The nutritional adequacy of the ketogenic diet in paediatric epilepsy: Detailed nutrient analysis and dietary recommendations

Background and aims

Much of the focus of ketogenic diet (KD) literature has been on the macronutrient profile, as the appropriate distribution of carbohydrate, fat and protein is essential to inducing ketosis. Few studies have evaluated the micronutrient adequacy of the KD in paediatric epilepsy, despite the importance of adequate vitamin and mineral intake in growth and development. Our study evaluated the nutritional adequacy of the Modified Atkins Diet (MAD) and Classical Ketogenic Diet (CKD) in children with epilepsy, relative to baseline diets and Nutrient Reference Values (NRVs).

Methods

Twenty children with epilepsy on the MAD and CKD underwent dietary analysis of 28 key nutrients at baseline and 3 months on diet ( ± multivitamin). Nutrient intake was expressed as % relative to recommended daily intake (RDI), adequate intake (AI), and upper limit as per the Australian NRVs. Nonparametric statistical comparisons were performed with a significance of p < 0.05.

Results

Sixty percent of children were KD ‘responders,’ exhibiting >50 % seizure reduction with median beta-hydroxybutyrate (blood ketone) level of 2.75 mmol/L on MAD and 4.25 mmol/L on CKD. Despite restriction of fruits, vegetables, dairy and wholegrains, children on MAD (without multivitamin) met 100 % of RDI for all nutrients except potassium. Intake of fibre and polyunsaturated fat increased significantly on the MAD compared to baseline. With multivitamin supplementation, some children on MAD were close to meeting upper limits for vitamin A, zinc, and selenium. Dietary recommendations to optimise nutritional adequacy using a ‘food-first’ ketogenic approach are provided.

Conclusions

Although it is commonly reported that the restrictive nature of the KD induces nutritional deficiencies, our findings indicate that a well-designed MAD can induce positive dietary changes including increased fibre intake, increased mono- and polyunsaturated fat intake, and increased omega-3 essential fatty acid intake in children with epilepsy, whilst producing adequate ketosis.