Effect of Nutrition Education Focusing on Dietary Quality on Cancer-Related Fatigue in Breast Cancer Patients: A 12-Week Randomized Controlled Trial

<b>Background</b>: Cancer-related fatigue (CRF) is a prevalent, persistent, and multidimensional symptom in breast cancer patients, negatively affecting physical function and quality of life (QoL). Dietary interventions have emerged as safe and cost-effective strategies to alleviate CRF. <b>Methods</b>: This assessor-blinded, randomized controlled trial evaluated the effects of a 12-week dietary quality-based nutrition education program on CRF in breast cancer patients. A total of 128 participants were randomly assigned to the intervention, which received nutrition education based on the Chinese Healthy Eating Index (CHEI), or the control group, which received standard care. Outcomes, including CRF (Revised Piper Fatigue Scale), dietary quality (CHEI), body mass index (BMI), self-management efficacy (Strategies Used by People to Promote Health, SUPPH) and QoL (Functional Assessment of Cancer Therapy-Breast, FACT-B) were assessed at baseline and post-intervention. <b>Results</b>: Of the 128 participants, 111 (86.7%) completed follow-up. Linear mixed-effects models demonstrated a significant group × time interaction for total RPFS scores. After adjusting for age, BMI, cancer stage, pain, anxiety, and depression, the intervention group showed a significantly larger reduction in RPFS scores (β = -1.426, 95% CI: -1.959~-0.893, <i>p</i> < 0.001, Cohen's d = -0.97). In addition, after adjusting for the same covariates, significant improvements were observed in CHEI (β = 4.799, 95% CI: 1.383~8.215, <i>p</i> = 0.006, Cohen's d = 0.75), SUPPH scores (β = 16.657, 95% CI: 12.557~20.758, <i>p</i> < 0.001, Cohen's d = 1.65) and FACT-B scores (β = 12.688, 95% CI: 9.250~16.125, <i>p</i> < 0.001, Cohen's d = 1.16) in the intervention group, all showing meaningful changes compared with the control group. <b>Conclusions</b>: Dietary quality-based nutrition education significantly alleviated CRF and improved other health-related outcomes in breast cancer patients, suggesting that nutrition education may be an effective strategy for managing CRF and supporting recovery during breast cancer treatment.