Ketogenic Diet
- What is the ketogenic diet?
- Who is the diet for?
- What is involved prior to commencing the ketogenic diet?
- What happens during the admission for the ketogenic diet?
- Does it work?
- What does it look like?
- What is required at home?
- What problems can arise?
- Commonly asked questions?
- Links
- References
What is the ketogenic diet?
The Ketogenic diet is a strict, medically supervised diet that may be a treatment option for some children with epilepsy. It involves a high fat and very low carbohydrate and protein diet that ensures the body will burn fat rather than carbohydrate and protein for energy, thus producing ketones. In some ways, the diet mimics the body’s metabolic state during fasting or illness. This high ketone state (ketosis) decreases seizure activity in some circumstances by mechanisms which are not fully understood. The diet deliberately maintains this build up of ketones by a strictly calculated, individual regimen with rigid meal plans.
The ketogenic diet is not a "natural therapy". Less is known about the beneficial and adverse effects of the ketogenic diet than other treatments for epilepsy eg. antiepileptic medications and surgery. The ketogenic diet has not been subjected to the usual clinical trials that establish efficacy and safety of a treatment for a medical condition.
Who is the diet for?
The ketogenic diet is generally only suitable for children with poorly controlled seizures. Assessment by a paediatric neurologist experienced in epilepsy management and monitoring of the diet and drug therapy is a prerequisite. Generally, young children with mixed myoclonic seizure disorders and uncontrolled absence seizures are thought to respond best to the ketogenic diet. Some centres have reported success with adult patients and patients with other epilepsies.
In our Program, only children with severe epilepsy which has not responded to medication, and who are not suitable for surgery, are usually considered for the ketogenic diet. Our Program allows for only one child per month to be admitted for the ketogenic diet, due to limited resources.
What is involved prior to commencing the ketogenic diet?
- Initial assessment
All children and families require a referral from their neurologist or paediatrician to the Ketogenic Diet Clinic for assessment of suitability. At this visit families will be seen by a paediatric neurologist, dietitian and epilepsy nurse specialist experienced in the implementation and monitoring of the ketogenic diet. If the child is felt to be suitable and the family wish to proceed they will attend a second education session.
- Education
Families must be fully informed about the ketogenic diet before embarking on this form of treatment. Information is given in the form of written material and formal "one on one" discussions. Areas covered include broad aims of the diet, how the diet works, advantages and disadvantages, the classic diet and how it is calculated, examples of meals, duration of diet, admission process and ongoing management at home. If a joint decision by the Ketogenic Diet Team and family is made to proceed with the ketogenic diet, a hospital admission is scheduled.
- Seizures
Frequency and type of seizures must be documented for one month prior to commencing the ketogenic diet and throughout the course of the diet. The neurologist may wish to review medications before the diet is commenced, particularly as syrup medications have a high sugar content.
What happens during the admission for the ketogenic diet?
All children who are to commence the diet are admitted to hospital for a 4-5 day stay. Usually, admission is from Monday to Thursday, the child being discharged on Thursday if all goes well. Admission is initially to the Neuroscience Unit (8th floor) and then families move to the Care by Parent Unit.
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Neuroscience Unit (8th Floor) |
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- Nutrition
The aim is to induce ketosis. Children will be given a ketogenic formula to drink (Ketocal). The child may drink water through out this time. If the child does not drink enough they may require a soft plastic tube to be inserted through the nose into the stomach to maintain fluid intake. If ketosis is being established and the ketogenic diet tolerated food may be introduced after a 48-hour period until the calculated ratio and energy level is reached. The dietitian calculates all energy requirements and grades the fat ratio up slowly.
- Tests
Baseline blood, urine and radiological investigations are performed on admission. Blood sugar levels are monitored to ensure that they do not become too low. To do this, finger prick blood tests are performed every 6 hours and may be required more frequently if sugar levels are too low. Low blood sugars are treated with a high sugar drink. Blood ketones levels are also monitored 6 hourly and urine ketone levels are tested at least twice daily. Special dipsticks indicate ketone levels and this form of monitoring will continue at home. Everyday the child is weighed to monitor weight losses or gains.
- Medications
All medications continue as normal, unless changed by the neurologist. Medications will be given in tablet or capsule form.
- Activity
All children are encouraged to maintain normal levels of activity and are not confined to bed. Play therapists become involved with families during the admission. Seizures are monitored by parents and staff.
- Parental Involvement
Parents are encouraged to participate in all aspects of care throughout the hospital stay as this is considered part of the education process. If the child and family are managing well by day 3, they move from the Neuroscience Ward to the Care by Parent Unit located within the hospital. Contact with the Ketogenic Diet Team is still maintained through this time until discharge on day 4-5. Regular education sessions occur with the dietitian and epilepsy nurse coordinator to ensure families will be able to manage at home.
- What happens after discharge home?
Fine tuning of the diet, especially for the first few weeks at home, is often required. Close contact with the dietitian, epilepsy nurse and neurologist if necessary, is maintained throughout this time. Appointments will be made for formal outpatient review after one, two, three and six months, but more frequently if required. Routine blood tests will continue to be taken at regular intervals by local pathology services or Royal Children’s Hospital pathology services. Twice daily ketone urine monitoring and regular weights need to be recorded.
- Trial Period
A trial period of at least 10-12 weeks is needed to assess whether the ketogenic diet is having beneficial effects on the child’s seizures. Antiepileptic medications should continue unchanged through this period, unless otherwise advised by the neurologist. If there is a significant reduction in seizures, the diet is maintained for approximately 18 months to 2 years. Medications may be reduced or withdrawn during this period. If after the trial period there is no significant improvement, the diet is not tolerated, or the diet is judged too difficult to manage, a joint decision between families and the ketogenic diet team will be made to determine whether the diet should be ceased.
Does it work?
The ketogenic diet does not control seizures in all children. In fact, only a relatively small proportion of children benefit significantly from the ketogenic diet. A recent review of our experience with the ketogenic diet in 30 children revealed:
- 36% of children had a significant improvement with more than 50% reduction in seizures
(16% became seizure free); - 28% of children had a small improvement with less than 50% reduction in seizures;
- 36% of children had no response.
This roughly equates to 1 in 3 children having a significant reduction in seizures, 1 in 3 having only a slight improvement in seizures, and 1 in 3 having no improvement in seizures.
Some centres around the world report up to 50% of their patients having a significant improvement with the diet, however, it should be noted that patient selection and reporting differ between centres.
What does it look like?
Food is usually divided into three or four meals per day and allows for the child to receive enough energy requirements for normal growth. Meals tend to be small and very oily and water is the main fluid allowed, the volume being restricted to 120-150mls over each 1 hour period. As the diet is nutritionally inadequate daily vitamin and mineral supplements are necessaary.
Below is a range of meals suitable for children of different ages.
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Egg nog drink Egg and cheese salad Puree zuchini and chicken Fruit selection Chicken stir fry Egg omlette Egg and bacon quiche |
Below is a day menu and breakdown of ingredients for a 7 year old child.
| Breakfast: | Scrambled egg and apple sauce meal | |
| 45 grams | whole raw egg | |
| 15 grams | butter | |
| 3 grams | nuts | |
| 30 grams | raw granny smith apple | |
| 13 grams | fresh olive oil | |
| 10 grams | regular butter | |
| 5 grams | thickened Farmers’ Union cream | |
| Lunch: | Creamy bacon meal | |
| 20 grams | raw green capsicum |  |
| 20 grams | raw celery | |
| 20grams | raw brown onion | |
| 64 grams | 35% ideal dairy cream | |
| 27 grams | lean middle bacon | |
| 22 grams | Sundew margarine | |
| Dinner: | Chicken and vegetable stir-fry | |
| 30 grams | peeled raw carrot |  |
| 30 grams | raw green capsicum | |
| 30 grams | raw broccoli | |
| 14 grams | raw brown onion | |
| 23 grams | lean raw chicken breast | |
| 42 grams | olive oil | |
| 5 grams | commercial soy sauce | |
What is required at home?
Basic equipment for home includes:
- a calculator
- electronic weigh scales accurate to 1 gram
- measuring cup
- vitamin supplements
- urine testing strips (ketodiastix)
- computer access with excel program
The ketogenic diet must be strictly followed at all times. Children attending play group, kindergarten, school or social occasions must take the required meal with them and all carers and teachers must be fully informed of the diet. Families initially find planning and preparing the diet very time consuming, but with practice this becomes easier and faster. Shopping practices change, but costs are comparable to normal household budgets. The initial outlay for necessary equipment may be a cost factor.
What problems can arise?
- Loss of ketosis occasionally presents as a problem in some children on the ketogenic diet and may occur because of several factors. These include:
- the child is given food that is not on the ketogenic diet or is secretly eating extra food
- incorrect calculation and preparation of food
- the child is unwell
- incorrect nutritional content documented on food product labels
- Constipation can occur because of the small volume of food and fibre consumed.
- Weight loss or gain.
- Height slowing
- Inappropriate food related behaviours such as refusal of certain foods, carrying packets of food around.
- Compliance of children may be an issue especially in some social circumstances.
- Less common and potentially more serious long term side effects include:
- Renal stones have been described in 5-8% of children.
- Susceptibility to infections
- Thinning of the bones
- Routine blood tests have been reported as showing low protein, anaemia and high cholesterol, but the significance of this, especially in relation to cardio/vascular disease, is unknown.
Commonly asked questions?
The following link to the Packard Children’s Hospital Stanford University Medical Centre, USA web site offers a comprehensive guide to commonly asked questions.
http://www.stanford.edu/group/ketodiet/
We recommend that any questions specific to your child or treatment at our centre be discussed directly with your Neurologist or the Epilepsy Nurse Specialist at the Children’s Epilepsy Program.
Links
The following sites may be useful for further general information regarding the ketogenic diet.
- The Epilepsy Foundation of Victoria. This site has other informative links, access to ordering books, often relevant articles and a good general epilepsy site.
http://www.epinet.org.au
- Packard Children’s Hospital Stanford University Medical Centre
http://www.stanford.edu/group/ketodiet/
- Johns Hopkins Epilepsy Centre
www.neuro.jhmi.edu/Epilepsy/keto.html
References
- Freeman JM et al. The efficacy of the ketogenic diet-1998: a prospective evaluation of intervention in 150 children. Pediatrics. 102(6): 1358-63,1998 Dec. [PubMed]
- Hemingway C et al. The Ketogenic Diet: A 3- to 6- year follow-up of a 150 children enrolled prospectively. Pediatrics 108(4):898-905, 2001 Oct. [PubMed]
- Vining EP et al. A multicenter study of the efficacy of the ketogenic diet. Archives of Neurology. 55(11):1433-7, 1998 Nov. [PubMed]
- Kinsman SL et al. Efficacy of the Ketogenic Diet for intractable seizure disorders: review of 58 cases. Epilepsia 33(6):1132-1136, 1992 [PubMed]
- Sirven J et al. The ketogenic diet for intractable epilepsy in adults: preliminary results. Epilepsia. 40(12):1721-6, 1999 Dec. [PubMed]
- Ballaban-Gil K et al. Complications of the ketogenic diet. Epilepsia. 39(7):744-8, 1998 Jul. [PubMed]
- Lefevre F, Aronson N. Ketogenic Diet for the Treatment of Refractory Epilepsy in Children: A Systematic Review of Efficacy. Paediatrics. 2000 Apr;105(4):E46 [PubMed]
- The Epilepsy Diet Treatment: An introduction to the Ketogenic Diet (2nd Ed.) by John Freeman, 1996. IBSN No.1-888799-39-0. This book can be purchased or borrowed from the Epilepsy Foundation of Victoria library.