Can you have high blood sugar without carbs? Well, it’s important to look at common beliefs about high blood sugar first.
“High blood sugar is bad. Carbohydrates raise blood sugar. Therefore carbohydrates are bad.” The theory is simple, and yet incredibly flawed.
The truth is, you can have chronically high blood sugar even while religiously avoiding every starch and sugar in sight. Low-carb forums are littered with posts asking a very relevant question:
Why is my blood sugar so high when I’m not eating any carbs?
The answer is simple, yet often overlooked.
Cortisol Raises Blood Sugar via Gluconeogenesis
If the body were an engine, glucose would be its fuel. Most people think glucose only comes from carbohydrates (sugar and starch), but protein can also be turned into glucose when there aren’t enough carbs around to do the job.
This process is called gluconeogenesis. In layman’s terms, gluconeogenesis is the process in which the body breaks down amino acids (proteins) into glucose (blood sugar).
High stress hormones can trigger gluconeogenesis. (source)
So basically:
- Stress (physical, mental, or emotional in origin) triggers the release of stress hormones like cortisol and adrenaline.
- Stress hormones trigger the process of gluconeogenesis.
- Gluconeogenesis causes your glucose levels to rise (high blood sugar).
When you have high cortisol levels (from diet, lifestyle, etc.), the cortisol rapidly breaks down protein into glucose, which can raise blood sugar levels considerably. For some folks, this results in chronically high blood sugar–even if they are on a low-carb diet.
Cortisol not only breaks down protein from what you eat… it also cannibalizes amino acids already present in your body. Where are these amino acids from? Well, they can come from lean tissue in your body – including muscle, bone, and organ tissue.
Cortisol Side Effects…
High blood sugar and lean tissue loss aren’t the only side effects of high cortisol. When your stress hormones are high, you can also experience:
- Acne
- Panic attacks
- Weight gain
- Fatigue
- Irritability
- Hair loss
- Insomnia
- Lower back pain
- Allergies
- Impotence
- Low sex drive
- Poor memory
- High blood pressure
- Arthritis
- Gut flora imbalance
- Fibromyalgia
- Irritable bowel syndrome
- Suppressed immunity
- Asthma
- Accelerated aging
- Headaches
- Depression
- and more…
Doesn’t look too fun, does it?
So before you blame carbs for your high blood sugar woes, consider that high cortisol may be the underlying problem. And addressing the root issue (high cortisol levels) can have a pleasant domino effect by preventing or eliminating the issues above as well.
I talk a lot about stress hormones in my book, The Nourished Metabolism.
How are your stress levels, cortisol levels, and blood sugar levels? Tell me about yourself in the comments below!
The final sentence says ‘addressing the root issue’ but doesn’t explain how to do that. Reduce stress, therefore reducing cortisol?
Great question, Kelly. Reducing stress is obviously the key, but that’s a multifaceted subject to say the least! I will be doing more posts related to this in the future.
For now, I added some links at the bottom of this post that will take you to some other articles I’ve written relating to stress and cortisol.
Hi. Type 2 for a few years. I had a bad few months of eating and stress and just can’t seem to get my numbers down. 200-300. I’m watching my diet ( not overweight) but am frustrated. I take metfirmin as prescribed. It’s been two weeks since I have really tried to get things back to normal ?
I can’t give medical advice, but I would talk to your healthcare provider about ways to reduce stress or better cope with it so you can lessen the negative impact it has on your body. Meditation, walks outside, or simply have a supportive friend to talk with could help.
Try a ketogenic diet
Worked for my t2 I stopped taking meds
I stopped taking all my meds a week ago. I went through three days of pure agony. It’s been one week today that I stopped everything, including my psychological drugs. I feel better now than I have felt in ten years or more. I had a very bad psychotic episode back then. Anyway, long story short, I changed my diet to protein and vegetables only but my blood sugar will not stay below 150. Like I said, I feel great but my Doctor (PA) says I should be no more than 100. I don’t know what else I can do. Any ideas. By the way, before these changes I was anywhere from 200 to 500.
Hi Kelly
My Dr put me on Adrenal support supplements to diffuse high cortisol levels.
Hope this helps You
Thank you.
Excellent information (again) bringing to light that although diet is foundational, it’s not all that matters! Well done Elizabeth!
Thanks, glad you enjoyed it!
But if you would need to classify people by their cause of high blood sugar wouldn’t be almost everyone because of too much wheat/starch/sugar and a small % due to gluconeogenesis?
I would honestly say just the opposite. High cortisol levels are extremely common and influence blood sugar beyond just gluconeogenesis (by causing inflammation, etc.).
Now, eating a diet heavy in starches when your gut health is compromised or eating carbohydrates exclusively to the point of causing nutrient deficiencies will most certainly raise cortisol levels, so there are definitely different levels of cause and effect going on here.
However, eating carbohydrates can *lower* stress hormones, too, so there are a lot of factors to consider.
Actually cortisol has anti-inflammatory properties.
In the short-term, yes, which is why it’s so useful in urgent situations. However, because of how cortisol effects other systems in the body, in the long term it promotes inflammation and autoimmunity conditions.
Sorry, I’m just having a hard time buying any of this. I was on two different diabetes medicines and still had a sustained A1C of over 17. I switch to strictly controlling Carb intake and I’ve kept my A1C to 5.3 for months. In fact It’s been at 5.5 or less for two years. I’m down to just 1000 MG of Metformin a day. Losing weight was another benefit of dropping the bulk of my daily carb intake and replacing it with healthy fats and protein. I’ll add that the improvement in glucose management came within 3 months or less. Well before the bulk of the weight loss. Maybe your advice is better fitted to people who don’t already have a compromised metabolism like T2 diabetics.
I agree, when you have a condition like T2 diabetes, it does complicate the matter even more. This article about stress and diabetes is really interesting: http://www.diabetes.org/living-with-diabetes/complications/mental-health/stress.html
“Stress hormones that are designed to deal with short-term danger stay turned on for a long time. As a result, long-term stress can cause long-term high blood glucose levels.”
I disagree. My A1C was controlled prior to a low carb ketosis diet. Now my blood sugars are more than double what they were when I was eating carbs
mine too and i cant understand why???
I have just experienced raised blood sugars while on keto as well. Super frustrating
What you describe happens in a Low carb, Low fat, HIGH protein diet. You are grossly misinformed on the metabolic results of todays low carb, HIGH FAT, moderate protein diet. My native elders had a name for the high protein diet and the illness it caused “Rabbit fever”. Today we call it the “Faileo diet”. It never works.
As far as cortisol, its a bit about context, you need some gluconeogenisis when doing high fat, low carb, but not nearly as much as when you do high protein, low fat, low carb, again which is the diet you are describing when you bring up the issues above.
As well the cortisol increases over 24 hours are barely a blip in a high fat diet, in orther words a low fat high carb diet and a low carb high fat diet release fairly similar amounts of cortisol over 24 hours, but this is rarely tested relying instead of morning measurements which inheritently favor high carb diets.
I suggest you do a bit more research before you lump both versions of low carb together. The diet you are describing is “low carb basics” to us practitioners. High protien, above 35% of calories, is toxic. Protein should never be ingested to the point where it must be used as the primary energy source. That is why when you drop carbs YOU RAISE FAT.
Not sure why I bothered to write this on the 100000000th blog who got it wrong now but what the heck, its been a slow day.
Hi Danny, thanks for commenting. I hope I can clarify what I meant.
As you said, gluconeogenesis is possible even when dietary protein is low. This happens as a direct result of high cortisol, which breaks down protein from lean tissue mass (in muscle, bone and organs). Cortisol does not require protein to be in the diet to perform this function. It takes it directly from the body itself.
As I’m sure you well know, cortisol levels increase for a variety of reasons, not just due to macronutrient ratios. So due to other factors (lifestyle, toxin exposure, etc.) cortisol levels can be chronically high no matter what your macronutrient ratios look like. And this will lead directly to gluconeogenesis and the breakdown of lean body tissue.
Know this is old, but again……
The body can make glucose from FAT. I lost 50+ lbs on a low carb, moderate protien high fat (my own mostly) diet. I lost only about 3 lbs of lean mass, and based on my weight lifting, i lost no strength, meaning that the proteins that were lost were most likely unneeded collagen/connective tissues in fat and skin.
Yes, my fasting glucose went up a bit (77 to 99) BUT my A1c went DOWN, my post meal glucose went way down and my triglycerides went way, way, way down. My HDL went up. By all meaningful measures low carb has dramatically improved my health.
The body can make a small amount of glucose from fat, but the process isn’t very efficient. The energy we get from fat is typically ketones: https://chrismasterjohnphd.com/2012/01/07/we-really-can-make-glucose-from-fatty/
Thank you Danny. Not everyone is interpreting things badly.
What do you think of this recent post that suggests the following: although cortisol can certainly stimulate gluconeogenesis, it is GLUCAGON that is the primary trigger in the setting of low carbohydrate driven low blood sugar? http://www.ketotic.org/2012/07/ketogenic-diets-and-stress-part-i.html
Interesting post, thanks for sharing it. Glucagon definitely plays a role in blood sugar regulation.
In my post I’m referring to an explanation for the phenomena that a lot of low-carb dieters seem to experience–chronically high or even climbing blood sugar levels even when they ingest few carbohydrates. Cortisol is a viable explanation for this. Whether or not the cortisol is caused by diet ratios depends on the individual. Cortisol can be high for many reasons not directly associated with diet.
There is something to this indeed. Last week my blood sugar never went over 110 – even after eating pizza for lunch it was only 94 2 hours later.
Today I wake up to 161 !!!
Thanks for the great article! I am in a bit of a quandary because I have high cortisol levels that appear (at least from saliva/urinary analysis) to come from persistent bacterial infections. I went low sugar and low carb for six months and took antifungals to kill off candida and other bad bacteria, but my metabolism took a terrible hit- I gained weight and my blood sugar issues showed no improvement. Do you know of a way to kill off bacterial/fungal infections without stressing the body?
Thyroid health is imperative for battling bacterial and fungal infections on a metabolic level. For directly treating the problem, supplementing with small amounts of sublimed sulfur, activated charcoal or simply eating a raw carrot daily can help with these problems.
Thank you for the suggestions! I have never researched sublimed sulfur or charcoal for bacterial/fungal issues. I’m on it right now (-:
The only way to get rid of those bacterial infections is by getting our guts healthy and that is through taking good quality probiotics. I have been a diabetic for 15 yrs and i have experienced so much of the effects of bad bacteria in my body resulting to so much health problems like yeast infection, fibromyalgia, depression, etc…read about it and check out where i get my probiotics from…candidasupport.org. for 3 yrs now i have had relief through this…along with proper diet and exercise, i got my energy back and i’m feeling a lot better!
Elizabeth balance is the primary factor, and balance is strictly per individual .one cannot get where one wants to be without some understanding of where one is, a functional concept of real , and a perception of cause and effect. all of these depend on viable information thank you for providing what you can.
I agree! Balance and the condition of the individual are paramount factors in achieving great health.
I hope you are still following this even though you wrote it almost 2 years ago. I recently started taking a seizure medication that has lowered my appetite quite q bit, yet my blood sugars have been through the roof. This has been frustrating to say the least, especially since I have been cutting out the amount of sugar and junk that I was eating. I figured that my liver was was kicking glycogen into my bloodstream since I haven’t been eating as much due to my medication, but the cortisol really makes sense too, especially since I am prone to panic attacks. Thanks for the great info!
Lowered appetite can definitely be linked to high cortisol levels. A lot of drugs that lower appetite on purpose do so by raising stress hormones adrenaline and cortisol. It’s a continuous cycle, too, because if you aren’t eating enough, that will keep stress hormones high as well.
Hi Elizabeth,
Thank you for this great article, it makes a lot of sense to me.
I started a low carb diet 3 months ago in order to get healthier, loose weight and try to avoid getting type 2 diabetes after having a pregnancy diabetes.
3 months into the diet I got a result of a1c 5.8, higher than ever before on high carb diet. My fasting blood sugar also ranged between 97-105.I was very confuse, thinking that my sugar levels should have dropped on the new diet and not the opposite. Reading about cortisol really made sense.
So whats the best way to lower the sugar levels and avoid high cortisol apart from lowering stress levels? AI have 2 young children 🙂 is it raising the amount of safe carbs?
Thank you
Sorry to rain on your theory, but the real reason peroples blood sugar – boh fasting and postprandial – rise on a low carb diet isdue to insulin resistance from a combination of high fat and low carb. This type of insulin resistance s called physiological insulin resistance and is a mechanism through which the body spares glucose for the brain. It is debated whether it is bad for the body or not; I tend to think it is.
If that’s the case, wouldn’t every Inuit/Eskimo that lives on a traditional high fat low carb diet be insulin resistant?
even though I have fasted or even eating proper my sugar is over the roof….Started off fab 100 to 110 great for a two month period then all of a sudden shot up to 235 to 453….no side effects or anything saying your body is in trouble….So they gave me two different meds metuformin n glipazide……still now out of control…I have very bad back n hip problems n they are saying due to the very bad pain I have it raises my sugar n my pressure…..The pain has gotten so bad that I actually get to point where i lose my breath n get weak in the knees….Please help..Can the pain be throwing my sugar n pressure out of whack n what can I do about it???? HELP PLEASE..
Pain can affect your cortisol levels which can affect your blood sugar levels. Pain management and stress management is crucial for metabolic health. Please work with a health professional to help get your sugar to a healthy level. Also, self-care always helps. Get some sunlight, eat well, drink enough, meditate, etc. if you can.
When I was diagnosed as “Pre-diabetic” my first thought was “You can’t be a little bit pregnant.” So, I started on low carbs, almost no sugar. At first it worked well, and then — well, my fasting BGL went through the roof. I struggled with it for a while and one day I thought nothing was going to work, so I let myself go and had more carbs and a little more sugar. The next morning I was almost afraid to take my BGL, but it was down! I tried the next several days on the same diet, more carbs and a little more sugar. My BGL is lower than it’s been in ages, and I’m a much happier camper!
There’s definitely a balance to it! There are so many factors that come into play in terms of how many carbohydrates each of us needs to function at our best. It’s lower for some and higher for others. It’s so good to listen to your body and find what works for you.
I have been experiencing the same thing. I am amazed that after following ketogenic lifestyle, my fasting bg was very high. After starting to add back starchy carbs, only around 75 to 100g daily A.M. readings are lower. My husband is the opposite.
This is a useless and frustrating article. You mention at the end that we need to lower cortisol to remedy the situation, and then you don’t even explain how to do it. You mentioned writing more posts later, but where are they?
All you do is mention an e-book we need to get. So basically the entire post was a sales pitch to buy your e-book. Very helpful.
As I was getting to the end of the article I thought you were going to help me, but now I would never buy anything you’ve written. Shameful.
Hi Adam, thanks for your feedback. I actually have written a post about reducing stress hormones here: https://livingthenourishedlife.com/how-to-reduce-stress-hormones/
I have been a smoldering diabetic for years. What happens when carbs are removed abruptly from the diet is a backlash from your liver. The liver is accustomed to a certain level of blood sugar, and if that drops, especially rapidly, the liver will dump sugar into your blood. This explains why, after I have been low carb and then eat carbs I feel better AND my blood sugars are LOWER. I suggest gradually reducing carbs and I definately am a proponent of fat.
For people that are adapted to burn fat for energy, fasting blood glucose can be in the pre-diabetic range, that can happen because the muscles are saying “no” to glucose (since they prefer fat now) so it lingers around in the blood. In these cases the patient has a low fasting insulin level and a high insulin sensitivity.
So measure glucose levels + insulin and do the HOMA-IR calculation taking any conclusions.
Hi Elizabeth,
I have a question, you state a lot of opinions about lo carb and cortisol being the culprit. You even go on to claim your body self canbolizes itself. Could you post your references for the studies that you obtained this information?
Definitely. Here’s some research on how cortisol can increase gluconeogenesis: https://www.ncbi.nlm.nih.gov/pubmed/11724664 and an article that goes into greater detail about how muscle tissue can be metabolized here: https://www.sciencedirect.com/science/article/pii/S152586101630113X. And also research that shows that low-carb diets can increase cortisol levels: https://jamanetwork.com/journals/jama/fullarticle/1199154
Obviously, each one of us is different when you put together all the factors like genetics, lifestyle, stress, diet, exercise, etc. So it’s helpful to take into account these differences and also pay attention to how your individual body responds (in how you feel as well as biological indicators like body temperature, blood sugar levels, and hormone testing, etc.).
Look up Youtube videos on biochemistry and cellular respiration. Or take a class. It is not opinion. People got Nobel prizes for discovering each excruciating detail. Pick up a book. You can get a used biochemistry book for fair price used and not the newest.
I am so frustrated. I am one of those who doesn’t eat processed foods, white flour and sugar products, grains, beans, root vegetables, soda, or anything other than water, tea and coffee, and my sugar came back over 300. My doctor is frantic and wants to put me on metformin. He is very concerned about the potential for a stroke. I have no symptoms, take cinnamon, ACV, berberine, and other blood sugar supplements, drink a ridiculous amount of water. and really do not want to take the meds. I actually think my blood sugar is coming down…but because this is his first time seeing the readings, he naturally assumes that it is high. I do not have anyone to discuss this with, that is why I was thrilled to read your article on cortisol, and sign up for more information. I am anxious to find out more about controlling my cortisol levels. I will probably take a very low dose, just to appease him, but begin moving, lose weight, and as my numbers come down, just get off of it altogether., I would love to hear your thoughts…God bless you for your help…
I definitely think working with your doctor to continue monitoring your blood sugar levels and how they’re affected by lifestyle/diet/medication, etc. Physical activity does play a big role in both blood sugar and cortisol levels.
I have Cushing’s disease and am the first person in the U.S. diagnosed with “cyclic” Cushing’s in 1989 in Seattle. I have had 2 brain surgeries for a pituitary tumor, one in 1989 and 2nd one in 2016; the tumor is growing and may possibly need a 3rd brain surgery. For the last 3 years I’ve been dealing with high blood sugar, with my last reading 8.4…I’ve changed how I eat and lowered my carb intake and cut out all sugar drinks. I’m not on a keto diet as I have no gall bladder. You statement of how the Cortisol level can make the blood sugar high. My ACTH level is high and the tumor is secreating the ACTH..
how do I balance the glucose to get the 8.4 down? I’m taking 2 diabetic meds I started them 2 weeks ago, with my blood sugar 180 this morning I’m beginning to think that I’m beating my head against a wall as the hormone imbalance is so messed up there is no way to regulate the blood sugar, even with the diabetic meds. What is your thoughts on this?
Your situation is definitely complex, and I can’t give any real recommendations considering all the factors. I would work with your doctor on a multi-level approach to help with your blood sugar levels. Things like meditation and exercise may play a big role for you. I hope you find some answers. Hugs!
I don’t have a gallbladder or a thyroid gland, am post menopausal, type 2 diabetic, and have been doing KETO for years. My a1c is 5.3, and I’m not on any diabetic medication and never have been. I was a dialysis nurse years ago, so I’m very motivated when it comes to diet.
Your body will not use its own muscle tissue as fuel if glucose is in short supply, this is a myth. Our bodies are not stupid. Why would you burn your sofa while you have all this clean, sustainable wood? (Fat stores) If this was true, the human race would most definitely be extinct. NO, our body when it enters ketosis releases hormones that PROTECT our muscle tissue.
You might enjoy reading this article (which, incidentally, is actually pro low-carb): https://www.dietdoctor.com/low-carb/fasting-blood-glucose-higher
Quote:
** “Prolonged cortisol stimulation will raise blood glucose levels,” notes Dr. Jason Fung, who wrote an entire chapter on the stress hormone in his 2016 bestseller The Obesity Code. In it he describes how cortisol, released from the adrenal glands, sends a message to the body to release glucose to prepare for a perceived threat, spurring gluconeogenesis in the liver. In prehistoric times, that surge of glucose energy was usually used up fighting or fleeing from the threat. But in current days, often that stress goes unreleased, the energy not used, which can lead to prolonged higher glucose levels (and higher insulin levels to try to bring it down.) **
Been a type 2 diabetic for 15 years at least and some symptoms may go back even further. People should realize with type 2 that not everything is out of balance with your body. Typically your insulin is being produced its just not working correctly. The best fix for type 2 diabetics is a dramatic and consistent change to a much less carb oriented diet and a focus on proteins and good fats. If you rely on drugs alone they only mask or try and slow or expel the carbs taken in they do not repair the insulin resistance. All you can do is try and eat better in a way that reduces the demands on your weakened body to process glucose. This means making a permanent change to your diet that creates much less spikes in blood glucose releases. No exact science with this, because every type 2 diabetic is at different stages of the disease. Let’s be clear, no drug cures or heals diabetics. They all try and trick the body into being more efficient in dealing with carbs. But the bodies abilities are still compromised so the best help is to not over tax that weakened system in the first place.