kidney stones. The diet reduces levels of insulin-like growth factor 1, which is important for childhood growth. Like many anticonvulsant drugs, the ketogenic diet has an adverse effect on bone health. Many factors may be involved such as acidosis and suppressed growth hormone. About one in 20 children on the ketogenic diet develop kidney stones (compared with one in several thousand for the general population). A class of anticonvulsants known as carbonic anhydrase inhibitors (topiramate, zonisamide) are known to increase the risk of kidney stones, but the combination of these anticonvulsants and the ketogenic diet does not appear to elevate the risk above that of the diet alone. The stones are treatable and do not justify discontinuation of the diet. Around half of clinics gives oral potassium citrate supplements empirically to all ketogenic diet patients, with some evidence that this reduces the incidence of stone formation. However, has not been tested in a prospective controlled trial. Kidney stone formation (nephrolithiasis) is associated with the diet for four reasons: Excess calcium in the urine (hypercalciuria) occurs due to increased bone demineralisation with acidosis. Bones are mainly composed of calcium phosphate. The phosphate reacts with the acid, and the calcium is excreted by the kidneys. Hypocitraturia: the urine has an abnormally low concentration of citrate, which normally helps to dissolve free calcium. The urine has a low pH, which stops uric acid from dissolving, leading to crystals that act as a nidus for calcium stone formation. Many institutions traditionally restricted the water intake of patients on the diet to 80% of normal daily needs; this practice is no longer encouraged. In adolescent and adults, common side effects reported include weight loss, constipation, dyslipidemia, and in women, dysmenorrhea. Implementation The ketogenic diet is a medical nutrition therapy that involves participants from various disciplines. Team members include a registered paediatric dietitian who coordinates the diet programme; a paediatric neurologist who is experienced in offering the ketogenic diet; and a registered nurse who is familiar with childhood epilepsy. Additional help may come from a medical social worker who works with the family and a pharmacist who can advise on the carbohydrate content of medicines. Lastly, the parents and other caregivers must be educated in many aspects of the diet for it to be safely implemented. Implementing the diet can present difficulties for caregivers and the patient due to the time commitment involved in measuring and