Ketogenic diet has been used in treating epilepsy for more than 80 years. It is based on a drastic change of proportions in the consumption of carbohydrates, proteins and fats. In everyday diet we consume approximately 34 per cent of fats, 50 per cent of carbohydrates and 14 per cent of proteins. While ketogenic diet consists in 80-90 per cent of fats and in 10-20 per cents of carbohydrates and proteins together. Despite its indisputable effectiveness, the functioning of the ketogenic diet has not been explained. It seems that its functioning mechanism is unique and results from a number of chronic metabolic changes as well as the adaptation in the cenral nervous system that occurs during its long-term application. The most recent clinical and experimental data suggest that the ketogenic diet also has neuroprotective properties, which makes it a useful alternative therapeutic method in the modification of the natural history of the diseases related with neurodegeneration processes.