Insulin, sulfonylureas, and glinides should be progressively reduced by about 50%; biguanides, DPP-4 inhibitors, and GLP-1 agonists should be considered as optional; SGLT2 inhibitors are associated with a risk of ketoacidosis in some T2D patients with relative insulin deficiency and should therefore be avoided during a KD. This evidence concerns the gene SLC5A2 and type 2 diabetes mellitus.