 The day before admission to hospital , the proportion of carbohydrate in the diet may be decreased and the patient begins fasting after his or her evening meal . On admission , only <unk> and caffeine @-@ free fluids are allowed until dinner , which consists of " eggnog " restricted to one @-@ third of the typical calories for a meal . The following breakfast and lunch are similar , and on the second day , the " eggnog " dinner is increased to two @-@ thirds of a typical meal 's caloric content . By the third day , dinner contains the full calorie quota and is a standard ketogenic meal ( not " eggnog " ) . After a ketogenic breakfast on the fourth day , the patient is discharged . Where possible , the patient 's current medicines are changed to carbohydrate @-@ free formulations . 
