Assessing the feasibility of dietary restriction, including short-term fasting, at the time of chemotherapy

Abstract

Background
Dietary restriction may help protect non-tumour cells from chemotherapy toxicity by allowing them to conserve energy for maintenance/repair. Most of the research to date has been conducted in cell line/animal models and efficacy of interventions in humans is not clear. It has not yet been determined whether people due to undergo treatment for cancer are able to adhere to dietary restriction interventions. The aim of this thesis was to assess the feasibility of dietary restriction interventions at the time of cancer treatment.
Methods
Three studies were conducted. A systematic scoping review of the literature was performed on dietary restriction at the time of cancer treatment. A Randomised Controlled Trial (RCT), with an embedded qualitative study, was designed to test the feasibility of a 36-hour short-term fast prior to chemotherapy for colorectal cancer. Behavioural change and interview data from a previous RCT of intermittent compared to continuous energy restriction in women receiving chemotherapy for breast cancer was synthesised in a mixed method study.
Results
The systematic review identified that energy restricted diets were tolerated well, however adherence was variable and there was a paucity of qualitative data on patient experiences. Recruitment to the feasibility RCT was delayed due to the COVID-19 pandemic and recruitment is ongoing. Analysis of behavioural change and interview data identified that social influences, dietary preferences, emotional eating, and low self-efficacy act as barriers to adherence.
Conclusion
The findings show limited research on dietary restriction interventions in humans to date. Issues surrounding recruitment and adherence to interventions may affect the feasibility of testing their efficacy. Potential barriers and facilitators of adherence have been identified. Future research should focus on addressing these barriers to improve adherence. Addressing issues with feasibility is required to ensure that the efficacy of dietary restriction can be fully assessed in future studies.

Date of Award	21 Jun 2022
Original language	English
Awarding Institution	University of Bristol
Supervisor	Charlotte Atkinson (Supervisor), Georgia Herbert (Supervisor), Andy Ness (Supervisor) & Claire M Perks (Supervisor)