Cancer Survivors With Obesity Want Weight Support but Miss the Risk Link

For the millions of people living with and beyond a cancer diagnosis, the question of what to do about body weight is far more complicated than a simple instruction to eat less and move more. A new qualitative study published in BMC Cancer has explored how people who have been treated for breast, colorectal or prostate cancer, and who have lived experience of obesity, think about their weight, their health behaviours, and the kind of support they would actually want from the health system. The findings reveal a striking gap between what patients want and what they currently receive, alongside widespread misunderstanding of one of the most important modifiable risk factors for cancer outcomes.

The research team, led by Kelly E. Lloyd of the Leeds Institute of Health Sciences at the University of Leeds, together with colleagues from University College London and the University of Surrey, conducted semi-structured, one-to-one telephone interviews with 19 adults. All participants had previously reported a body mass index of 30 or above, the clinical threshold for obesity, and all had received a diagnosis of breast, colorectal or prostate cancer. Rather than recruiting from the general population, the researchers drew their sample from two existing randomised trials, ASCOT and APPROACH, both of which were designed to improve health behaviours among people diagnosed with cancer. This recruitment strategy meant that every participant was already engaged to some degree with research on lifestyle and cancer, yet the interviews still uncovered substantial gaps in knowledge and considerable ambivalence about weight-related messaging.

The time since diagnosis among participants ranged widely, from nine months to 133 months, meaning the study captured perspectives from people in the midst of primary treatment as well as those many years into survivorship. The researchers analysed the interview transcripts using reflexive thematic analysis, a qualitative method in which researchers actively examine how their own assumptions and positionality shape the interpretation of data, rather than pretending to a purely mechanical extraction of themes. This approach is well suited to sensitive topics such as body weight, where stigma, shame and personal history all colour what participants are willing to say and how their accounts should be understood.

Three overarching themes emerged from the analysis. The first concerned the varied experiences of weight change after cancer and the equally varied responses to those changes. Most participants reported a common trajectory: their weight decreased during primary treatment, often because of treatment side effects, changes in appetite or the physical demands of therapy, but then crept back to pre-diagnosis levels once treatment ended. Participants held mixed views on whether the cancer itself had influenced their weight in any lasting way. For some, the diagnosis had been a moment of reflection that prompted healthier habits; for others, the disruption of treatment had derailed routines around food and physical activity in ways that proved difficult to reverse. The heterogeneity of these accounts is itself an important finding, because it suggests that no single narrative about cancer and weight will resonate with every survivor.

The second theme is perhaps the most consequential for public health: misperceptions of the relationship between weight and cancer risk. Most participants were simply unaware that obesity is linked to poorer cancer outcomes, including increased risks of mortality and morbidity after a diagnosis. Evidence from large epidemiological studies has consistently associated obesity and weight gain after diagnosis with worse prognosis across several cancer types, which is precisely why weight management is considered a legitimate component of survivorship care. Yet when this link was raised in the interviews, a number of participants were actively resistant to the message. Some questioned whether weight could really matter for their particular cancer, while others bristled at what they perceived as blame or judgement. This resistance matters clinically, because a health message that triggers defensiveness is unlikely to produce sustained behaviour change, and it highlights the delicate communication task facing oncologists, nurses and general practitioners.

Despite the scepticism about the weight-cancer connection, the third theme offered grounds for optimism. Most participants wanted to lose weight for general health reasons, independent of any cancer-specific motivation, and many felt that it would be beneficial for healthcare professionals to discuss weight management once primary cancer treatment had ceased. In other words, the appetite for support exists; what is missing is a system that delivers it at the right moment. Participants suggested that the end of active treatment represents a natural window of opportunity, a point at which attention shifts from surviving the disease to living well afterwards, and when patients may be most receptive to conversations about long-term health. At present, that window frequently closes without anyone raising the subject of weight at all.

The question of whether weight management programmes should be specifically tailored for people living with and beyond cancer divided the participants. Those in favour of tailoring pointed to two main benefits. First, targeted advice could address the particular physiological and practical challenges that cancer survivors face, such as treatment-related fatigue, lymphoedema, changes in body composition, or the psychological aftermath of a diagnosis, all of which can make generic diet and exercise programmes harder to follow. Second, a cancer-specific programme could provide increased social support by bringing together people with shared experiences, reducing the isolation that many survivors report. On the other side, some participants felt that weight management advice is fundamentally universal, applying equally to everyone regardless of medical history, and that creating separate programmes for cancer survivors might be unnecessary or even stigmatising. This split reflects a genuine design tension for service planners: tailored interventions tend to perform better in trials, but they are more expensive to develop and deliver, and some patients may prefer not to have their cancer identity foregrounded in yet another aspect of their care.

From a technical standpoint, the study’s methodology carries both strengths and limitations that readers should weigh. The use of telephone interviews widened geographic reach and may have made participants more comfortable discussing a stigmatised topic from their own homes. Reflexive thematic analysis, as employed here, is a recognised and rigorous approach within health services research, and the triangulation of findings across two parent trials strengthens confidence that the themes are not artefacts of a single recruitment context. However, 19 participants drawn from trials of health behaviour change cannot represent the full diversity of the cancer survivor population, and the fact that all participants had a BMI of 30 or above means the findings speak specifically to people with lived experience of obesity rather than to survivors across the weight spectrum. The sample was also restricted to three cancer types, breast, colorectal and prostate, which are among the most common but are not representative of all malignancies. Qualitative work of this kind is not designed to quantify prevalence; its value lies in generating hypotheses and illuminating mechanisms that can then be tested in larger studies and intervention trials.

The implications for clinical practice are nonetheless clear. Obesity and weight gain after a cancer diagnosis are associated with poorer outcomes, and weight management could help reduce the risk of both mortality and morbidity in this growing population. The study suggests that people with excess weight who are living with and beyond cancer desire more weight management support than they currently receive, that tailored programmes could be developed to meet this demand, and that healthcare professionals may be best placed to introduce such support once primary cancer treatment has ceased. The authors’ work was funded by Cancer Research UK and Yorkshire Cancer Research, with additional fellowship support from the Economic and Social Research Council, and the funders had no influence on the data collection, interpretation or reporting. The article is published open access under a Creative Commons Attribution 4.0 licence, making the full interviews analysis freely available to clinicians, researchers and patients alike.

What makes this study resonate beyond its immediate field is the light it sheds on a universal problem in preventive medicine: information alone does not change behaviour, and messages that ignore patients’ lived experiences can actively backfire. Cancer survivors in this study were not indifferent to their weight; most wanted to lose it and believed their doctors should help. What they lacked was an accurate understanding of why weight matters for cancer outcomes, and a service designed around the realities of life after treatment. Closing that gap will require oncology teams to be trained and incentivised to have weight conversations at the right time, in the right way, and with programmes that respect the choice between cancer-specific and universal support. As the population of cancer survivors continues to grow worldwide, the findings offer a practical, evidence-based starting point for building survivorship care that treats weight management not as an afterthought, but as an integral part of recovery.

Subject of Research: Weight management views and support needs among adults living with and beyond cancer who have experience of obesity

Article Title: Views on weight management among adults living with and beyond cancer, who have experience of living with obesity: a qualitative study

Article References: Lloyd, K. E., Kennedy, F., Joshi, V., Fisher, A., Beeken, R. J., & Lally, P. (2026). Views on weight management among adults living with and beyond cancer, who have experience of living with obesity: a qualitative study. BMC Cancer. https://doi.org/10.1186/s12885-026-17136-2

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17136-2

Keywords: cancer survivorship, weight management, obesity, qualitative research, thematic analysis, breast cancer, colorectal cancer, prostate cancer, health behaviours, patient support, BMC Cancer, risk perception