Ketogenic diet is certainly a very controversial and very popular topic both in science and in social media discussions today. There are many defenders and people who criticize at the same time. But what, in fact, is the ketogenic diet?
Although there are different protocols, the ketogenic diet itself is characterized by a restriction of carbohydrates with up to a maximum of 50 grams per day so that the body does not have enough glucose and / or glycogen to supply the cells. This will trigger low insulin secretion, which in turn will not be able to inhibit lipolysis in adipose tissue. Thus, there is a flow of free fatty acids to the liver, which transforms these fatty acids into ketone bodies so that they can be transported in the bloodstream without influencing the pH. The ketone bodies then reach the peripheral organs to be used as an energy substrate.
The different protocols alter the protein supply (some hyper, others normal), others alter the caloric value (hypo or normal), there is differentiation in the sources of fat and protein … but in general the basis is the same: induce a metabolic state that mimics ketosis.
In the long run, on the other hand, there are no studies that evaluate results and safety. What we have evidence comes from studies with refractory epilepsy, a condition in which ketogenic is indicated as a treatment. In one study, 141 children with refractory epilepsy and a mean age of 7.1 years adopted a ketogenic diet for approximately 16 months. Of these, 3 showed elevated liver transaminases (indicating some degree of liver damage), 3 developed hepatic steatosis and 2 developed cholelithiasis. Thus, the authors suggest that patients on continuous use of this type of diet should be monitored periodically through laboratory exams and abdominal ultrasound to track these side effects .
Of course, these data cannot be fully applied to adults without chronic diseases or with different diseases, the population is different. But until long-term studies with adults (especially obese, who already have risk factors for hepatovesicular damage), these studies serve to raise hypotheses and to be cautious. Monitoring must be continuous!