What is a Very Low Calorie Ketogenic Diet (VLCKD)?

On a VLCKD, you consume 6 meal bags (shakes) per day. These sachets are extremely low in fats and carbohydrates and very high in protein. Due to the very low intake of carbs and fats, your body starts using its own energy reserves. After 48 hours, this primarily means burning fat stores (through ketosis). Thanks to the high protein content, lean body mass is preserved as much as possible1,2,3,4,5,6,7,8.

The effect of a pre-operative diet​

• Reduced liver volume2,3,4. 
• Reduced liver fat (NASH)1,2,3,4. 
• Reduced visceral fat1. 
• Lower perceived difficulty of the procedure. 
• Fewer complications during the procedure5,7,8. 
• Reduced operation time1,5,7,8. 
• Fewer post-operative complications (meaning shorter hospital stays)1,5,7,8. 
• More weight loos after surgery5,7,8.

Possible complications of bariatric surgery

The most common procedures are the gastric bypass (RYGB) and the sleeve gastrectomy. These are usually performed laparoscopically, but in patients with morbid obesity, this presents additional challenges. An enlarged liver and increased fat content can complicate the surgery, limit visibility, and increase the risk of bleeding and other complications1,2,3,4. This can lead to longer operation times, extended hospital stays, and both intra- and post-operative complications, such as increased bleeding1,3,4.

Preventing complications

A pre-operative Very Low Calorie Ketogenic Diet (VLCKD) aims to reduce body weight, abdominal fat, and liver volume, significantly lowering the risk of complications.

Guidance is essential

A VLCKD should always be followed under the supervision of a physician or certified dietitian. A medical screening (including blood tests) is recommended before starting the diet, along with regular follow-up throughout its implementation.

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