The ketogenic diet simulates a fasting state and works by stimulating the body to generate energy through fat , instead of using carbohydrates. Generally speaking, it consists of eliminating all foods rich in carbohydrates, such as breads, rice and flour and increasing the consumption of proteins and fats.
What are the physiological mechanisms of the ketogenic diet?
The body uses the most readily available energy source. Typically, this is glucose , converted from carbohydrates. If you limit your intake of carbohydrates and replace them with fat , your body will be forced to use fat from food or its stores as energy sources. This process is called ” ketosis ” and the resulting diet is called a ketogenic diet. The degree to which a person needs to restrict carbohydrates varies from person to person.
In the ketogenic diet, lipids are metabolized by the liver and their oxidation generates ketone bodies, which due to the lack of carbohydrates are used by the body as an energy source. The ketogenic diet induces rapid weight loss, partly due to water loss, but also to fat loss .
Eating less energy than you burn will inevitably lead to weight loss. Typically, you get almost 50% energy from carbohydrates and cutting them at least in half is likely to reduce your total calorie intake . But if a person ingests more calories from fat than his body needs, he will still be storing fat anyway .
Find out more about ” Carbohydrates “, ” Ketosis “, ” Atkins Diet ” and ” The danger of weight loss diets “.
What kind of food can be consumed and which should be avoided?
Low-carb, high- fat ingredients that can be eaten freely include avocado, red meat, fish, eggs, cheese, sour cream, oil, butter, nuts and seeds. The person should avoid, or at least strongly restrict, wheat and other grains, potatoes, corn, legumes, beans, milk, most fruits and sugar .
To induce ketosis in someone who consumes 2,000 calories a day, carbohydrates should be restricted to a maximum of 20 to 50g / day. To put this in perspective, a banana contains about 20g and a bagel (a bread product traditionally made from fermented wheat flour in the form of a ring) about 44g. The protein should also be kept in moderate amounts, they can encourage the production of glucose and stop ketosis.
On the other hand, foods that contain carbohydrates are also usually high in fiber , which is important for healthy bowel function and for keeping a person fuller for longer. Every person on a low carbohydrate diet should eat foods rich in fiber, such as vegetables, broccoli, cauliflower, flaxseeds, nuts, coconut and avocado.
Other uses of the ketogenic diet
This diet has existed since 1920, when it was recommended to reduce the epileptic seizures resistant to the treatments of that time, but it fell out of use in the 40’s, when more effective medications for the control of epilepsies began to appear. As there is an excess of lipids, there is an increase in the production of ketone bodies and, consequently, ketosis. These ketone bodies become the main “food” of the brain , instead of glucose , contributing to the treatment of epilepsy attacks .
Reports in the medical literature indicate that 40% to 50% of children with the disease can have more than 50% reduction in crises, which favors the improvement of the process of knowledge acquisition and neuropsychomotor development, in addition to allowing a decrease in doses of medication needed to control crises.
There is no sure evidence that this diet can benefit cancer , although much has been said about it. The carbohydrate is a key nutrient for patients cancer who are at increased risk of malnutrition associated to the disease and treatment. Thus, a balanced diet with an adequate amount of carbohydrates is recommended to avoid malnutrition .
Risks of the ketogenic diet
The classic ketogenic diet consists of 90% lipids and 10% carbohydrates and proteins . As it is a nutritionally unbalanced diet, it is not recommended that the patient use it for more than three years, and specialized monitoring with a multidisciplinary team for clinical and laboratory monitoring is also essential. The use of the ketogenic diet in an indiscriminate manner and without monitoring by a multidisciplinary team, can bring serious health risks .
In the short term, it can lead to dehydration , hypoglycemia (decrease in the normal amount of sugar in the blood ), vomiting and diarrhea . In the medium and long term, may occur dyslipidemia (excess fat in the blood ), hepatic steatosis (accumulation of fat in the cells of the liver ), calculating kidney and metabolic changes such as elevated uric acid and hypocalcemia (lack of calcium in the blood ).
Health risks also depend on the types of food eaten. Eating an unhealthy diet containing a lot of saturated fat can increase the risk of heart disease and stroke