Fasting-Based Dietary Interventions in Cancer Patients and Survivors: A Scoping Review

Area of Science:

• Oncology
• Nutritional Science
• Integrative Medicine

Background:

• Fasting-based interventions are explored as complementary cancer treatments.
• Potential benefits include reduced treatment toxicity, improved metabolic health, and enhanced quality of life.
• Current clinical evidence is limited and fragmented.

Purpose of the Study:

• To systematically map existing evidence on fasting interventions in cancer patients and survivors.
• To categorize fasting types and assess outcomes like fatigue, toxicity, and metabolic parameters.
• To evaluate adherence, acceptability, and adverse events associated with fasting.

Main Methods:

• Scoping review of interventional studies from major databases up to June 2025.
• Included studies evaluated fasting-mimicking diets (FMD), time-restricted eating (TRE), short-term fasting (STF), or intermittent fasting (IF).
• Outcomes assessed included fatigue, treatment toxicity, metabolic/hematologic parameters, quality of life, adherence, and adverse events.

Main Results:

• Twenty studies (871 participants) evaluated various fasting methods, primarily in breast cancer patients undergoing chemotherapy.
• Evidence suggests reductions in fatigue (5/6 studies) and chemotherapy toxicity (6/8 studies).
• Metabolic benefits include weight loss (10/12 studies) and reduced IGF-1/insulin levels; adherence and acceptability were generally high, though outcomes varied by fasting type.

Conclusions:

• Fasting interventions appear feasible and well-tolerated in cancer patients and survivors.
• Early evidence indicates potential benefits in reducing fatigue, treatment toxicities, and improving metabolic health.
• Larger, diverse trials are essential to confirm long-term outcomes and inform clinical integration.