The feasibility and safety of fasting-mimicking diet in breast cancer patients with chemotherapy in China.
Level 4 - case-series / case-control
Single-arm, uncontrolled pilot clinical trial
PubMed 40711668 · doi:10.1007/s10549-025-07756-w
What was done
A single-arm pilot clinical trial in China evaluated the feasibility, safety, and metabolic effects of a recipe-based fasting-mimicking diet (FMD) in 30 breast cancer patients undergoing chemotherapy. Participants consumed an FMD providing 34% to 54% of normal caloric intake for 4 days before and on the day of chemotherapy across 3 treatment cycles. Adverse events, body composition, and serum biomarkers were evaluated.
What was found
Of 30 enrolled patients, 27 completed all 3 FMD cycles. Grade III or worse FMD-related adverse effects occurred in 5.95% of cycles (5/84). Serum IGF-1 significantly decreased from baseline after the first cycle (B = -23.29, p = 0.001) and second cycle (B = -16.20, p = 0.023), but not after the third cycle (B = -8.372, p = 0.327). Following 3 cycles and a 21-day washout, patients had significant reductions in total body mass (-2.04 kg, 95% CI -2.86 to -1.21 kg, p < 0.001), fat mass (-1.88 kg, 95% CI -2.72 to -1.05 kg, p < 0.001), visceral fat area (-14.78%, 95% CI -21.13% to -8.43%, p < 0.001), and waist circumference (-4.01, 95% CI -6.18 to -1.83, p < 0.001), whereas muscle mass did not change significantly (-0.05 kg, 95% CI -0.36 to 0.27 kg, p = 0.270).
Why it matters
This study demonstrates that a recipe-based fasting-mimicking diet is feasible during breast cancer chemotherapy in a Chinese cohort, achieving body fat reduction without muscle loss.
Limits
The study is limited by a small sample size (n = 30) and an uncontrolled, single-arm design. Long-term oncologic efficacy, chemotherapy toxicity differences versus standard diet, and clinical outcomes were not assessed.