As the ketogenic diet uses lipids rather than carbohydrates as the primary energy source, it is essential that children are screened for disorders of fat metabolism, to avoid a metabolic crisis.1
The absolute and relative contraindications and other pre-existing complications are listed below.
Absolute contraindications:
- Carnitine deficiency (primary)
- Carnitine palmitoyltransferase (CPT I or II) deficiency
- Carnitine translocase deficiency
- β-oxidation defects
- Medium-chain acyl dehydrogenase deficiency (MCAD)
- Long-chain acyl dehydrogenase deficiency (LCAD)
- Short-chain acyl dehydrogenase deficiency (SCAD)
- Long-chain 3-hydroxyacyl-CoA deficiency
- Medium-chain 3-hydroxyacyl-CoA deficiency.
- Pyruvate carboxylase deficiency
- Porphyria
Most of these conditions can be excluded on a routine urine metabolic screen and blood carnitine profile.
Relative contraindications:
- Inability to maintain adequate nutrition
- Surgical focus identified by neuroimaging and video EEG monitoring
- Parent or caregiver hesitance re: fussy eating and potential non-compliance with diet
- Bulbar dysfunction or Gastroesophageal disease -> aspiration risk
Most patients will require a risk assessment of aspiration as fat-aspiration can lead to severe complications, such as fat-aspiration pneumonia, and can be lethal.
Other pre-existing complicating factors to be considered:
- Presence of kidney stones
- Dyslipidaemia
- Liver disease
- Failure to thrive
- Gastroesophageal reflux
- Poor oral intake
- Constipation
- Cardiomyopathy
- Chronic metabolic acidosis
- High carbohydrate content of current medications
- 1Kossoff et al. (2018). Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group. Epilepsia Open, 3(2):175–192.