Introduction and objective:
Nephrolithiasis is a common disease worldwide, and its incidence trend is increasing due to, among other things, an aging population or climate change. Diet is an important factor influencing the risk of the disease; therefore, the purpose of this review article is to evaluate the impact of the ketogenic, low-carbohydrate diet, strongly gaining popularity, on the development of kidney stones.

Brief description of the state of knowledge:
In kidney stones substances are deposited in the kidneys or urinary tract. Substances which contribute to the formation of kidney stones include oxalate, calcium phosphate, and uric acid. Inhibitors of kidney stone formation, such as citrates, magnesium compounds, also play a very important role in the formation of deposits. The ketogenic diet involves reducing the intake of carbohydrates in favour of more fats and protein, and can be applied to people suffering from epilepsy or obesity. According to scientific studies, including mainly paediatric patients suffering from epilepsy, following a ketogenic diet carries an increased risk of kidney stones as a consequence of, among other things, a decrease in urinary pH, hypocytraturia, hypercalciuria or increased uric acid levels. Possible causes may be found in dietary ingredients – meat rich in purines, or nuts containing significant amounts of oxalates.

Summary:
The ketogenic diet may increase the risk of kidney stone formation. However, studies concerning this scope of problems have been conducted on a too small group of subjects (mainly children with epilepsy) to be able to clearly refer the results to a larger, general population.