Efficacy of Time-Restricted Eating (TRE) on Cancer-Related Fatigue, Quality of Life, and Treatment Toxicity in Adult Cancer Patients: A Systematic Review and Meta-Analysis

Cancer-related fatigue (CRF) is one of the most distressing and debilitating symptoms reported by cancer patients undergoing chemotherapy. Time-Restricted Eating (TRE) and other forms of intermittent fasting have been proposed as adjunctive dietary strategies to mitigate CRF, improve quality of life (QoL), and reduce treatment-related toxicity. This systematic review and meta-analysis evaluated the efficacy of TRE on CRF, QoL, and treatment toxicity in adult cancer patients. A systematic literature search was conducted across PubMed, Cochrane Library, Scopus, Web of Science, EMBASE, and CINAHL, covering publications from January 2014 to December 2024. Randomized controlled trials (RCTs) examining the effects of TRE, modified short-term fasting (mSTF), or fasting-mimicking diets (FMD) during active cancer treatment were included. Six RCTs (N=315 participants) met the inclusion criteria. Effect sizes were calculated using standardized mean difference (SMD) for continuous outcomes and odds ratio (OR) for dichotomous outcomes, with a random-effects model. Risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool. Six studies involving adult oncology patients were included. TRE did not significantly improve cancer-related fatigue (MD = 3.17; 95% CI: -0.99 to 7.34; p = 0.13). Quality-of-life outcomes were inconsistently reported across studies. However, TRE significantly reduced severe Grade 3–4 treatment-related toxicities (OR = 0.36; 95% CI: 0.19 to 0.69; p = 0.002), body weight (MD = -1.87 kg; 95% CI: -2.47 to -1.27; p < 0.00001), and fasting blood glucose levels (MD = -4.37 mg/dL; 95% CI: -7.08 to -1.65; p = 0.002). No significant effect on lean body mass was observed (MD = 0.00 kg; 95% CI: -0.19 to 0.20; p = 0.75). Time-Restricted Eating appears to be a safe and feasible nutritional intervention for adult cancer patients undergoing active treatment. TRE may reduce severe treatment-related toxicities and improve metabolic outcomes without compromising lean muscle mass. Although evidence for improving cancer-related fatigue and quality of life remains inconclusive, TRE shows promise as an adjunctive supportive oncology strategy. Larger, high-quality randomized controlled trials are warranted to establish optimal fasting protocols and long-term clinical outcomes.