Is the horse I’m beating dead, yet?
Well, get it while it’s hot, I guess. Dogpile!
And, what with Chris Kresser (Is a Low-Carb Diet Ruining Your Health?) and Tom Naughton (Reactions To Arguments About Ketosis) displaying increasing skepticism over the healthfulness of very low carbohydrate and/or ketogenic diets in perpetuity, let’s just keep putting fuel on the fire, shall we?
I’ve been lightly participating in both comment threads linked above; rather politely, too. There was a comment by “Damocles” this morning I found interesting and to me, offered a clue as to why so many defend ketosis in spite of what it does to glucose tolerance (See Inuit and Stefansson).
From an evolutionary perspective, it makes perfect sense for the body to increase insulin resistance during ketosis.
Its a signal for the body that carbs are very scarce at the moment. So by increasing insulin resistance, cells wich can well burn lipits and ketons refuse to snatch the glucose from the blood, – leaving more for the most important organ: the brain.
As the brain needs (even in ketosis) a certain amount of glucose to funtion.
The insulin resistance in ketosis is a smart allocation of glucose (to the brain), when carbs are coming available, and to not have to rely on gluconeogenesis from proteins.
When carbs come available again regularily, the insulin resistance can be reduced, so all the other cells can uptake this fuel.
Physiologically, he’s correct. But here’s the problem.
“From an evolutionary perspective, it makes perfect sense for the body to increase insulin resistance during ketosis.”
Yes, this is all very well known and understood, including the fact that some textbooks (I used to have a handy reference) indicate that after a time of adaptation, the brain’s absolute glucose requirement goes down (like from 120-130g per day to ~60).
Here’s your blind spot, though, in my view. This is not an adaptation to ketosis. It’s an adaptation to STARVATION. Ketosis itself is a physiological adaptation to starvation. So-called nutritional ketosis is really a hack designed to get a person into ketosis by means other than fasting or chronic starvation, and in a very odd way: restriction of not just carbohydrate to near nil, but restriction of protein as well. Stop and think about it. How does that even pass anyone’s smell test as a desirable daily state?
I concede that long-term ketosis likely has some therapeutic value, as do a number of pharmaceuticals and other therapies when properly prescribed by a clinician with LOTS OF EXPERIENCE. I also concede, in fact strongly support, the notion that episodic ketosis is likely very beneficial. Autophagy. It’s called fasting and just about every religious tradition includes it in some way for good reasons having nothing to do with pleasing doG.
But, chronic starvation is a bad idea, a priori. I suspect chronic ketosis to model a starvation state through restriction of both carbohydrate and protein at the same time, requiring upwards of 80% fat—that’s pretty vapid in terms of micronutrients—to be an equally bad idea for the vast majority of people the vast majority of the time.
This really falls under the “extraordinary claims” clause. As ought anything so unnatural on its face.
By total happenstance, I got an email from Duck a while later. A link to a review paper from 2003: Low-carbohydrate diets: what are the potential short- and long-term health implications? (Shane A Bilsborough MSc (Nutrition) and Timothy C Crowe PhD; School of Health Sciences, Deakin University, Burwood, Australia).
I found the section Potential short-term health implications - Ketosis on page 398 quite interesting and posted this follow-up comment (still in Tom’s moderation queue at the time of this drafting).
Duck emailed a paper earlier and guess what I happened upon (emphasis mine)?
Studies examining the long-term safety of ketogenic diets are few in number with most of the available data coming from the application of ketogenic diets in the treatment of paediatric epilepsy.18 The diet used in this patient group is a high-fat, adequate protein, low- carbohydrate diet designed to mimic the biochemical changes that occur during starvation. Studies of children who have followed a ketogenic diet for management of epilepsy found that about 50% of children will continue on the diet for at least a year.18 Reasons for discontinuing the ketogenic diet were due to either a lack of efficacy or due to the restrictive nature of food choices. Common adverse events attributed to the diet included dehydration, gastrointestinal symptoms, hypoglycaemia, as well as carnitine and vitamin deficiencies. Cognitive effects, hyperlipidaemia, impaired neutrophil function, urolithiasis, optic neuropathy, and osteoporosis have also been reported to occur in some patients following ketogenic diets.19 In addition, elevation of blood uric acid levels is a well-recognised side effect of prolonged ketosis.7
Extraordinary claims demand extraordinary evidence. Can everyone agree that remaining in perpetual ketosis by means of restricting BOTH carbohydrate AND protein in order to “mimic the biochemical changes that occur during starvation” is:
1. A-priori unnatural, since the biochemistry in a state of starvation is not a NORMAL physiological state.
2. An extraordinary claim, when asserted as some sort of optimal diet for long term health or weight maintenance.
…Thus, requiring very extraordinary evidence, up to a standard that ought to be absolute proof. Otherwise, everyone out there doing this “nutritional” ketosis nonsense in perpetuity is conducting a massive experiment with zero basis in natural reality.
Just the word itself is a complete scam. “Nutritional.” Let’s see, restrict both macronutrients with the most vitamins, minerals, phytonutrients, and replace it with the macronutrient with the very least by far of all those things. Call it “nutritional.”
…Alright, now I’m getting angry.
And so, it ought to be renamed so that it’ll at least possess the virtue of honesty: “Nutritional Starvation.” Taking applications now. 50% off until Labor Day.
Here’s one thing to wrap your mind around, in addition to the above. What else goes haywire in a biochemical, metabolic state of starvation besides the glucose tolerance (physiological insulin resistance) that I’ve hammered on over and over (See Inuit and Stefansson)?
We understand why we get insulin resistance on VLC and/or ketogenic. Preserve glucose for the brain. Why? because it’s an absolute requirement and to put it bluntly, our metabolism has evolved to fuck you up in the short-term in order to preserve your long-term survival chances. What else is it willing to fuck you over with in the short term? Speculating, but how about:
- Stress hormones. Keeping you alert and on edge, ready to exploit the most meager source of food?
- Restorative sleep. Good, restful sleep is for the well fed?
That’s just two, but they’re biggies if it turns out to be true. Why? Rapid aging, that’s why. In the very short term, none of this is a problem, it would make you better prepared for survival, etc. Perfect evolutionary sense.
Another commenter (retired doc) suggested that physiological insulin resistance is no big whoop, and you can just cheat on the test.
…The Inuit failing a glucose tolerance test is a normal finding for someone who’s been in dietary ketosis. This is the cause of the carb-induced brain fog. It’s physiological (i.e. a harmless adaptation). If you’re going to have a GTT and are on a ketogenic diet, you should up your carbs to 150g per day for three days. Otherwise, you are going to appear diabetic when you’re not.
That’s a piece of info I picked up on my reading.
Another thing is that someone on a ketogenic diet may have a slightly higher fasting glucose than he did have. Again, a physiological adaptation.
So, instead of jumping to conclusions, as many of the “anointed” do, look this stuff up.
Well, I happen to have very smart, well-studied, laser-sharp commenters who do look stuff up. But, sometimes, they just call BS when they see it. Here’s a regular commenter here, Bret.
To supplement Tom’s reply, it was really Richard’s point that the Inuit were not in ketosis regularly. My point here is that ketosis does not necessarily result in universally excellent biomarkers, the way many unconditional ketosis trumpeters imply. People considering going into chronic ketosis deserve to know the full facts, not just the one-sided view many people give.
On to your retort: So your answer to a post-ketosis BG in the 300s is that the literature says you should up your carbs to 150 g/day for three days? First, I don’t care what any literature says I “should” do. That’s a silly appeal to authority to begin with. Secondly, What is the purpose of a GTT if you are going to modify your normal diet beforehand, other than to pass an insurance physical? Sounds like you’re defending ketosis for the sake of defending ketosis. By the way, what do you think is happening to your BG over those three days, as you prepare for your GTT? If your reaction is like the Inuit’s, then it is hitting the 300s. All to get a good GTT result… Doesn’t sound too smart to me.
Care to elaborate on your point about a higher fasting BG being a physiological adaptation? Much like your previous point, that tells us absolutely nothing useful. Tom’s BG in the 190s was a physiological adaptation of his eating those potatoes. Getting fat from overconsuming refined carbs is a physiological adaptation. Red, inflamed skin from scrubbing yourself with a steel brush is a physiological adaptation. Calling a phenomenon whose cause nobody disputes a physiological adaptation tells us nothing in a debate about the pros and cons of conflicting dietary philosophies. A higher BG is a higher BG in my book, and is not a flattering point in favor of ketosis.
I do not appreciate one bit your suggestion that I have jumped to conclusions, displayed the same attitude as ‘the anointed’, and failed to look this stuff up. Those are all three assumptions, and quite wrong ones, at that.
Of course, in the end it’s always about how it works for you, so here’s how it worked for Kris.
…I had the same exact high blood glucose reactions as you after adding a little too much starch to my diet. Since I was suffering a few side effects of low-carbing, I figured I was destined for diabetes and possibly even insulin injections because I felt I couldn’t stick to it any longer. At first I started experimenting with eating starches such as potatoes or oatmeal for breakfast, but with minimal fat if any at all, and no protein. I found that I was getting lower and more controlled BG readings… in fact lower than when I was on the LC diet. When the negative side effects of low carb began to disappear, I became more and more relaxed about the carb issue. I must admit, I do feel best when keeping wheat to a minimum and getting most of my carbs from fruits and vegetables, although I will eat some sugar on occasion if I feel like it. Now, whenever I test my BG it is consistently normal. When low-carbing my fasting readings were anywhere from 118-125. Now they are 90ish. I am not meaning to encourage you to make any changes if you feel that what you are doing works for you. I just want to let you know the BG readings may be temporary and perfectly normal for a body that is just not used to eating starches and sugar any longer.
How many times have I heard this same story? It’s in the hundreds, now, and it includes literally every friend and family I know that has done LC for a long time and bothered to measure fasting and post-prandial blood glucose. Here’s my reply.
“Now, whenever I test my BG it is consistently normal. When low-carbing my fasting readings were anywhere from 118-125. Now they are 90ish.”
This was my experience, my wife’s…other family members. Essentially everyone I know.
In fact, there is a confirmation bias going on in the LC community and I believe it’s used a bit nefariously by some to promote LC diets.
Suppose you’re a couch potato, overweight, completely out of shape, etc. Suppose further that you’re a member of a group that dub themselves VLE – Very Low Exercise. The aim of this group is to consistently keep your heart rate under 100 so as to avoid becoming a “Palpitator.” Any kind of spike is taken very seriously.
Then one day, the elevator is broken, so you get up off your electric scooter and take the stairs. After several flights you note that your heart is racing, so you get out your meter, insert a testing strip (har har! and low & behold THEY WERE RIGHT! 250 bpm. YOU’RE PRE-PALPITATOR IF NOT FULL-BLOWN PALPITATOR TYPE 2!
YOU CAN NOT TOLERATE EXERCISE AT ALL!
Alright. Keep pounding nails into this Nutritional Starvation coffin, or just bury it alive?