Aims: Evidence on the effect of dietary interventions on cancer survival, across cancer types and intervention characteristics, remains inconclusive. The aim of this living systematic review is to provide an open-access, continually updated resource summarising the effect of dietary interventions on cancer survival, and to compare the effect between intervention characteristics.
Methods: Systematic searches of databases and clinical trial registries will be conducted every six to 12 months, with findings published on an open-access platform. The initial search was conducted in October, 2025, and study screening was completed in duplicate. Randomised controlled trials evaluating the effect of behaviour change-focused dietary interventions on survival in people living with cancer were eligible for inclusion. Data extraction, risk of bias and overall evidence quality assessment are currently underway. Random-effects models were used to generate pooled hazard ratio estimates for overall survival and other survival outcomes.
Results: Seven eligible records were identified, reporting on six studies including a total of 1,038 participants (median sample size n=146 (range: 21–358)). Studies included participants with mixed cancer types (n=3), or upper gastrointestinal cancer only (n=3). Three interventions focused on adequate energy (+/- protein) intake, whilst others implemented tailored, symptom-informed advice (n=2), or a ketogenic diet (n=1). All interventions were delivered during active treatment. The median intervention length was 15 weeks (range: 6-18) and median follow up time for survival outcomes was 18 months (range: 6-62). Results from pooled analysis of six studies (n=8 intervention arms) suggests no effect on overall survival through dietary intervention (HR: 0.90, 95% CI: 0.74-1.09).
Conclusions: As more research emerges exploring the role of diet following a cancer diagnosis, this living review will provide a curated, contemporary resource to support ongoing analysis and drive improvements in research, policy and clinical practice.