Does a healthy ketogenic diet cause irreversible insulin resistance?

(Todd Allen) #22

Jeff Volek video - keto reverses insulin resistance

(Jen ) #23

Just curious if you have consulted an endocrinologist or keto-friendly nutritionist about your concerns?

(Take time to smell the bacon) #24

The kind of insulin resistance discussed in the article is a healthy adaptation to fat-burning, in which (as I understand the article to be saying) muscle cells resist the insulin’s instructions in preference to burning fat, so the glucose level in the blood rises somewhat. That this is a healthy adaptation is shown (again, according to the article) by the fact that HbA1C remains low. This means that the hemoglobin in the red blood cells is not being glycated at a significant rate, despite the somewhat elevated serum glucose. It is not the same thing as diabetes, which is an insulin problem, not a glucose problem (although too high a glucose level becomes a metabolic emergency for the body). The fact that glucose levels decrease after only three days of eating carbs is another sign that this is neither a problem nor the type of insulin resistance that is the result of eating too much carbohydrate.

From the blog article, here is the blogger’s explanation of the phenomenon:

What is happening? Well, the first thing is that LC eating rapidly induces insulin resistance. This is a completely and utterly normal physiological response to carbohydrate restriction. Carbohydrate restriction drops insulin levels. Low insulin levels activate hormone sensitive lipase. Fatty tissue breaks down and releases non esterified fatty acids. These are mostly taken up by muscle cells as fuel and automatically induce insulin resistance in those muscles. . . .

This is patently logical as muscle runs well on lipids and so glucose can be left for tissues such as brain, which really need it. Neuronal tissue varies in its use of insulin to uptake glucose but doesn’t accumulate lipid in the way muscle does, so physiological insulin resistance is not an issue for brain cells.

However, while muscles are in “refusal mode” for glucose the least input, from food or gluconeogenesis, will rapidly spike blood glucose out of all proportion. This is fine if you stick to LC in your eating. It also means that if you take an oral glucose tolerance test you will fail and be labelled diabetic. In fact, even a single high fat meal can do this, extending insulin resistance in to the next day.

. . . . .

This now fits in to an overall pattern. Elevated non esterified fatty acids induce physiological insulin resistance and a higher than expected FBG level. A simple switch to higher carbohydrate eating (in myself) allows the normal underlying pancreatic and muscle function to show. It also fits in with the FBG of 3.5mmol/l found in the carbohydrate fuelled natives in the Kitava studies.

So do I worry about a FBG of over 5.5mmol/l?

Not while my HbA1c is 4.4%.

So the author, himself a Type II diabetic, has concluded that the rise in fasting serum glucose is perfectly normal, and that he is perfectly healthy, despite appearances.

P.S.—I edited the quotation slightly and added emphasis that seems relevant.



I have had my a1c and fasting sugar tested and the results were normal.

Thanks for the suggestion but I have terrible insurance and it doesn’t cover anything but an md unless it was deemed necessary, so I cannot talk to either of those types of specialists. I am also poor.



Thank you. I suppose then it would just depend on whether or not it actually is healthy to walk around with higher than normal blood sugar regardless of how one defines such a state in regards to one’s hba1c. I would like to find some actual science or studies or both that make it crystal clear that there is

A) no negative health effects from running technically pre diabetic blood sugar levels a lot of the time


B) That this is reversible.

Further, what if a non keto person had a fasting blood sugar level of 110 but a low Hba1c? Is this healthy as well? I am feeling like it is my lack of education that makes me confused but I imagine a standard trained md might be out of sorts here too. Pre diabetes is commonly diagnosed with this blood sugar reading. I imagine if one’s md who was not into keto saw one’s fasting blood sugar, as the author put it, “creeping up” to pre diabetic levels, regardless of what kind of diet one was on, they would be concerned. Further the author states in the comments that there are some kind of permanent changes possible (though he is not clear on what he means by this). I so wish there were more studies!!!



Thank you so much. That is very kind of you to try to watch out for my stress level lol!

The page you posted certainly makes me feel better. I am still a little perplexed by the section where he states “The rationale for refeeding is that if you maintain low insulin levels for a long time, your cells may become somewhat resistant to insulins signals…like a muscle atrophying from lack of use.” He doesn’t quite clarify why one would need to do this at all, particularly in light of his later statement …there are simply and absolutely no health objections to long-term keto…"

If there are no health objections to long-term keto, why is refeeding needed to balance insulin sensitivity?

Also interesting to note is that he flatly contradicts the statement by the author of the article (Peter) that “LC eating rapidly induces insulin resistance”. “a long time” is not rapid!

Is the author of the page an actual doctor and the article writer (Peter) just some guy? That would be convenient as I am fine with taking a doctors reassuring words over some guys concerning statements. However if both are legitimate doctors then it is a bit tougher to decide who to listen to…

(Take time to smell the bacon) #28

Yes, more studies would be a good idea. Be aware, however, that even if nutritional science should suddenly become rigorous and data-driven, there is no such thing as certainty in science. At best we can say things such as, “The preponderance of the evidence appears to indicate . . .” and “In 820 cases out of a thousand, we observed . . .”

If your assessment of the evidence as you’ve discovered it, and in particular from blog posts such as this one, leads you to doubt that keto is safe, then I would strongly encourage you to do what you need to do to stay safe and to adopt some other way of eating. For myself, I like having lost 60 pounds and six inches around the waist, even if I never lose any more. I like the way I feel. I like being free of my sugar/carb addiction. I will keep eating keto regardless, unless my metabolic markers fail to improve, in which case I will be looking around for another way of eating. Keto, however, is the only one I’ve seen so far that I like the looks of.



Thanks, I agree with your sentiment but this idea of irreversible insulin resistance is what scares me!

I have had similar fantastic results on the diet and found nothing but good studies and the bad ones talked about reversible problems. I always felt like the diet was basically keeping one’s body in safe mode so to speak. Protects against diabetes and a lot of other ailments.

Now I am looking at a diet that has wonderful results but may permanently impair my bodies ability to handle glucose and may keep my blood sugar chronically high which may be a very bad thing.

Could you please explain your view on how this is not a concern?



This Volek thing you posted is precisely what I have always understood and it is supported by studies. Perhaps this article is flawed and incorrect? All studies I know of show keto reversing insulin resistance, reversing diabetes, etc. This author is the first I’ve heard say “LC eating rapidly induces insulin resistance”. It is the exact opposite of what studies show. If this were true then LC eating could not reverse diabetes or insulin resistance. Unless I misunderstand something, diabetes is caused by insulin resistance, so if someone with insulin resistance started a diet that rapidly induces insulin resistance then this would simply worsen their condition and may even be fatal for those already having these kinds of problems. It certainly wouldn’t help them!

That said, assuming this resistance is not actually rapid at all and so it would help diabetics, what of the high fasting blood sugar? He said it creeps up. Does it stop at some point? What would that mean for a diabetic? They get on keto, it reverses their insulin resistance, lowers their blood sugar, but then it starts creeping back up as their insulin resistance reappears?

I have seen studies that show the insulin sensitivity improvement is temporary. So maybe this author is simply experiencing a return to his pre keto health problems? Maybe cycling keto is the best way to keep these numbers low?

(Richard Morris) #31

Yep. It’s normal. It’s like if you reduce sugar in your diet, eventually slightly sweet food tastes cloying. It doesn’t mean you can’;t eat the food, it just means that you have adapted to having less sweet food. If you were to eat sweet food for a few weeks you will reverse the adaptation. It is similar with physiological glucose sparing.

Dr Joseph Kraft who did over 15,000 oral glucose tolerance tests and developed the oral glucose insulin test in order to identify hidden diabetes described the pattern when people make insufficient insulin such as in the case of type 1 diabetes as pattern 5


Interestingly, Kraft also shows that sometimes people on low carb diets can show this pattern temporarily. It’s not that they are unable to produce insulin, it’s just more likely that they can take up glucose into cells (eg, brain) without insulin in the first instance. These people return to Pattern 1 after a period on a higher carb diet. I think this is also consistent with the finding that people on LCHF diets typically have a temporary diagnosis of peripheral insulin resistance which is resolved after a large carb meal. It’s likely that the body adapts to preferentially shunt the available glucose to the brain first. So Pattern 5 with a low carb diet is OK, its just the same physiology as Pattern 1 but adapted to low carb.

There are Vegan activists (like Dr Michael Greger) who use this to make their case that a ketogenic diet is unhealthy. IMO It’s a willful misrepresentation of the data in order to make their case that eating animals is unhealthy. Those are the only people I have ever seen make the case that a low carb diet causes diabetes.

Have the keto experts talked about negative effects of "intramyocellular lipids" (IMCLs)

There are a number of people on here, who preKeto had FBG of 120 or more. They now have FBG of 80 or 90. For those people it does not matter whether they will ever be able to process carbs because they could not do it before, its like the joke, Doctor will I ever be able to play the violin, after surgery and the doctor says of course only to have the patient say, that is funny because I could not play it without the surgery. So since they were headed down a medicated path and are now on unmedicated one, they are happy as long as their numbers do not creep back up. I am not sure if that does or does not happen. Some people mention it happens but I do not know how strict they are being. Most have accepted that they will not be having crumb cake anytime soon or possibly ever.

[quote=“Fry, post:30, topic:23257”]
I have seen studies that show the insulin sensitivity improvement is temporary.
[/quote] I would be curious to see the studies that prove this

If someone is healthy, insulin sensitive who has a few pounds to lose but is not prediabetic, then I might do my own research


The author of the page I put up is Mark Sisson and I don’t know anything about the blog fellow. Mark Sisson and a few other prominent health writers and scientists like Chris Kresser, Peter Attia, Robb Wolf, etc. who have been low carb for a long time, are insulin sensitive, and are particularly fit (resistance training seems to do something really great for metabolism) find that they do best mostly keto, but they cycle in some carbs or some periods of bumping up their carbs a bit. Not a ton, and they’re careful about the quality of the carbs (not pizza and donuts! more like sweet potatoes and squash). I think Attia spent several years strictly keto before he did that and you could check out his blog to read about how/why he started adding in more carbs.

I would read Richard’s post several times and then do some digging around to reassure yourself.

(Jen ) #34

Are you in the US? If you are obese or have metabolic syndrome, you can definitely be referred to a nutritionist by your doctor (covers medical necessity- my past job was getting authorization from insurance companies and out of the hundreds of patients referred to a nutritionist zero were denied). I hope my posts aren’t coming across as hostile- I’m just trying to help!



Thank you. You make good points, however I will point out that the article in question implies that, while these fasting blood sugar values dropped to 80 or 90, they will creep back up to be over 100 (prediabetic) over time.

As to where I read that the positive health effects are temporary, I have looked and looked but cannot find the study or studies! However I did find one that states it:

"Based on the available literature, KD may be associated with some improvements in some
cardiovascular risk factors, such as obesity, type 2 diabetes and HDL cholesterol levels, but these effects are usually limited in time"

However I remember reading studies that showed exactly this but about insulin sensitivity specifically.


I am in great shape and have normal (not pre or diabetic) numbers so they declined my request to see a nutritionist.

(German Ketonian) #37

I have consistently high BG around 90-110, no matter if I am fasting, eating or the hour(s) after eating. I am getting my HOMA test results, fasting insulin, blood glucose and HBA1c tomorrow… I am excited! I have been dealing with my BG levels for months now, fearing I might be (pre-)diabetic. Since I am lean and healthy, though, I suspect adaptive glucose sparing to be the culprit. But that does not necessarily mean it’s less concerning to me. After all, high BG readings continuously can’t be good for your, right? I understand that my body adapts to keto by providing higher levels of BG in the blood to be “ready for combat”. And since my muscles are in glucose refusal mode, there’s more in the blood stream. But considering my readings around 110 in the morning and after fasting for 48 hours, I am still concerned.



This is exactly what we are discussing and yes it freaks me out as well. According to the author of the article in question and other sources it may be normal and not unhealthy and your ha1c may be normal despite a high fasting blood sugar.

How long have you been doing keto?



Thanks and will do. I am already familiar with Peter Attia and Chris Kresser and will look into the others and read Richards post carefully.

(German Ketonian) #40

Hi @Fry. Have been on the keto diet for 3-4 months now. I am following a VERY strict regimen, hitting a 88% fat ratio, while usually keeping protein limited to 80g max, and 10-15g of carbs. I am 185cm and weigh around 70kg



What were your fasting blood glucose values before you started the diet?