The purpose of the thesis was to describe the use of a low-carbohydrate diet as a support in the treatment of epilepsy. The goal was to provide information about the low-carbohydrate diet as an adjunctive therapy for epilepsy. The research questions were: 1. How is the low-carbohydrate diet related to epilepsy? 2. What are the benefits of the low-carbohydrate diet in the treatment of epilepsy? 3. What kind of side effects can a low-carbohydrate diet have in the treatment of epilepsy, and how can they be prevented?

The thesis was conducted as a descriptive literature review. Literature search was carried out using domestic and international databases. The data were analyzed through a content analysis approach, and the quality was assessed using the CASP quality assessment method.

Based on the results of the literature review, comprising five studies, the low-carbohydrate diet (LCD) proved to be effective in drug-resistant epilepsy, especially in children. The diet significantly reduced the frequency of seizures in those unresponsive to traditional medication. The LCD involves restricting carbohydrates to below 60 grams per day, inducing the body to transition into a catabolic state and use fatty acids as an energy source. Although the LCD can improve quality of life, its mechanisms are not fully understood. Practical guidance is crucial, but further research is needed to better understand the effects of the LCD and identify suitable patient groups, taking into account potential side effects and precautions.

Suggestions for further research included comparative studies on effectiveness in different forms, the impact on different age groups, tolerability of the diet, long-term monitoring, and the need for more Finnish studies.