Japan Tests Low-Carb Tube Feeding After Cancer Surgery

Japanese Surgeons Ask: Does Low-Carb Tube Feeding Protect Non-Diabetic Cancer Patients Too?

A study from Japan published in PLOS One (2025) is investigating whether low-carbohydrate tube feeding (enteral nutrition) can reduce dangerous blood sugar spikes in non-diabetic patients recovering from esophageal cancer surgery. The trial is being conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research in Tokyo — one of Japan's leading oncology centers.

Why This Research Stands Apart

Most existing research on post-surgical blood sugar management focuses on patients who already have diabetes. This Japanese trial takes a different approach, asking whether people without a diabetes diagnosis are also at risk from surgery-related blood sugar surges — and whether their diet during recovery should be adjusted accordingly. This question has received relatively little attention in US clinical research, making the international perspective particularly valuable.

Esophagectomy (surgical removal of part of the esophagus) is a major, hours-long operation. Japanese surgical teams have already established that diabetic patients do better on low-carbohydrate tube feeding after this procedure. Now researchers want to know if the same benefit applies to everyone undergoing the surgery.

How the Study Works

Fifty patients will be randomly divided into two groups: one receiving standard tube feeding and one receiving a low-carbohydrate tube feeding formula. Neither group has a prior diabetes diagnosis, though some participants have HbA1c levels in the prediabetes range (6.0–6.4%).

Researchers will use continuous glucose monitors (CGMs) — the same wearable sensor technology increasingly familiar to US patients — to track blood sugar around the clock for eight days after surgery. The primary goal is to measure Time-in-Range (TIR), defined as the percentage of time blood sugar stays within 70–180 mg/dL. This is the same TIR target recognized by the American Diabetes Association.

Key Measurements Being Tracked

• Time-in-Range (TIR): How long blood sugar stays between 70–180 mg/dL
• Time-Above-Range (TAR): How often blood sugar exceeds 180 mg/dL
• Post-surgical infections within 30 days
• Nutritional markers such as albumin and prealbumin levels

What US Guidelines Currently Say

Current US guidelines from the American Diabetes Association and the Society of Critical Care Medicine emphasize tight glucose control in hospitalized diabetic patients, targeting blood sugar between 140–180 mg/dL in most ICU settings. However, formal guidance for non-diabetic surgical patients remains limited — which is precisely the gap this Japanese trial aims to address. If the findings support glycemic management in non-diabetics, it could prompt updates to perioperative care protocols worldwide, including in the US.

Why This Matters for US Patients

For Americans facing major surgery — especially cancer surgery — blood sugar control during recovery may be important even without a diabetes diagnosis. Surgical stress, anesthesia, and post-operative inactivity can all cause temporary blood sugar spikes that increase infection risk and slow healing. This study could provide evidence to support more proactive nutritional planning for all surgical patients, not just those with diabetes.

Understanding your everyday blood sugar patterns before any major medical event is also valuable. Tools available at mdsdiabetes.com — including CGM supplies and blood glucose monitors — can help you and your care team establish your personal baseline and stay informed about how your body responds to metabolic stress.

Full Citation

Terayama, Imamura, Kitazawa (2025). Study protocol: The effect of a low-carbohydrate enteral nutrition formula on postoperative hyperglycemia in non-diabetic patients with esophageal cancer: A randomized exploratory phase II trial (ENLICHE study). PLOS One. PMID: 40435183. DOI: 10.1371/journal.pone.0325039. [Country of Origin: Japan]