Intermittent fasting appears feasible and safe as an adjunct to chemotherapy in normal-weight patients with cancer, but there is insufficient evidence to support this diet as a way to improve disease or treatment outcomes, a review suggests. These findings were reported in a poster presentation at JADPRO Live 2022, the annual APSHO meeting.

The poster authors explained that intermittent fasting involves following a pattern of calorie restriction or calorie reduction over set periods of time, and the diet’s popularity among patients with cancer has increased. However, research on the feasibility, safety, tolerability, and treatment effect of intermittent fasting during chemotherapy is limited.

The authors conducted a comprehensive literature search to evaluate the evidence on intermittent fasting in patients with cancer undergoing systemic therapy and to identify the limitations in the evidence-based information to guide clinical decision making.

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The final analysis included 7 studies — 3 randomized controlled trials, 2 crossover trials, and 2 cohort studies.

The authors examined 4 outcomes to understand how intermittent fasting affects patients with cancer and cancer treatment: fasting compliance, malnutrition, therapy side effects, and cancer outcomes.

The results showed overall good compliance, no malnutrition, and minimal side effects.

There were mixed results for cancer outcomes, however. Two studies showed increased treatment response with intermittent fasting, but 1 study showed no difference in treatment response.

Limitations of the studies include small sample sizes; bias toward gender, race, and cancer type; interventions involving only normal-weight patients (BMI >18 kg/m2); variation in fasting protocols; and short-term follow-up surveillance.

Given these limitations, the findings are less generalizable to the greater oncology patient population, the authors wrote. Large-scale randomized controlled trials are needed to validate these findings and determine what future role intermittent fasting may play in cancer management.

The authors recommend that advanced practitioners ask cancer patients about their diets, as patients may make changes without medical guidance. Advanced practitioners should also use caution when considering intermittent fasting as an adjunct to chemotherapy.

Disclosures: The study authors did not disclose any conflicts of interest.


Thompson S, Bazzell AF. Intermittent fasting during systemic therapy: Evidence for the oncology advanced practitioner. Poster presented at: JADPRO Live 2022; October 20-23, 2022; Aurora, CO. Abstract JL1020C.

This article originally appeared on Oncology Nurse Advisor