When is high blood sugar and sat fat ok?


I’m new and I’m reading all I find, but there’s so much, I’d be reassured if people like you in this forum, so well informed, would send me in the right direction about something that’s confusing me.

High blood sugar (BS) is the bad thing, more so than what they claim about sat fat (SF). Ok. But then I read about high blood sugar in ketoers due to being fat adapted and the body not wanting to use sugar as fuel anymore.

I understood that it’d be ok, because even though BS is high, insulin is low. But I had understood the molecules of sugar in the blood cause harm and that harm can lead to all the things diabetes causes, like neuropathy, atherosclerosis, etc. Even if the person only has mildly high BS, say 100mg/dL.

The end result in my mind is
Blood sugar is bad
Keto ultimately will make your blood sugar high
Keto is therefore bad because keeps insulin low, but doesn’t solve the BS problem.

Please, could you help me, or anyone help me understand why blood sugar being high while we’re in ketosis is ok? By being ok I mean not going to cause all the bad things high blood sugar is known to cause. I know you all must see it as obvious, but I couldn’t find an answer to this question yet. Please, help me understand.

I’m trying to be sure keto is the way for someone who has no weight to lose, only is seeking better health.

Another question, is high blood sugar ok only if we’re in ketosis, or is it enough to be in low carb (say less than 75 g net carbs, for instance)?

My other question is about sat fat. I’ve just read the book The XX brain and the author, dr Lisa Mosconi, a researcher about Alzheimer’s, says sat fat is bad. I had already accepted it wasn’t, but her book is pretty recent. I was thinking, perhaps sat fat is only good for men. The book is about women and the problems lack of estrogen cause, like it’s effect on incidence of plaques in the brain. Men, by having testosterone till much later on life than women have estrogen, would have an advantage.

I know I’m a complete noob. I’m just asking for help to understand. Please.

Thank you!

(Michael - When reality fails to meet expectations, the problem is not reality.) #2

Keto results in normalization of metabolism. It does not lead to high blood sugar. When you are in ketosis long term, gluconeogenesis synthesizes only enough glucose to meet the minimal requirements of those few cells without mitochondria to utilize ketones and fatty acids. Any glucose ‘saving’ by other cells simply reduces the amount of glucose synthesized. Many folks on this forum have healed themselves of T2D, prediabetes and insulin resistance by eating keto. You get ‘high blood sugar’ by eating more than minimal, incidental carbs and having an unhealthy metabolism. You may find this of interest:


Thank you, I’ve visited your thread already. But you’re only one person. Here and in podcasts and books there are examples and mentioning of people who get high BS when in ketosis.

I’ve been measuring mine and I get up to 105 mg/dL after fasting for about 20h. I don’t suffer from diabetes. I haven’t even been diagnosed as prediabetic yet (officially by my doctor, even though I seriously suspect I’m already suffering from insulin resistance).

Please, don’t think I think it is bad, I just want to understand the science. I’m sure there’s an explanation and I’m just ignorant and haven’t found it yet.

The explanation/science I’m looking for is: why is it ok to have high BS (dawn phenomenon, wtc) when in ketosis? What makes that sugar molecules don’t hurt our body IF we’re in ketosis? I just would like to understand why it’s ok, to put my mind at ease.

Then, the other question: is saturated fat ok for men, but not to women, or is it ok for women, too, to consume sat fat? The reason I’m asking is because an Alzheimer’s specialist with over 100 papers published says it. I don’t understand the science, what the lack of estrogen would mean. If it changes something.

I love cheese and I need to know if I can continue to consume it, or if it can give me cancer, or Alzheimer’s, since I don’t produce estrogen as I used to (menopause).

Could you point me in the good direction of a paper, or book, or podcast where someone explains it?

Alzheimers and dementia affect women more than men. Why?

So many questions!

Thank you!


You realize even by standard of care that’s considered pretty normal right? Functionally the range is a little different/lower. But even if you averaged that ALL THE TIME which you’re most likely not that would be an A1C of around 5.1 which is very acceptable by any standard.

Ummmm, no? Never seen anybody blame high sugars on keto, not even sure how that’s possible seeing as we don’t eat the stuff that raises it. Dawn Phenomenon is mostly cortisol driven which is a different thing all together.

Keto doesn’t raise my IQ level either, doesn’t mean there’s anything wrong with it, nor does it mean it’s not a very healthy way to eat. I think you’re forcefully connecting dots that shouldn’t be connected.

What did your blood sugar levels look like before keto? How many times a day are you checking and when? What’s a day of eating look like to you? Are you over weight (for your body, not preference) or physically active? Those things have a much bigger effect on things than most people give credit for. Keto can be magic like, but it’s still not magic.

HIGH blood sugar is never really OK, but what you’ve talked about above ~100, really isn’t high. 75g net is pretty high. I’m usually around 50-60g and can pull off being in ketosis for most of the day (usually) but now with the gyms closed not so much so I’m around 30-40g most days. If a huge chunk of the actual carbs were fiber or something you MAY be ok, but only testing will tell you.

(Michael - When reality fails to meet expectations, the problem is not reality.) #5

Yes I am. However, if you search this forum you will soon find many successful accounts of folks who normalized their metabolisms, got glucose and insulin under control and back to normal, reversed T2D and eliminated medications, lost weight and improved their health overall. All they did was eat a ketogenic dietary regimen.

To learn about the science, you can start here. While Virta offers payfor services, their blog and website provide lots of information, case studies and endorsements, and scientific citations to back up what they do. You don’t have to purchase anything to learn. Dr. Stephen Phinney is one of the leaders of ketogenic eating for health and well-being.

(Michael - When reality fails to meet expectations, the problem is not reality.) #6

Also, check out Amy Berger’s blog posts about blood glucose and insulin. The series starts here and each entry links to the next at the bottom. She started this series in Sept, 2015, and posted the last entry in Mar, 2019 ( so far):

PS: This is a deep dive.

(Bunny) #7

I am curious; what are your blood sugars?

You would probably get a better answer to your question?


After you eat?

Before you eat?

Plaque in the brain comes from excessive sugar not saturated fat, it is when you mix the two together and eat them at the same time, with more sugar on top of the saturated fat and has little to do with getting Alzheimer’s, lots of people have severe amyloid plaque build-up in the brain (which is normal) and do not have Alzheimer’s, after reading lots of research it seems like bacteria or viruses get trapped in that amyloid plaque when the blood brain barrier becomes thinner as you age and making the brain burn ketones seems to clear it up somewhat supposedly by using substances like MCT oils or BHB’s for those that are not really ketogenically fat adapted.

I personally think it’s the acetone (one of three ketone bodies that cleans up the brain and the actual substance that cleans it out) which is the lesser produced ketone that really does the work? Only the brain can use acetone for fuel, no other part of the body can use it. If acetone can remove nail polish, it most certainly can remove amyloid plaques with trapped viruses and bacteria?

On a deeper note when the ketogenic diet was originally used on pharmacological resistant epilepsy, the main reason that particular way of eating was utilized was to increase acetone production (repairs neurological damage; BDNF factors: neurogenesis, neural repair and neuroplasticity) and not the production of the other two ketone bodies.


I didn’t know it was normal. I thought above 99 it was prediabetes range. I’ve never done an A1C and I’m so hoping I’m normal.

When I said keto will make BS higher, it was because I’ve read and heard on podcasts (like of Peter Attia), that if a ketoer does a fasting BS test, it has to eat carbs 3 days prior to test normal. Then I assumed that it means that while being in ketosis, the BS would be higher. I’ve read about so many who cut carbs to control diabetes and that’s the main reason I was drawn to keto. I want to cure my insulin resistance. But then, reading/hearing stuff like at the beginning of this paragraph, I was wondering. Because my BS is never very high. After a high carb meal, like lots of sweet cake and cookies, it’d be below 140 mg/dL after 2h. I think that’s considered normal, though I’m not sure, for somebody who doesn’t have diabetes. But I’ve read about insulin and that it may be “normal”, but at the cost of having a lot of insulin thrown in the system to keep the BS “low”. When I keep to my normal <20g net carbs/day, I never test above 110. But sometimes I get an odd day, or two, above 100. It freaks me out. I was hoping I wouldn’t have these while in ketosis. I think I’m in ketosis, because I test (ketostix).

Mind you, I’m not eating sweet things! It was a test! After reading about high BS.

I don’t know much about my BS before keto. I didn’t have a meter. My last fasting BS at the hospital was 102 mg/dL. I’m afraid I’m prediabetic. I can’t see my doctor, because of the coronavirus situation in my country. But I started keto and my hope was to never see something above 100 again.

My food is like: lots of cheese (0 carb hard cheese), broccoli/cauliflower/celery/spinach counting carbs, salmon, chicken, pecan nuts (counting carbs), peanut butter (seriously counting carbs), chia, flaxseeds. I exercise 2h everyday. My BMI is 22.5. I’ve never been obese and have only been slightly overweight twice in my life, a long time ago, for only a few days. I’ve always exercised a lot.

The question about 75g carbs is because I’ve been reading about dementia and other problems postmenopausal women are prone to and I think I need to eat more greens to get more nutrients and anti oxydants. But if I do, I’ll probably go over 20g of carb and I’m trying to find out if it’s safe and how low I could go. I wonder, for isntance, if I need to be in ketosis or if being lowcarb would be enough.

Thank you for you reply!


Thank you for your reply.

My BS is like:
overal average of last 30 days it’s 101 mg/dL.
Average only fasting BS 30 days: 96.
Average 30 days after meal BS: 106. This one is high, because I’ve did several BS tests while testing with very high carb. I wanted to know if I’m insulin resistant. I also test right after meal, 1h later, 2h later… in general. To know what foods affect my BS.

I’m very interested in what you say about Alzheimer’s. But this doctor, who’s a serious researcher, the writer of The XX Brain, she says a Mediterranean diet (whatever that is, because they never give details of what it is!) is the best for women (specifically women). She says to avoid sat fat. I was so frustrated when I read it yesterday, that I started this thread, worried about it. I’m so into cheese!

What you say about epilepsy is amazing! Indeed, I’ve read the book of Dr Fung and he said about keto being used for children with epilepsy. It makes sense it’d be good for the brain, not bad. And yet, the other doctor, dr Lisa Mosconi, it’s pro Mediterranean diet and against sat fat.

It’s this confusion that worries me so much. I’m afraid to do something against my insulin resistance and end up with Alzheimer’s. I’m already convinced sat fat isn’t bad for the heart. The brain was a new worry, upon listening to dr mosconi on podcast and then reading her book.

I’d love if someone smart, with the science in his mind, would discuss with her and they could get a consensus. For the rest of us.

I’ve read a long time ago about the bacteria in our mouths, the one causing gums issues (sorry, I don’t know the work in English) making a kind of fat and that fat being found in plaque (atheroma). It could be also in the plaque in the brain. I wonder.

I’d like to ask you something. You say mixing sat fat and sugar is the bad thing. You talk about eating them together. Say, if I wanted to go not keto, but stay lowcarb, because I want to eat more veggies and some fruits, like berries, not cakes and cookies! But I love my cheese. If I eat them separatedly, does it make any difference? How separated? Morning and evening? Different days? Now, I eat cheese in my 2 meals/day. I eat 2 meals, or 1, every day.

Thank you very much for your help!


Thank you. Some of the Virta stuff I’m already reading. I’ll check also the tuinutrition link. Thank you!

What frustrates me in some of it all, is that it’s like women and men are the same. We are different. I’m trying to find stuff coming from research done with women. When they start saying that the intervention was on 100 obese men… I’m not obese, never was, I’m not a man, never was. But on some days I have over 100 hot flushes, something I think no man has. You see my problem? I’m different from a guy who doesn’t have these issues. I want to know what is good for me. It’s the kind of thing I’m looking for. Research done with menopausal women who suffer a lot with it, who can’t sleep well, because they wake up 10 x every night with the bed soaked in sweat.

Right now, I’m a bit better, but I have periods like this, I’m not exaggerating. What science can help me?


That’s because we sensitize to it. Which is kinda good, kinda bad. If a heavy coffee drinker goes from 10cups a day, to 3 for months then drinks 10 again, they’re going to be bouncing off the walls. Doesn’t mean being able to drink 10 cups of coffee is a GOOD thing, just a tolerance. From what you’ve said I doubt you’re pre-diabetic or even near it. You can grab a do it yourself A1C test at CVS or Walgreens or just go to a lab and get one done, you don’t need a Doc for that they’re cheap enough but the DIY kit gives you 2 tests for like $40 I think. But I really wouldn’t over think it.

(Bacon is a many-splendoured thing) #12

“High” is a relative term. The measurement depends on where you are located, but in the U.S., a serum glucose reading over 100 is truly high, and approaching a level that causes damage. The insulin response to that level of serum glucose also causes its own damage, so the point of a ketogenic diet is to lower insulin by lowering serum glucose.

You appear to be thinking of what is known as “physiological insulin resistance,” another term for which is “adaptative glucose sparing.” In essence, this is something that happens after one becomes fat-adapted (which can take six to eight weeks—or even longer—of eating a ketogenic diet). At this point, the muscles are adapted to metabolising faty acids in place of glucose, and so they resist taking in glucose, thus sparing it for those organs in the body that cannot do without it. This is very different from the type of insulin resistance that develops when the muscles are already awash in more glucose than they can handle.

In physiological insulin resistance, people often see a rise from usual levels in the seventies to levels in perhaps the high eighties. They often get alarmed, but as long as their HbA1C level remains safely low, there is nothing to 2be concerned about. As long as we eat a low-carbohydrate, ketogenic diet, our body will regulate our serum glucose to a safe and healthy level.

Bear in mind also that the serum glucose level can fluctuate quite a bit, and that is perfectly normal. These fluctuations are generally within a fairly restricted range, once we have been eating ketogenically for long enough.

You might be interested in this post from the Hyperlipid blog, which goes into a bit more detail.


Thank you.

I don’t know if we can get these tests here, but I’ll call a pharmacy to check. Thank you!


Thank you!

I think that’s it. Physiological insulin resistance! If it means from 70 to 80s, ok. But what I understood is that it’d be above 100. Edit: I’ve followed your link and I’ve seen I had misunderstood! He was talking about the test where the subject drinks lots of sugar before the test! It wasn’t a fasting BG test, then! Thank you! I get it, now! In my defense, English is my 4th language and I miss stuff when it’s in English. Thank you!

You’ve answered to my questions about BS and I’d like to thank you again, all who helped!

What about the sat fat question? I understood that sat fat isn’t bad for CVD and all cause mortality. But what about things of the brain, like dementia? Is there a nuance about sat fat? I understood that eating lots of carbs and lots of sat fat is a horrible idea. What I’m asking is if there’s a sweet spot of carb/sat fat combination.

Because all the research concluding sat fat is ok wasn’t done with subjects who were doing keto WOE. So, sat fat is always ok? I’m not talking about putting on weight. But if the person is maintaining weight, therefore not eating carbs enough to increase weight, would that mean that this person WOE is ok?

I understood that people like me, who aren’t overweight and who exercise, can still have a fatty liver. How can I be sure my WOE won’t get me a fatty liver? That’s what I’m trying to figure out with these questions. Limit carbs and eat sat fat. Ok. I’m asking: is sat fat ever bad for the brain? Or the problem is always carbs? If BS doesn’t go above 100mg/dL after a meal, does it mean the meal was ok? Ok in the sense that it won’t cause stuff like fatty liver and dementia? Is there a way to know it?

If there is, I’m thinking of testing what amount of veggies I can eat while keeping my BS below 100.

You all have already given me great info and I’m daring to plead for a little more. I thank you very much for your time and patience! Sorry for my stupid questions. I know that’s all super obvious for you.