Thats strange as I read only yesterday that juvenile epilepsy treated by low carb diets was actually quite rare and only considered when drugs had proved ineffective so we're talking about a relatively small number of children, and that most children were on the diet for a year or less. And for that reason there was no long term research carried out. It is thought that ketones have some effect on the part of the brain responsible for seizures, though it is not fully understood. Long term however the resticted insulin caused retarded growth problems, not good in children, bone fractures and kidney stones were also common. Quote from Wikipedea, just found it: Long-term use of the ketogenic diet in children increases the risk of retarded growth, bone fractures and 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 1 in 20 children on the ketogenic diet will 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. Johns Hopkins Hospital now gives oral potassium citrate supplements to all ketogenic diet patients, resulting in a sevenfold decrease in the incidence of kidney stones. However, this empiric usage has not been tested in a prospective controlled trial. Kidney stone formation (nephrolithiasis) is associated with the diet for four reasons: 1. 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. 2. Hypocitraturia: the urine has an abnormally low concentration of citrate, which normally helps to dissolve free calcium. 3. The urine has a low pH, which stops uric acid from dissolving, leading to crystals that act as a nidus for calcium stone formation. 4. 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 adults, common side effects include weight loss, constipation, raised cholesterol levels and, in women, menstrual irregularities including amenorrhoea. So seems to back up what I read yesterday. I also read that it was difficult to stay in ketosis for longer than six to twelve months without reducing the amount of protein as well as carbs as after this time the body, which doesnt actually like being in ketosis, tends to start using the protein source for its energy.