TABLE 1.

Characteristics of current studies examining the effect of intermittent fasting during chemotherapy in patients with cancer¹

Author	Sample size and allocation	Type of cancer and treatment	Fasting treatment and trial design	Age, y	BMI	Menopausal status	Adherence
Short-term fasting
Bauersfeld et al., 2018 (40)	n = 34 female block randomization with sealed envelope allocation, allocation nonblinded	breast or ovarian cancers various forms of chemotherapy 6 cycles of chemotherapy	A. STF (36 h before, 24 h after) then normocaloric (n = 18)B. Normocaloric then ST (n = 16)randomized crossover trial	A. 49.8B. 53.6	A. <25: 925 to <30: 7≥30: 2B. <25: 1025 to <30: 6≥30: 0	A. Pre: 72.2% Post: 27.8%B. Pre: 68.7%Post: 31.3%	102 cycles fasted 74 cycles normocaloric 5 patients didn't want to switch to normocaloric after first arm
de Groot et al., 2015 (41)	n = 13 femalerandomized	HER2-negative stage II/III breast cancer receiving neoadjuvant TAC (docetaxel/doxorubicin/cyclophosphamide)dexamethasone use	A. STF (24 h before and after) (n = 7)B. Control (n = 6)randomized control trial	A. 51B. 52	A. 25.5B. 23.8	—	2 participants dropped out in the STF group due to neutropenia and pyrosis, did not resolve with normal diet
Dorff et al., 2016 (29)	n = 20 male and female	cancer diagnosis prescribed platinum-based chemotherapy without radiation, curative or palliative dexamethasone use and 5HT3 inhibitors	A. 24 h STF (n = 6)B. 48 h STF (n = 7)C. 72 h STF (48 h before/24 h after) (n = 7)nonrandomized, feasibility trial, no control	61	≥20.5		A. 4/6 compliantB. 5/6 compliantC. 4/7 compliant
Riedinger et al., 2020 (30)	n = 20 femalenonblinded randomized	Gynecologic cancers with ≥6 cycles of chemotherapyMultiagent chemotherapy (bevacizumab, carboplatin, cisplatin, docetaxel, doxorubicin, gemcitabine, and paclitaxel), ≥2 participants neoadjuvant therapy	A. STF (24 h before and after) (n = 10)B. Control (n = 10) – balanced, normocaloric dietRandomized control trial	A. 59.5B. 59.0	A. 27.69B. 29.06		9% dropout rate in the fasting group. No compliance data given. Serum glucose tested to indicate adherence
Safdie et al., 2009 (23)	n = 10 male and female	Neoplasia of breast, esophagus, prostate, lung, uterus, ovary	Voluntarily fasted (48–140 h prior to and 5–56 h following treatment) during treatmentCase series report	61	—	—	—
Zorn et al., 2020 (36)	n = 30 femaleselectively assigned (nonrandomized)	Breast, endometrial, ovarian, or cervical cancer, first diagnosis/recurrence all stages, neo or adjuvant chemotherapy, ≥4 cycles	A. mSTF/NC (n = 7)B. NC/mSTF (n = 9)C. KD + mSTF/NC (n = 1)D. NC/KD + mSTF (n = 13)Crossover2–3 cycles of CTX of intervention and control	54	26	—	41% dropout rate71.4% of fasting participants had physiological blood ketosis detected“difficult”: 1 “quite difficult”: 11 “quite easy” or “easy”: 9
Fasting mimicking diet
de Groot et al., 2020 (22)	n = 129 femaleblock randomization	HER-2 negative stage II/III breast cancer, neoadjuvant FEC-T or AC-T chemotherapy. Dexamethasone dc in FMD group	A. FMD (n = 65)B. Control (n = 64)Diet was 3 d prior to and the day of treatment. Randomized control trial, observer blind	49	25.7	Pre/peri: 41.5%Post: 58.5%	All cycles: 21.5%4 cycles: 33.8%2 cycles: 50%First cycle: 81.5%Used ITT/per-protocol analysis
Lugtenberg et al., 2020 (37)	n = 129 femaleblock randomization	HER-2 negative stage II/III breast cancer, neoadjuvant FEC-T or AC-T chemotherapy	A. FMD (n = 65)B. Control (n = 64) Randomized control trial, observer blindDiet was 3 d prior to and the day of treatment	49	25.7	Pre/peri: 58.5%Post: 41.5%	All cycles and surgery: 15.4%All cycles: 21.5%Half of cycles: 33.8%First cycle: 81.5%

¹AC-T, Adriamycin Cyclophosphamine Taxol regimen; CTX, Cyclophosphamide; FEC-T, Fluorouracil-Epirubicin-Cyclophosphamide-Docetaxel; FMD, fasting mimicking diet; ITT, intention to treat; KD + STF, ketogenic diet combined with short-term fasting (KD 6 d prior to STF); mSTF, modified short-term fasting (<25% of energy needs); NC, normocaloric diet; STF, short-term fasting; TAC, Taxotere-Adriamycin-Cytoxan regimen