Ketogenic diet

The ketogenic diet is a high fat, low carbohydrate, controlled protein diet.

Usually the body uses glucose from carbohydrates (found in foods like sugar, bread or pasta) for its energy. When following a ketogenic diet the body uses ketones instead of glucose for its energy.

Chemicals called ketones are made when the body uses fat for energy (this is called ‘ketosis’). The ketones are used as an energy source throughout the body, especially for the brain. It’s not completely understood how the ketogenic diet works, but there is some evidence that the brain needs energy from glucose (a sugar) to create a seizure.

There are 2 modified ketogenic diets which are sometime used for epilepsy. They are the Modified Atkins Diet (MAD) and the low glycaemic index treatment (LGIT) diet. These diets are less strict and can be easier to manage.

• The ketogenic diet is considered when someone has tried 2 or more epilepsy medicines and has still not got seizure control
• To mainain a state of ketosis it is important to stick to the ketogenic diet closely. Chemicals called ketones are made when the body uses fat for energy (this is called ‘ketosis’)
• The first few weeks are generally the most challenging. You will be learning to cope with significant changes in meal planning, shopping for new foods, measuring food portions and adapting your cooking
• The diet should always be done with the support and supervision of a dietitian
• At the moment only a very small number of NHS hospitals offer a ketogenic diet service for adults. If you are on the diet as a child and then transition to adult services it may not be easy to have the same support and supervision

Studies have shown that about half of children will have a good response to the ketogenic diet and some will become seizure free.

There isn’t as much evidence for how effective the ketogenic diet is for adults, but some people do find it reduces their seizures.

When starting the diet it’s normal to feel lethargic, weak or even dizzy and nauseous while the body adapts and switches to burning fat as its fuel.  Some may experience episodes of low blood glucose or high ketones and occasionally vomiting or an increase in seizures.

Other side-effects include weight loss, constipation or diarrhoea, high cholesterol and kidney stones. Some of these side-effects can be serious, so it’s important to have careful monitoring while on the diet.