What is the ketogenic enteral nutrition (KEN) diet?

The ketogenic enteral nutrition (or KEN) diet is an extreme weight loss method where a patient is fed a protein-based solution 24-hours a day, through a tube for ten days. KEN is a short-term treatment for obesity and assists overweight patients with a body mass index (BMI) over 25.

How does KEN work?

KEN works by a doctor inserting a narrow nasogastric feeding tube through the patient’s nose, throat and into their stomach. A drip feeds a protein liquid formula continuously throughout the day and night via a portable pump. The tube can be removed one hour a day to allow for bathing. The continuous infusion of proteins creates a state of ketosis in the body, which takes away all feelings of hunger. After the cycle, there needs to be a ten-day rest period but KEN can be repeated after the interval until the patient reaches their target weight.

Who invented the KEN diet?

The diet was created by Professor Gianfranco Cappello, an associate professor of general surgery at the University of Rome’s La Sapienza Hospital and has now been introduced into the UK.

What are the benefits of the KEN diet?

The diet allows the patient to lose between 4-9% of their initial body weight in a cycle of ten days. The body switches into a ketogenic mode where it breaks down its own fat stored as energy, meaning that patients do not feel hungry and can perform normal daily activities without impairment or the need for additional food. 

What are the drawbacks of the KEN diet?

Nasogastric tubes are normally used to treat sick or chronically ill people. KEN dieters will have to walk around with a tube taped to their nose will have to carry a formula bag, which may be embarrassing. There is no fibre on the KEN diet, which means that laxatives need to be consumed to treat chronic constipation. Another downside of the diet includes foul breath as the ketones released during fat-burning are expelled via the mouth and urine.

What are the side-effects during a ten-day cycle of KEN?

According to Professor Cappello, most patients follow a cycle without presenting any complications that have forced them to discontinue the programme. The disorders most commonly complained about are:

• feeling tired
• heartburn
• nausea or vomiting
• foul breath