Abstract
A diagnosis of colorectal cancer and its subsequent treatments can have a significant impact on dietary decisions, but what these drivers are in the New Zealand population and what information underpins these decisions requires further investigation. This research aimed to explore whether patients made dietary changes after a diagnosis of colorectal cancer, and what factors influenced these changes. In addition, what dietary information has been provided along the treatment pathway and does this meet the needs of this patient population? A qualitative study method was used to explore the lived experiences of individuals undergoing treatment for colorectal cancer at Christchurch Hospital. Patients were recruited at the Computed Tomography (CT) radiotherapy planning appointment, and semi-structured interviews were conducted in week two or three of their chemoradiotherapy treatment. The interview questions focused on how diet is impacted by diagnosis, treatment side effects, access to information, and personal beliefs. Over five months, 14 patients were recruited, receiving concurrent chemoradiotherapy for Stage 3 & 4 Rectal Cancer. Audio-recorded interviews were transcribed verbatim, coded and analysed using reflexive thematic analysis(1). Participants described varying degrees of dietary change, with treatment side-effects, particularly nausea, fatigue, taste changes, and bowel changes emerging as key drivers of food choice. Many adopted a flexible, reactive approach to eating, often prioritising what was manageable over what was considered nutritionally optimal. Changes included reduced appetite, aversions to certain foods, decreased portion sizes, and a preference for bland or easy-to-prepare meals. Some participants experienced distress or uncertainty navigating treatment-imposed dietary routines (e.g., low-fibre diets or eating with medication), often without adequate support or explanation. Dietary changes were also influenced by personal beliefs (e.g., avoiding sugar, alcohol or processed meats perceived as harmful), and input from family, friends, or online sources. The emotional significance of food, including feelings of guilt around eating, further shaped dietary decisions. Logistical challenges, such as being away from home for treatment and limited access to cooking facilities also influenced participants’ ability to maintain usual eating patterns. Participants reported inconsistent access to dietary guidance, with some receiving timely, helpful input while others felt information was lacking. The findings suggest a need for more personalised colorectal cancer-specific dietary advice and improved integration of nutrition into the cancer care pathway to better support patients' evolving needs.