in the observed improvement in menopausal symptoms, which supports the existing evidence that this type of dietary pattern is associated with reductions in menopausal symptoms (72).

While the observed reductions in menopausal symptoms are promising, future studies should explore whether symptom relief is sustained beyond the intervention period. It may also be beneficial to consider how increasing engagement with physical activity modules could be beneficial for menopausal symptom management (73, 74).

Despite improvements in diet adherence and weight management, fatigue levels did not change significantly (p = 0.37). This aligns with prior studies indicating that dietary modifications alone may be insufficient to address cancer-related fatigue, a symptom influenced by multiple factors, including inflammation, physical activity levels, sleep quality, and psychological wellbeing (75).

Individual responses, did however, vary substantially. While 45% of participants reported a reduction in fatigue, 47% reported an increase, highlighting the heterogeneity of fatigue experienced by breast cancer survivors. Notably, none of the participants who initially reported extreme fatigue maintained this level post-intervention, indicating that some individuals experienced meaningful improvements despite the lack of statistical significance within the cohort. Conversely, one participant reported a substantial increase in fatigue (from 1 to 8 post-intervention) on the fatigue scale but continued to report 'a little' fatigue on the menopause-related questionnaire. This discrepancy highlights variability in how individuals interpret and report fatigue across different measures.

Engagement with fatigue-related educational content was also variable, 41% of participants did not access the module on managing side effects, which included fatigue-specific strategies. Additionally, engagement with the physical activity (67%) and psychological wellbeing (59%) modules was lower than other modules, despite the well-established role of physical activity, stress management, and sleep optimisation in fatigue reduction (75, 76). Given the importance of multi-component interventions, the low engagement with these elements may have contributed to the lack of significant improvement in fatigue scores.

Another key consideration is the role of micronutrient status and metabolic factors in fatigue. Research suggests that glutamine deficiency, vitamin D insufficiency, and omega-3 fatty acid status may influence fatigue severity (10, 47, 77). Without biomarker assessments in this intervention, it remains unclear whether underlying nutrient deficiencies contributed to fatigue persistence. Future interventions should consider personalized supplement recommendations based on biomarker testing to determine whether targeted interventions could further support fatigue reduction in this population.

To optimize engagement and intervention effectiveness, attempts should be made to integrate structured encouragement mechanisms to increase completion rates for fatigue-related content. Strategies such as interactive features, personalized reminders, or progress tracking systems could help reinforce adherence. Additionally, incorporating guided exercise components and structured physical activity monitoring may better support fatigue management, given the well-established role of movement in reducing cancer-related fatigue.

Finally, future research should explore whether long-term adherence to a Mediterranean diet, particularly when combined with personalized nutritional and behavioral support, leads to progressive improvements in fatigue. As fatigue often persists for years post-treatment, understanding how dietary, physical activity, and psychological interventions can be sustained over time is critical for improving long-term survivorship outcomes in breast cancer survivors.

The limitations of this research should be carefully considered when interpreting the findings. The pre-post design without a control group limits the ability to attribute observed changes solely to the intervention, as external factors may have influenced the results. Future studies should incorporate a randomized controlled trial (RCT) design to strengthen causal inferences and better assess the direct effects of a Mediterranean diet-based intervention in breast cancer survivors. Additionally, adherence data were self-reported, which introduces the possibility of response bias, particularly in dietary intake reporting. Objective measures, such as biomarkers of dietary adherence, may enhance data accuracy in future research.

The lack of biological outcome measures, including serum vitamin D levels, gut microbiome composition, and cardiovascular biomarkers, presents another limitation. While the intervention was designed to support bone health, gut health, and cardiovascular risk reduction, the absence of direct biochemical assessments means that the physiological impact of dietary modifications could not be confirmed. Future research should incorporate biomarker assessments to determine whether dietary changes translate into measurable improvements in these health domains.

Another limitation is the lack of ethnic diversity within the participant cohort. The majority of participants (80.6%) identified as White British, with limited representation from ethnic minority groups. Given that some ethnic minorities have a higher genetic predisposition to weight gain, insulin resistance, and associated cardiometabolic comorbidities, future research should consider targeted recruitment strategies to capture a more diverse population. Recruitment approaches tailored to specific communities, such as collaborating with culturally relevant cancer support organizations, may improve inclusivity and generalisability.

Dietary preferences may have also influenced participation rates among ethnic minority groups. The Mediterranean diet, while well-supported in the literature for its health benefits, may not align with the traditional food preferences or cultural dietary patterns of certain ethnic groups. This could have been a barrier to engagement, particularly if participants perceived the intervention meals as unfamiliar or less suitable to their usual eating habits. Future interventions could adapt Mediterranean diet principles to be more culturally inclusive, incorporating staple ingredients, cooking methods, and flavor profiles that resonate with a broader range of dietary traditions while still aligning with core nutritional targets.

Furthermore, the limited ethnic representation raises questions about potential differences in dietary adherence, metabolic response, and intervention effectiveness across diverse populations. Research suggests that gut microbiome composition, response to dietary patterns, and micronutrient metabolism may vary by ethnicity (90, 91). Future studies should explore whether tailored dietary interventions—such as Mediterranean diet adaptations for South Asian, African, or Middle Eastern populations—result in comparable benefits across different ethnic groups.

Engagement with the educational programme varied, particularly for modules covering fatigue, physical activity, and long-term habit maintenance. Given that fatigue is a multifactorial issue requiring a combination of dietary, behavioral, and lifestyle interventions, limited engagement with content addressing stress management, exercise, and sleep hygiene may have contributed to the lack of significant improvements in fatigue scores. Similarly, engagement with the physical activity module was moderate, despite its relevance for both weight management and bone health. Future interventions should explore strategies to enhance engagement with key educational content, such as incorporating interactive components, structured reminders, or personalized coaching.

Future research should also investigate the long-term sustainability of dietary adherence and health outcomes beyond the 12-week intervention period. A follow-up study assessing whether participants maintain Mediterranean diet principles and whether observed improvements in BMI, menopausal symptoms, and dietary adherence persist over time would provide valuable insight into the long-term impact of structured meal provision combined with education.