The ketogenic diet is based on the consumption of fats. In this are allowed unsaturated fatty acids (dried fruits, seeds, avocado, tofu and olive oil), however it is emphasized higher intake of saturated fatty acids (butter, animal fat, coconut oil, butter, etc.). Proteins are the next macronutrient when considering the daily energy intake quota, poultry meat, fish and red meat in greater quantities than eggs, cheese and milk, and dairy products are recommended. In the end, the carbohydrates remain. Low-carbohydrate vegetables are allowed, i.e. green leafy vegetables, broccoli, cauliflower, asparagus, peppers, onions, garlic, cucumber, mushrooms, etc. In addition to vegetables, preferences are made to wild fruits because they contain a lower proportion of carbohydrates. Finally, it is necessary to establish some dietary patterns in the ketogenic diet:
Standard ketogenic diet:
fats make up 70% of daily energy intake, 20% proteins, and carbohydrates only 10%.
Cyclic ketogenic diet:
includes periods of carbohydrate compensation (after every 5 days the diet is followed by 2 days with an increase in carbohydrate intake).
Ketogenic-oriented diet:
allows the addition of carbohydrates during periods of intense physical activity (25 to 50 g half an hour before training), and a
Ketogenic diet with high protein content:
similar to the standard diet, but the ratio of intake of macronutrients is changed (fats: proteins: carbohydrates = 60:35:5).
Mechanism of Action of Ketogenic Diet
The primary “fuel” of the human body is glucose. Therefore, when glucose reserves are low, as is the case during a ketogenic diet, the central nervous system must find an alternative source of energy. So
the energy source becomes ketone bodies
– acetate, beta-hydroxybutyrate, and acetone.
These molecules under normal conditions are found in the body at very low concentrations (<0.3 mmol/L). Whereas
are similar in structure to glucose
,
have the ability to use a glucose transporter to cross the blood brain barrier to be used as an energy source when
they reach a concentration of 4 mmol/L in the body.
It is believed that this mechanism forces the body, due to lack of glucose, to consume fat reserves and thus reduce the amount of adipose tissue and total body mass. In addition, ketone bodies serve as an alternative energy source for brain metabolism, positive health effects, such as a reduced frequency of epileptic seizures.
Weight Loss in Ketogenic
An extremely important factor
is the time of a given phase of the diet in which the person establishes control over eating habits and continues with a constant decrease in body weight.
For the patient, knowledge
of the flow and duration of the diet itself is extremely important
, and it is necessary to use tools such as equations for predicting the loss of body mass over a given period of time. The loss of body mass at different stages of the ketogenic diet can be effectively predicted through the application of the Wishnofsky equation, which represents a simple mathematical model that predicts weight loss. Deviations greater than 5.8% in women and 6.1% in men are an indicator of non-adherence to the basic principles of diet, and serve as a corrective factor for the person and for their nutritionist to avoid the “accordion” effect.
This equation does not require a large number of variables, which makes it useful for clinical practice as well as to monitor progress and help create an effective program of loss of body mass, especially due to the major problem of obesity in the world. However, it does not take into account the metabolic adaptations that occur in the body, and also does not take physical activity as a
input
in the calculations.
Bibliographic references
Study suggestion: How to prescribe the ketogenic diet? – Science Play
Watch the video on Science Play with Angelo Daher:
Rethinking the use of fat as an energy substrate
Article: Markovikj G, Knights V, JG Kljusurić. Ketogenic Diet Applied in Weight Reduction of Overweight and Obese Individuals with Progress Prediction by Use of the Modified Wishnofsky Equation. Nutrients. 2023; 15(4):927. https://doi.org/10.3390/nu15040927
