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.[19] On admission, only calorie- and caffeine-free fluids[37] are allowed until dinner, which consists of "eggnog"[Note 8] 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.[19]
You want to keep your cheats to none. Be prepared, make sure you’re eating what you need to be satiated (“full”), and make sure you’re satisfied with what you’re eating. If you have to force yourself to eat something, it will never work out in the end. This is just a guideline on how you can eat on a ketogenic diet, so you’re very welcome to change up what kind of foods you eat!
The transition process can be hard, especially when moving away from a diet that is normally carbohydrate heavy. This can sometimes bring on flu-like symptoms for a couple of days – ‘keto flu’ is a thing! Symptoms of the 'keto flu' include brain fog and fatigue, moodiness, migraines, and muscle cramping or tightness, which usually occur as a result of electrolyte changes or dehydration.

In many developing countries, the ketogenic diet is expensive because dairy fats and meat are more expensive than grain, fruit and vegetables. The modified Atkins diet has been proposed as a lower-cost alternative for those countries; the slightly more expensive food bill can be offset by a reduction in pharmaceutical costs if the diet is successful. The modified Atkins diet is less complex to explain and prepare and requires less support from a dietitian.[55]
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