SLC2A1 and epilepsy: To achieve a level of ketosis adequate for seizure control (in epilepsy) and for ketone use as an alternative fuel for brain metabolism (in GLUT1-DS), very low amounts of carbohydrates, adequate amounts of protein, and very high amounts of fat must be prescribed in a rigidly controlled ratio (ketogenic ratio)—resulting in a highly unbalanced diet compared to WHO recommendations for children and adolescents [21,22,23,24,25].