Ketogenic versus Mediterranean-style diet during radiotherapy for rectal cancer

Compliance With Ketogenic Diet in Patients Undergoing Radiotherapy for Pelvic Cancers: a Prospective, Randomized, Mono-centric Study

Not applicable Interventional Fondazione Policlinico Universitario Agostino Gemelli IRCCS · NCT05938322

This study will test whether people with locally advanced rectal cancer can follow a ketogenic eating plan compared with a standard Mediterranean-style diet while receiving neoadjuvant chemoradiation.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment194 (estimated)
Ages18 Years to 75 Years
SexAll
SponsorFondazione Policlinico Universitario Agostino Gemelli IRCCS Academic / other
Locations1 site (Rome)
Trial IDNCT05938322 on ClinicalTrials.gov

What this trial studies

Patients with locally advanced, non-metastatic rectal adenocarcinoma scheduled for neoadjuvant radiotherapy are assigned to either an individualized ketogenic diet (carbs <30 g/day, 1.2–1.5 g protein/kg/day, >65% lipids) or a standard diet based on ESPEN/Mediterranean guidelines (45–55% carbs, 15–20% protein, 30–35% lipids). Diet adherence will be measured from patient food diaries, with visits before radiotherapy, once during treatment, and at the end of treatment. Clinical measures including BMI, body composition by bioimpedance, hand-grip strength, and sit-to-stand performance will be recorded, and radiochemotherapy toxicity and compliance will be monitored at routine oncology visits. The primary focus is feasibility and compliance to the dietary plans during the radiochemotherapy period.

Who should consider this trial

Good fit: Ideal candidates are adults with histologically confirmed, locally advanced non-metastatic rectal adenocarcinoma who are scheduled for neoadjuvant radiotherapy and can give informed consent.

Not a fit: Patients who are severely malnourished, have metastatic disease, diabetes, are pregnant or lactating, or have major food allergies that prevent the diets are unlikely to benefit or are excluded.

Why it matters

Potential benefit: If successful, the ketogenic approach could help maintain nutritional status or muscle mass and improve tolerance to chemoradiation for some patients.

How similar studies have performed: Small clinical and preclinical studies have explored ketogenic diets in cancer with mixed and preliminary results, so this approach is promising but not yet well established in radiotherapy for rectal cancer.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Histologic confirmation of rectal adenocarcinoma
* Locally advanced rectal cancer
* Patients undergoing neoadjuvant radiotherapy treatment
* Signature of informed consent to the processing of personal data

Exclusion Criteria:

* Severely malnourished patients according to GLIM (Global Leadership Initiative on Malnutrition) criteria
* Patients treated for palliative purposes
* Patients with metastatic disease
* Diabetes mellitus
* Pregnancy or lactation
* Significant food allergies that would make the person unable to consume the food provided
* Refusal to participate in the proposed clinical trial

Where this trial is running

Rome

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Rectal CancerKetogenic Diet
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.