You’ll quickly find that salads are your friend when in ketosis, and for a good reason: they provide lots of food to fill you up, but they’re not going to bog you down. A bed of spinach with some red onion, bacon, a little tomato, and a hot sauce vinaigrette is quick and delicious. Add in some protein – perhaps that leftover salmon from day 1 – and you’ve got a complete, healthy lunch.
Achieving optimal ketosis hinges on finding the right balance of macronutrients (or “macros” in keto-speak); these are the elements in your diet that account for the majority of your calories, a.k.a. energy—namely, fat, protein, and carbohydrates. By the way, it’s often “net grams” of carbohydrates that are counted toward your daily intake; “net” deducts the amount of fiber in a food from its carbohydrate total.
Physicians of ancient Greece treated diseases, including epilepsy, by altering their patients' diet. An early treatise in the Hippocratic Corpus, On the Sacred Disease, covers the disease; it dates from c. 400 BC. Its author argued against the prevailing view that epilepsy was supernatural in origin and cure, and proposed that dietary therapy had a rational and physical basis.[Note 3] In the same collection, the author of Epidemics describes the case of a man whose epilepsy is cured as quickly as it had appeared, through complete abstinence of food and drink.[Note 4] The royal physician Erasistratus declared, "One inclining to epilepsy should be made to fast without mercy and be put on short rations."[Note 5] Galen believed an "attenuating diet"[Note 6] might afford a cure in mild cases and be helpful in others.
The ketogenic diet is calculated by a dietitian for each child. Age, weight, activity levels, culture, and food preferences all affect the meal plan. First, the energy requirements are set at 80–90% of the recommended daily amounts (RDA) for the child's age (the high-fat diet requires less energy to process than a typical high-carbohydrate diet). Highly active children or those with muscle spasticity require more food energy than this; immobile children require less. The ketogenic ratio of the diet compares the weight of fat to the combined weight of carbohydrate and protein. This is typically 4:1, but children who are younger than 18 months, older than 12 years, or who are obese may be started on a 3:1 ratio. Fat is energy-rich, with 9 kcal/g (38 kJ/g) compared to 4 kcal/g (17 kJ/g) for carbohydrate or protein, so portions on the ketogenic diet are smaller than normal. The quantity of fat in the diet can be calculated from the overall energy requirements and the chosen ketogenic ratio. Next, the protein levels are set to allow for growth and body maintenance, and are around 1 g protein for each kg of body weight. Lastly, the amount of carbohydrate is set according to what allowance is left while maintaining the chosen ratio. Any carbohydrate in medications or supplements must be subtracted from this allowance. The total daily amount of fat, protein, and carbohydrate is then evenly divided across the meals.