We start by explaining what a ketogenic diet is. It is a diet low in carbohydrates and, consequently, high in fat because we keep protein in a range.
The difference between a low-carbohydrate diet and a ketogenic diet is that in the low-carbohydrate diet we usually say that carbohydrates are below 40%. In the ketogenic diet less than 50g per day of carbohydrates are ingested, although this number is random because depending on the person since with those grams of carbohydrates there are people who may not go into ketosis.
When we go into ketosis (because we do not have glucose as an energy supply for the brain) we transform the fatty acids in the liver into ketone bodies that cross the blood-brain barrier to reach the brain. Even so the red blood cells will always be fed with glucose by gluconeogenesis.
This type of diet is widely used for fat loss because some studies have been misinterpreted as meaning that more fat is burned than with other types of diets. It is really so but because we eat more fat and it is the energy substrate that we use but we do not burn the fat from our body’s reserves.
If we really want to force our body to spend the fat reserves we have, we have no choice but to look for a negative energy balance, that is, to ingest less kcal than we consume, to force our body to get rid of the energy it has stored.
Regardless of the diet, we have to be in an energy deficit to lose fat.