Common Nutrition Advice That You Should Ignore Vol: 3

27th September 2017, Dietitian Marcus Lee, Mount Miriam Cancer Hospital

‘Ketogenic Diet for Cancer Patients’

Ketogenic diet is a low carbohydrate high fat diet that uses fat to supply 75-90% of energy to your body. It was originally designed to treat epilepsy, however, shouldn’t be attempted without medical supervision, i.e. monitoring of laboratory values to ensure that ketosis is achieved, and dietary consultation and monitoring by a Dietitian who is specialist in ketogenic diet.

In recent years, ketogenic diet is being looked at as part of a treatment plan for cancer patients, for blood sugar control and as a weight-loss programme.

The main drawback of the ketogenic approach is that we don’t yet know whether the diet works in cancer patients. The good news is many clinical trials of the ketogenic diet are ongoing, and we should know within the next few years whether this extreme dietary approach improves outcomes in cancer treatment.


Here are some of the risks of ketogenic diet for cancer patients:

  • Rapid weight loss
  • Nutrient deficiencies (i.e. vitamin D, calcium, magnesium, selenium, and zinc)
  • Electrolyte abnormalities (i.e. sodium, potassium, and chloride)
  • Low blood glucose levels or hypoglycaemia
  • Lack of energy or fatigue
  • Hyperlipidaemia

To conclude, ketogenic diet is not recommended to cancer patients at this point. All patients are encouraged to work with their doctors and dietitians to ensure they’re meeting nutrition needs before, during, and after cancer treatment.


Further reading:

Ketogenic Diet Not Suitable For Cancer Patients. Irish Nutrition and Dietetics Institute, 2015.