9.6.11

3 year experience on Ketosis and low carbs

Dr Kurt Harris - a detailed account of his 3 year experience experimenting with low carb and ketosis:

Archevore - Archevore Blog - Thoughts on Ketosis - I
Archevore - Archevore Blog - Thoughts on Ketosis - II

(cf: his more hard-line position as in August 2009: here)

Random extracts follow:

I've never advocated anyone eat VLC, only described that I often did. It is not necessary to eat VLC to stop the metabolic damage of the SAD. VLC might only be necessary if you have diabetes or need to lose a lot of weight. PaNu is not intrinsically a weight loss prescription. It is not therapy. It is just eating in a non-damaging way.

I don't routinely measure my CHO intake or anything else. Everyone will want to know, so I will say that my purely speculative idea is that as long as there are enough animal foods in the diet, a range of 15 to 60% carbohydrates (exact numbers not important) are probably all equally healthy as long as the NAD are avoided.

I intend to keep eating at least 20% starch, which is twice the Kwasniewski number, to give myself a buffer against ketosis and because I speculate that this is about the level at which your glycogen stores start to get optimized. I certainly feel that way. The post-workout orthostasis is completely gone*.

Oh, and Rice Krispies (of whatever brand) have have only a few grams of added sugar in a bowl. It's really just toasted white rice. A good sized bowl is maybe 40 g of starch, a few grams of sugar, plus whatever lactose if you add H/H or milk. For lunch and/or dinner add sweet potatoes, white potatoes and whatever green veggies and dessert fruit you eat and that should do it

I have yet to see formal evidence that ketosis is metabolically stressful. When the body enters the least metabolically favorable scenario (starvation) ketosis is developed. It doesnt make sense that ketosis would be developed to be more stressful.
KGH: It is developed to spare our structural proteins and conserve precious glucose for the brain, whether it is "stressful" or not. It certainly involves extra metabolic work. The fact that this happens only when we deprive our bodies of dietary glucose suggests it is stressful. It happens to spare our glycogen - the body is detecting that the glucose reserves are threatened. And it either spares our own muscle or reduces our demand for extra dietary protein to turn into glucose.
Finally, ketonuria does not always correlates to ketonemia.
KGH: Agreed but not my point. Once you are keto-adapted after a few weeks, if you have ketones in the urine it means you are in ketosis enough that you are making more than you burn.

Ketosis is an adaptive state that beats the alternative of glycogen depletion or muscle wasting that it is designed to counter. This makes it "good". In the same way, muscle wasting to keep your brain supplied with glucose is "good". Good in the sense of beating the alternatives. That does not mean we should seek to live continuously in either state, though does it?

For a good discussion of mostly short term adverse effects of ketosis, based on a conversation I had with Peter a while ago, you can go here.

I will allow that there could be theoretical benefits to spending some time in ketosis. And there are therapeutic uses of ketogenic diets for people who are sick. But those who propose that a metabolic state that evolved as a response to a dietary deficiency is per se a desirable state to be in all the time have the burden of proof. This is the same burden of proof faced by those advocating anything that is outside the known evolutionary history of our species.

Synthetic resveratrol, megadoses of fish oil, 10,000 units a day of vitamin D year-round, statins, deriving the majority of your fuel needs from coconut oil, any supplement to a real food diet - for all of these things the advocates have the burden of proof.

So, once more for emphasis. Ketosis* can be useful therapeutic maneuver, but there is no evidence using current knowledge of metabolism or evolutionary reasoning that we should strive to be in this atypical state all the time.

* I define Ketosis in the usual paleosphere way. Eating a low enough digestible carbohydrate intake to induce serum levels of ketones much higher than those eating a carbohydrate replete diet. This will usually be a carbohydrate intake below the amount that would be necessary to run your brain on nothing but glucose, but still higher than the basal glucose requirement of the brain once keto-adapted, where the brain is running as much as half on ketones. We usually use ketones in the urine (ketonuria) as evidence of ketosis, but this is not 100% reliable, as the rate they are burned influences how many are spilled into the urine. The carbohydrate amount necessary to keep out of significant ketosis varies, but Kwasniewski uses 10% of kcal, and Lutz uses 70 g/day which is roughly the same if you are 2800 kcal/day but more if you eat less. Bernstein uses 30g/day for his diabetes diet, but this is meant to ensure micronutrient intake from non-starchy veggies and will not keep you out of ketosis.