Apparently, diabetic children on ketogenic diets for 6 years are at a substantially increased risk for developing kidney stones: http://perfecthealthdiet.com/?p=1177 What might be causing this and what can be done to ameliorate such a risk?
Personally, I was wondering if part of the problem might have been PUFA intake. These diets are ketogenic but not paleo and many people think PUFA and grain oils are the healthier fats so the general populace would probably be targeting these kinds of fats. Plus the consumption of mostly muscle meats is likely with little to no emphasis on organ meats. Fruit intake would be nonexistant and veggies are not universally liked. Seems like an easy recipe for a diet that in some cases would be deficient in some important nutrients like magnesium. Of course, then all ketogenic diets are then blamed as dangerous when it could be simply an issue of imbalance and lack of certain nutrients, probably those that co occur with carbs but would exist in higher quantities in the less favored types of meat like grassfed or organ meats. Since neither the innuit nor the masai have a big problem with kidney stones, then it's probably not the ketogenic diet itself that is the problem. I think the scientists are missing the important point of all the clues they have been given about what may cause kidney stones. They are assuming it is the ketogenic diet itself but not looking beyond that to reasons why it may not be. IMO, what they should be looking for is what is diff about the diets of these kidney stone patients compared to other ketogenic diets that do not result in kidney stones.
"...what can be done to ameliorate such a risk?
In order to ameliorate the risk, doctors at Johns Hopkins Hospital, where this treatment was invented, give large amounts of potassium citrate to these children as a preventative measure. The standard dose is 2 mEq/kg per day.
This is a very large dose. For a 150 lb adult, it would be nearly 15 grams per day. That's the amount in an entire bottle of over-the-counter potassium citrate capsules sold in US drugstores.
These large doses are given under a doctor's supervision.
It should be noted that these children are on medical ketogenic diets. Ketosis is a matter of degree. These children are in deeper ketosis (in other words, they have higher levels of ketones in their blood) than people on ordinary paleo diets.
The classical medical ketogenic diet is much more extreme than a paleo diet or intermittent fasting or even Atkins induction. Most of these kids eat 90% of calories as fat. Their overall calories are restricted and their protein is restricted. (Why restrict protein? Because the body turns surplus protein into glucose which reduces ketosis.)
Reference: McNally et al. Empiric use of potassium citrate reduces kidney-stone incidence with the ketogenic diet. Pediatrics 2009 Aug;(2). http://www.ncbi.nlm.nih.gov/pubmed/19596731
My recollection is that the theory is high protein + low water intake that contributes to it due to a higher uric acid load. The way to resolve it was to drink more water to make sure the uric acid was diluted. This can be difficult dealing with kids though.
I've seen lots of anecdotal advice to drink lemon juice or apple cider vinegar because they have lots of citric acid, which will dissolve the calcium stones. Of course, I've never seen this tied to any kind of study, but it seems like an easy preventative measure to experiment with.