Keto Diet During Radiotherapy: KOMPARC Trial Preliminary Results
Preliminary results from the KOMPARC trial, published on 19 January 2026 in the journal Nutrients, show that a ketogenic diet is clinically tolerable and safe for patients with cervical and endometrial cancer undergoing radiotherapy. The prospective randomised open-label trial at the Policlinico Universitario Agostino Gemelli IRCCS in Rome enrolled 33 patients (48.5 percent cervical, 51.5 percent endometrial) and compared keto with a standard Mediterranean diet as a complementary nutritional strategy during pelvic radiotherapy. No serious Grade 3+ diet-related complications were reported in the initial analysis window. The trial is still recruiting, with primary completion expected by December 2026.
Why researchers are testing keto during radiotherapy
Radiotherapy is a cornerstone of treatment for cervical and endometrial cancers, but it is associated with significant metabolic stress and changes to body composition. Researchers hypothesise that a ketogenic diet, by reducing circulating glucose and promoting ketone production, could enhance the metabolic selectivity of radiotherapy: creating conditions less favourable for tumour cells while supporting normal tissue. The KOMPARC study was designed to evaluate whether this nutritional approach is safe and whether patients can adhere to it throughout a demanding treatment course.
How the KOMPARC trial was designed
KOMPARC is a prospective, randomised, open-label controlled trial. Of the 33 patients enrolled, 48.5% had cervical cancer and 51.5% had endometrial cancer; all were scheduled to receive pelvic radiotherapy. They were randomised to either a ketogenic diet or a standard Mediterranean diet for the duration of their radiotherapy course. The primary outcomes in the preliminary analysis were safety and clinical tolerability, assessed through monitoring for adverse events, nutritional status, and treatment completion rates. The trial is still recruiting, with a primary completion date estimated for December 2026.
What the January 2026 preliminary results showed
The preliminary results, published in the MDPI journal Nutrients, confirmed that a ketogenic diet can be safely implemented in this patient population without significantly increasing adverse events compared to the Mediterranean diet group. No serious (Grade 3+) diet-related complications were reported during the initial analysis period. Gastrointestinal toxicities occurred in 60.7% of participants overall (70% in the ketogenic group vs. 55.6% in the Mediterranean group; p=0.56), with no statistically significant difference between groups. Adherence was a key challenge: 46.1% of participants in the ketogenic diet group interrupted the diet at some point, compared with 25.0% in the standard Mediterranean diet group (p=0.21). Patients undergoing radiotherapy often experience fatigue, nausea, and appetite changes that make strict dietary adherence difficult. The research team at the Clinical Nutrition Unit provided intensive dietitian support to participants, which the authors identified as a critical component of the protocol's feasibility.
Body composition and nutritional concerns in cancer patients
One of the central concerns about using a ketogenic diet in cancer treatment is the risk of worsening cachexia, the progressive loss of muscle and body weight that affects many cancer patients. The KOMPARC preliminary data did not show a significant increase in muscle loss in the keto group compared to the Mediterranean group, but the authors cautioned that longer follow-up is needed. Adequate protein intake is critical on keto for cancer patients, and the protocol was designed with a protein-adequate ketogenic formulation rather than a classic fat-heavy clinical keto diet, to better preserve lean mass.
What clinicians and patients should take from this
The KOMPARC preliminary data are encouraging but preliminary. They support the conclusion that a keto diet can be trialled safely alongside radiotherapy in selected patients with appropriate nutritional support. They do not establish that keto improves cancer outcomes compared to standard care. Full efficacy data on tumour response and quality-of-life outcomes will not be available until the trial completes in late 2026 or early 2027. Patients with gynaecological cancers who are considering dietary modifications should discuss them with their oncology team before making any changes. Unsupervised dietary restriction during cancer treatment is not recommended.
FAQ
Is it safe to do keto during radiotherapy?
Preliminary data from the 2026 KOMPARC trial suggest that a ketogenic diet can be safely implemented alongside pelvic radiotherapy in patients with cervical or endometrial cancer when supervised by a trained dietitian and medical team. However, this should not be attempted without medical supervision, as nutritional demands during cancer treatment are complex.
What is the KOMPARC trial?
KOMPARC is a prospective randomised controlled trial testing a ketogenic diet versus a standard Mediterranean diet in women with cervical and endometrial cancer undergoing radiotherapy. It is being conducted at the Policlinico Universitario Agostino Gemelli IRCCS in Italy. Preliminary results were published in January 2026, with full completion expected in late 2026 to 2027.
Does keto help with cancer treatment?
The evidence is promising but preliminary. Several clinical trials are investigating whether keto can improve outcomes in various cancers, including glioblastoma and gynaecological malignancies. Safety data are encouraging. However, keto is not currently an evidence-based standard-of-care intervention for any cancer type, and no trial has yet demonstrated a statistically significant survival benefit in a Phase III study.