Understanding the core principles of a 'modified ketogenic diet': a UK and Ireland perspective.

BACKGROUND: Many centres across the UK and Ireland anecdotally report using a 'modified ketogenic diet' (MKD) as a treatment for refractory epilepsy. Although a MKD is within the spectrum of ketogenic diets (KDs), there is little literature reporting upon its definition, use or clinical effectiveness. We aimed to understand the core principles of MKD practice and to assess whether and how the MKD differs from other KD protocols. METHODS: An online survey, designed by a consensus group of ketogenic dietitians, was circulated to 39 KD centres across the UK and Ireland. It consisted of 35 questions regarding dietetic practice when providing MKD. RESULTS: Eighteen centres completed the questionnaire: 13 paediatric, three adult and two combined centres. All dietitians based MKD 'prescriptions' on estimated total energy requirements. The average macronutrient profile was 75% fat and 5% carbohydrate, with protein ad libitum. Carbohydrate and fat targets were implemented via weighed portions (carbohydrate lists n = 18; fat lists n = 13) and 'household measures' (carbohydrate lists n = 2; fat lists n = 3). Of the centres, 94% (n = 17) adjusted macronutrients over time; these decisions were based on ketone levels and seizures in most cases (83%; n = 14). Ketogenic nutritional products available on prescription were used by 10 centres (56%) when initiating and by all centres when 'fine-tuning' the MKD. CONCLUSIONS: A modified ketogenic diet in the UK and Ireland is a hybrid KD, adopting principles from other established KD protocols and defining new elements unique to the MKD. Further research into the clinical and cost-effectiveness of MKD would be of benefit.

Carnitine, nutritional supplementation and discontinuation of ketogenic diet therapies.

Nutritional adequacy of a prescribed diet is integral to clinical implementation of the ketogenic diet therapies in intractable epilepsy. This review discusses the evidence for using additional carnitine and the importance of full micronutrient supplementation. The optimal duration of a diet therapy is also discussed, drawing on results of an internationally applied questionnaire.

The effect of the classical and medium chain triglyceride ketogenic diet on vitamin and mineral levels.

BACKGROUND: The risk of nutritional deficiency in children on restrictive dietary treatments and a lack of ketogenic diet (KD)-specific UK supplements raises concerns about micronutrient status. Vitamin A, E, zinc, selenium and magnesium levels were therefore examined in children with intractable epilepsy treated with the KD. METHODS: Plasma vitamins A and E, zinc, selenium and magnesium levels were measured at baseline and after 3, 6 and 12months on the classical (n=46) or medium chain triglyceride (MCT) (n=45) KD in children aged 2-16years, as part of a randomised trial, and pairwise comparisons with baseline were performed. RESULTS: Data were available from 91 children. From baseline to 12months, mean plasma vitamin A decreased from 1.41µmol L(-1) to 1.13µmol L(-1) in the classical group (P<0.001) but increased from 1.52µmol L(-1) to 1.81µmol L(-1) in the MCT group (P<0.001). Mean plasma vitamin E increased from 22.7µmol L(-1) to 33.2µmol L(-1) in the classical group (P<0.001) and from 22.3 µmol L(-1) to 23.3µmol L(-1) in the MCT group (P<0.05). No significant change in plasma zinc was seen at 12months, although mean plasma selenium decreased from 0.95µmol L(-1) to 0.88µmol L(-1) in the group as a whole (P<0.05). Mean plasma magnesium decreased from 0.87mmol L(-1) to 0.83mmol L(-1) in the group as a whole (P<0.001); when subdivided by KD type, this was limited to the classical group. CONCLUSIONS: Changes in plasma vitamins A and E and the decline in magnesium status after 12months of KD treatment suggest that micronutrient status may be suboptimal in this group and that available formulations for KD supplementation may need reviewing.

Efficacy of dietary treatments for epilepsy.

The ketogenic diet (KD) is a high fat, restricted carbohydrate regime that has been used as a treatment for seizures since the 1920s, when it was designed to induce a similar metabolic response to fasting. A modification of this early classical version of the KD was introduced in the 1970s using medium chain triglycerides as an alternative fat source. More recently, two alternative, less-restrictive dietary treatments have been developed: the modified Atkins diet and the low glycaemic index diet. There are many case reports and observational studies reporting successful use of the KD, and a growing number of studies reporting similar success with the modified Atkins protocol. A recent randomised controlled trial has shown a significant benefit of the KD compared to no change in treatment. The use of these dietary therapies in the UK is supported by literature evidence, although often is limited by a lack of resources; increasing awareness and knowledge is fundamental to ensure availability for those individuals with intractable epilepsy who may benefit from them.

The ketogenic diet in childhood epilepsy: where are we now?

The ketogenic diet is a therapeutic dietary treatment for epilepsy in children which is resistant to medication. Until recently, evidence for use and resources available has been sparse. This review aims to provide a summary of the evidence supporting its use in children, some guidance towards its implementation and the services currently available in the UK.