|Year : 2014 | Volume
| Issue : 2 | Page : 76-78
Eponyms in medical nutrition and nutraceuticals: The Ketogenic diet for seizure control
Sandra D Scrivens
Alton, Hampshire, United Kingdom
|Date of Web Publication||6-May-2014|
Sandra D Scrivens
Registered Dietitian, Alton, Hampshire, United Kingdom
Source of Support: None, Conflict of Interest: None
This review forms part of a series on Eponyms in Medical Nutrition and Nutraceuticals. The Ketogenic Diet (KD), a therapeutic diet for seizure control in intractable epilepsy, works on the principle of producing ketones as the body's main energy source as opposed to glucose by means of a high fat diet with limited protein and minimal carbohydrate (CHO). A >90% reduction in seizure frequency ranging from 31% to 86% has been recorded in patients following the KD for 3 months and >6 years respectively. Short- and long-term side effects include dehydration, kidney stones, and restricted growth with 82% of children following the KD for >6 years being under the 10 th centile for height and weight. Side effects of the KD must be weighed up against benefits in terms of quality of life gained through reduction in seizures.
Keywords: Epilepsy, full-fat diet, medical nutrition therapy, restricted carbohydrate diet
|How to cite this article:|
Scrivens SD. Eponyms in medical nutrition and nutraceuticals: The Ketogenic diet for seizure control. J Med Nutr Nutraceut 2014;3:76-8
|How to cite this URL:|
Scrivens SD. Eponyms in medical nutrition and nutraceuticals: The Ketogenic diet for seizure control. J Med Nutr Nutraceut [serial online] 2014 [cited 2020 Feb 22];3:76-8. Available from: http://www.jmnn.org/text.asp?2014/3/2/76/131957
| Introduction|| |
The first reported use of the Ketogenic diet (KD) was in 1921 when an eminent pediatrician claimed that a number of patients had become seizure free following a starvation diet. The KD regained popularity in 1994 as a therapy for drug-resistant epilepsy.
What is the Ketogenic diet?
The KD is 85% full fat, 10% protein (sufficient for growth) and 5% carbohydrate (CHO) with total energy intake restricted to 75% of recommended daily intake (RDI) and fluid intake restricted to 80% RDI.  Similar to the Atkins diet, fat is broken down producing ketones for use in place of glucose as the body's main energy source. Although the precise mechanisms are unknown, ketones can suppress seizures as long as CHO intake is severely restricted. The KD is not nutritionally complete and must be supplemented with sugar-free vitamins and minerals. If a patient is seizure-free without medication for 1 year or longer, the fat to protein plus carbohydrate ratio may be adjusted down gradually before weaning off over a nominal 6-month period at which time normal diet can be introduced.
Who is the Ketogenic diet intended for?
The KD is a therapeutic diet prescribed and supported by specialist physicians or dietitians for treating children (or less commonly adults) with intractable epilepsy (multiple seizures uncontrolled by one or more medications where surgery is not an option). 
What is the evidence for the efficacy of the Ketogenic diet?
Establishing the efficacy of the KD is fraught with problems. Patients are often prescribed the KD alongside one or more anti-epileptic medications. The majority of studies to date have been observational and tend to reflect outcome of patients willing or able to tolerate the diet with high dropout rates positively skewing data in favor of the KD.  The largest prospective study to date (n150 with 25 dropouts) recorded 3% of patients seizure free, 31% with >90% seizure reduction and 26% suffering 50-90% fewer seizures at 3 months.  At 12 months, 7% of patients remaining on the diet (n83) were seizure free with those achieving >90% seizure reduction and 50-90% seizure reduction falling to 20% and 23% respectively. Similar results were achieved in a multicenter study (n51) following the same protocol. A retrospective review conducted by Johns Hopkins Hospital, Baltimore identified 28 children out of 386 who had followed a ketosis-inducing (n19) or other ketogenic diet for ≥6 years.  At 6 years, 86% of children had >90% reduction in seizures. A Cochrane review (2012) concluded that in cases of intractable seizures, the KD could improve seizure control. 
What is the evidence for the safety of the Ketogenic diet?
As with the Atkins Diet for weight loss, concerns have been raised regarding potential side effects of the KD. Although historically followed for less than 2 years, evidence of the diet's efficacy in reducing number of seizures has led to its use for indefinite periods particularly since the 1990s. Side effects can therefore be divided into short and long term.
Short-term side effects
Common side effects of the KD include dehydration, hypoglycemia, gastrointestinal disturbance, and kidney stones, all of which can be monitored and treated as required along with nutrient supplementation. 
Long-term side effects
A number of studies have raised concerns regarding the long-term effect of the KD on growth (weight and height), bone health, skeletal fracture, liver function, and dyslipidemia. ,, In addition to identified treatable side effects such as kidney stones and constipation, "height and weight less than 10 th centile" was identified in 82% of children following the diet for >6 years increasing from 36% and 50% at baseline respectively (although height and weight percentiles were proportional) and 21% had suffered skeletal fracture.  In line with the Atkins Diet for weight loss, adverse effects on lipid profile were rare.
| Conclusion|| |
The known short- and long-term side effects of the KD must be weighed against the benefits of significant improvements in seizure control and quality of life often seen in patients who are able to tolerate the diet. Alternative versions of the diet with less energy and fluid restriction are being practiced to address nutritional and growth issues but a requirement remains for further studies to establish the long-term effects of the KD and other anti-seizure diets.
| Reflections|| |
The decision to follow the Ketogenic Diet should not be taken lightly and should be prescribed by a physician and followed strictly under the guidance of a specialist dietitian or any seizure control benefits may be temporarily lost. A diet that primarily comprises high fat foods is unpalatable to many people and compliance is generally higher when the diet is introduced at a young age. Where significant reduction in seizures is achieved, it is possible in most cases to reduce or eliminate anti-convulsants, which are frequently associated with undesirable side effects including drowsiness, aggression and learning impairment.  Despite the potential of significant side effects and being a complex diet to follow, the KD has significantly improved quality of life for many families where anti-convulsant medication alone has failed.
| References|| |
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