The ketogenic diet for infants: How long can you go?

•The KD is effectively and safely used in infants showing seizure reduction over > 50% in 48%–80% and seizure freedom in 14%–54%.•The KD is gradually introduced with a fixed fat/ non-fat ratio of 3: 1, modified if necessary without fasting and fluid restriction.•The KD should be used early in specific epilepsy syndromes and genetic etiologies.•Adverse effects in infants are most frequently emesis, hypoglycemia food and liquid refusal, all of them mostly transient and resolvable by dietary adjustments.•Complete weaning from breastfeeding is not necessary as well as breast milk and nursing at the breast can be included into the KD.