When your “normal” blood sugar isn’t normal (Part 1)


In the next two articles we’re going to discuss the concept of “normal” blood sugar. I say concept and put normal in quotation marks because what passes for normal in mainstream medicine turns out to be anything but normal if optimal health and function are what you’re interested in.

Here’s the thing. We’ve confused normal with common. Just because something is common, doesn’t mean it’s normal. It’s now becoming common for kids to be overweight and diabetic because they eat nothing but refined flour, high-fructose corn syrup and industrial seed oils. Yet I don’t think anyone (even the ADA) would argue that being fat and metabolically deranged is even remotely close to normal for kids. Or adults, for that matter.

In the same way, the guidelines the so-called authorities like the ADA have set for normal blood sugar may be common, but they’re certainly not normal. Unless you think it’s normal for people to develop diabetic complications like neuropathy, retinopathy and cardiovascular disease as they age, and spend the last several years of their lives in hospitals or assisted living facilities. Common, but not normal.

In this article I’m going to introduce the three markers we use to measure blood sugar, and tell you what the conventional model thinks is normal for those markers. In the next article, I’m going to show you what the research says is normal for healthy people. And I’m also going to show you that so-called normal blood sugar, as dictated by the ADA, can double your risk of heart disease and lead to all kinds of complications down the road.

The 3 ways blood sugar is measured

Fasting blood glucose

This is still the most common marker used in clinical settings, and is often the only one that gets tested. The fasting blood glucose (FBG) test measures the concentration of glucose in the blood after an 8-12 hour fast. It only tells us how blood sugar behaves in a fasting state. It tells us very little about how your blood sugar responds to the food you eat.

Up until 1998, the ADA defined FBG levels above 140 mg/dL as diabetic. In 1998, in a temporary moment of near-sanity, they lowered it to 126 mg/dL. (Forgive me for being skeptical about their motivations; normally when these targets are lowered, it’s to sell more drugs – not make people healthier.) They also set the upward limit of normal blood sugar at 99 mg/dL. Anything above that – but below 126 mg/dL – is considered “pre-diabetic”, or “impaired glucose tolerance” (IGT).

Oral glucose tolerance test (OGTT)

The OGTT measures first and second stage insulin response to glucose. Here’s how it works. You fast and then you’re given 75 grams of glucose dissolved in water. Then they test your blood sugar one and two hours after. If your blood sugar is >140 mg/dL two hours later, you have pre-diabetes. If it’s >199 mg/dL two hours later, you’ve got full-blown diabetes.

Keep in mind these are completely arbitrary numbers. If your result is 139 mg/dL – just one point below the pre-diabetic cut-off – you’ll be considered “normal”. Of course this is perfectly absurd. Diabetes isn’t like catching a cold. You don’t just wake up one day and say, “I’m not feeling so well. I think I got a bad case of diabetes yesterday.” Diabetes, like all disease, is a process. It goes something like this:

malfunction > disease process > symptoms

Before your blood sugar was 139, it was 135. Before it was 135, it was 130. Etcetera. Would you agree that it’s wise to intervene as early as possible in that progression toward diabetic blood sugar levels, in order to prevent it from happening in the first place? Well, the ADA does not agree. They prefer to wait until you’re almost beyond the point of no return to suggest there’s any problem whatsoever.

[End rant]

The other problem with the OGTT is that it’s completely artificial. I don’t know anyone who drinks a pure solution of 75 grams of glucose. A 32-oz Big Gulp from 7-11 has 96 grams of sugar, but 55% of that is fructose, which produces a different effect on blood sugar. The OGTT can be a brutal test for someone with impaired glucose tolerance, producing intense blood sugar swings far greater than what one would experience from eating carbohydrates.

Hemoglobin A1c

Hemoglobin A1c, or A1c for short, has become more popular amongst practitioners in the past decade. It’s used to measure blood glucose in large population-based studies because it’s significantly cheaper than the OGTT test.

A1c measures how much glucose becomes permanently bonded (glycated) to hemoglobin in red blood cells. In layperson’s terms, this test is a rough measure of average blood sugar over the previous three months. The higher your blood sugar has been over the past three months, the more likely it is that glucose (sugar) is permanently bonded to hemoglobin.

The problem with the A1c test is that any condition that changes hemoglobin levels will skew the results. Anemia is one such condition, and sub-clinical anemia is incredibly common. I’d say 30-40% of my patients have borderline low hemoglobin levels. If hemoglobin is low, then there’s less of it around to become bonded to glucose. This will cause an artificially low A1c level and won’t be an accurate representation of your average blood sugar over the past three months.

Likewise, dehydration can increase hemoglobin levels and create falsely high A1c results.

The “normal” range for A1c for most labs is between 4% and 6%. (A1c is expressed in percentage terms because it’s measuring the percentage of hemoglobin that is bonded to sugar.) Most often I see 5.7% as the cutoff used.

In the next article we’ll put these “normal” levels under the microscope and see how they hold up.

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Comments Join the Conversation

  1. Lee says

    Someone I know insists he has a blood sugar level of 615. Yet he doesn’t do anything about it. He functions normally. Is this possible? He says coma comes at 620. I think he is full of hot air. Can someone give me the truth.

  2. Kayla Shore says

    Hello everyone,

    I was wondering if someone could help me. I was diagnosed on Tuesday with type 2 diabetes. Today I decided to look at my blood and urine test results. According to my results and the WHO and Canadian diabetes association I don’t think I have type 2 diabetes, I think I am pre-diabetic. I want to know if I am at any disadvantage if I keep the diagnosis and don’t bring it up to my doctor? and I want to know if I am right and I am only pre-diabetic. I will list my results below

    July 16th- blood glucose after 12 hour fast = 6.1 ( thats when they called and asked me to do a tolerance test)

    – no protein in urin and no glucose in urin

    July 19th- Blood glucose after 12 hr fast=7.2
    Blood glucose after 2hr and the glucose=11.0
    Ac1 taken on the same day = 5.9%

    I am overweight with a BMI > 40, I think I have PCOS. I have never had any symptoms associated with diabetes ( although I do know many people are asymptomatic)

    I am under the impression that if a fasting blood glucose is in the diabetic range it has to be taken on 2 separate occasions and both need to be in the diabetic range ( for me one occasion was-7.1- and one occasions was not-6.1)

    Also if a doctor just wants to use the glucose tolerance test the result should be above 11.0 and not = 11.0 ( and i think the test should be done twice just to make sure-but this is just my opinion and not one set by WHO or the Canadian Diabetes Association)

    I will still be making significant changes to my life through diet and exercise so the only think that will change is my outlook on life.

    Thanks for your help

    • Veronica says

      Hi Kayla, your fasting blood sugar levels are on the border, but you OGTT is diabetic. A truly normal result would have seen you back down in the 5s or 6s at 2 hrs. So for your benefit make some serious changes to what you eat and you could stop your diabetes progressing further. Your test results are a warning and a wake up call. Good Luck.

      • Kayla Shore says

        Thanks for the Reply! I had started to make changes 2 weeks before my tests and I am continuing with those changes.

        I have been testing my blood sugar before meals and after as well as doing a test every morning after fasting for 10-12 hours. I have not had a reading above 6.6. The only time I was at 6.6 was this afternoon 2 hours after lunch, all I had was a small tortilla for carbs, then we went for a 20 min walk about 15 min after I ate. All my other readings including fasting have been between 4.0-6.0 which is considered normal.

        Does anyone else get totally normal readings at home, but when they drink the glucose have very high readings? Could it be because I normally eat a low carb diet, also they gave me the 100ml glucose drink (not sure if that makes a difference)?

        • Veronica says

          How long have you been low carb, and how low carb have you gone – 50g or less a day? If you’ve been low carb for a long time, then it could affect your ability to cope with a huge glucose hit. However, I’ve been low carb for about 3 yrs and a glucose hit doesn’t affect me at all, but carbs do (work that one out). The fact that you get good results while eating low carb, is probably the result of eating low carb, i.e. doesn’t mean you’re not diabetic. So, I would continue with what you are doing, LC, and try to get the extra weight off and you could well find that your are fine. Use the results as a big wake up call and get your life back on track. Good luck.

  3. Kalie says

    I am a Type 2 And has managed my diabetes by diet control over the last 20 years. Recently, it has spiked significantly. In checking shortly after eating, the readings can be 285 and the other night was over 600. Question: should I be concerned with high spikes 30 minutes after eating of 300, if within another few minutes it starts to drop once I begin to exercise? thank you!

    • Veronica says

      Hi Amber, what had you been eating to cause the spike? If you’re already on a low-carb diet then I would be concerned about those sorts of spikes, you probably need to start on medication. If you are not already low carb and those spikes were the result of eating a high carb meal, then you have your answer – cut the carbs. You do not want to be spiking that high.

  4. Amber Stong says

    Three months ago my A1C was like 6.5. Three months later my A!C is 11.5. Yesterday I was fine and today I am a diabetic. I tested my blood with the kit the gave me, early in the afternoon it was 293, later that day I tested it again and it was 246. I guess I am lucky its going down very slowly. Why would my blood sugar level be pre and then jump to full blown. My doctors were having a hard time with that. Let me know what you think. Thank you.

    • Veronica says

      If your diet has remained much the same and you’re not eating loads of carbs, then it seems highly likely that you may be LADA, in other late onset type 1. It would be sensible to get a urine ketone test kit, test your blood sugar levels 2 hours after a meal and if they are high, test your urine too. If you have ketones then it would be as well to get in touch with your doctor fairly quickly.

  5. Alina says

    My fasting sugar level after 12 hours is 95mg/do. And random sugar level after almost 3 to 4 hours of eating is 116mg/dl. Is this normal ? Am I pre-diabetic?

  6. Lichea says

    I am 44 and have a gluten allergy. I’ve recently lost 25 pounds by eating healthy and exercising, putting my weight at 136 on my 5’3″ frame.
    I’ve been feeling sleepy and headachy in the afternoons and borrowed a glucometer. I ate 2 hours ago and my blood sugar was 88. I ate a sandwich (gluten free bread) and some raisins and 1/4 of an avacado. I also ate one fun sized hershey bar.
    Here’s my question…am I hypoglycemic? is 88 too low? Thank you!

  7. Frank Neill says

    Can anyone please help me. I’ve been trying to get figures for blood sugar distribution in the “normal” (i.e. those without diabetes or pre-diabetes) population. I want to know what percentage of people have average blood sugars in the 51-60 range, the 61-70 range, the 71-80 range, the 81-90 range, the 91-100 range. Ideally, I would like this not just for our “European” cultures, but also for those still following their “re-MacDonalds” eating patterns (eg, people from Japan, maybe even Okinawa). Can anyone help?
    I’d also really love to know what percentage of people have a reading of less than 72 (which my diabetes nurse calls “hypoglycaemic” in any one week.

  8. George says

    Hi Chris,

    I’ve been diabetic for 15 years now and for most of that time I never really took care of myself, I would however have my eyes check annually and no issues there. But about 4 months ago, I just started getting headaches, felling dizzy and as if I wanted to faint. When I went to the hospital, it was because my sugars were at 338. That’s when I decided to make a change, however when I went to the doctor he checked my A1c levels and they were at 12, I’m pretty sure they were that high since I was diagnosed. However, after I made the changes I went back to the doctor 3 months later and lost 25 pounds and my A1c levels are 5.7 and my sugars average 117 over 90 days. I take no medications and am doing this on diet and exercise alone. I have had my eyes check and other than some floaters I have no issues with my eyes. My concerns are that my vision was not blurry once my sugars started dropping but now that they are consistently normal, my vision is blurry, will it take time to set in before my vision is normal again? Also, now if my sugar goes over 150 I start getting headaches, feeling dizzy and faint but it never happened to me for 15 years when my sugar was high, will that also go away? Is my body just getting used to me being on the right track? I’m just concerned if these symptoms will ever go away.

    • Veronica says

      You should get eyes checked that sounds like diabetic retinopothy. I should know I have it.Been a diabetic for 22 years.

  9. Kelsie says

    I recently had two fasting blood draws done last week. The first result for fasting blood sugar was 179 and the second result was 170. My fasting A1C was at 6.0 taking at the same time the 179 result. I’m 24 years old and about 105lbs. Im just concerned and my PCP doesn’t seem to be because my A1C is normal and my hemoglobin levels are “normal”.

  10. Debbie Blackwelder says

    I’m panicked. Can I ask you a question? My 31 year old son had his first seizure Saturday (6-6-15) and we have no clue why. List of possibilities:
    Overheated (we do not think so)
    Prior dehydration issues
    Low blood glucose (82 one hr after lunch)
    My question: my mother was a diabetic and my sons dad is a diabetic. My youngest son suffers from low blood glucose which they say is pré-diabetic. I have been taking his readings since the seizure and they are consistently in the 80’s all the time even after eating. Could it be possible the blackout and seizure was sugar related? We have appointments this week with neurologist, cardiologist, and ENT (he now suffers from a crushed nose after the seizure and fall). Thank you, Debbie

  11. connie says

    My 10 year old daughter came out with A1c of 7.1 and insulin total of 3.37 glucose of 130 fasting . Can somebody tell me if she’s diabetic or pre diabetic. Her doctor said it was normal but I know they are higher than normal. Are children normal ranges different from adults. Please help me I’m lost and worried sick

  12. Barb says

    Hi, I’m new to all this , I’m type2 diabetic 54yrs young.
    My morning blood test was 6.2 ate a good breakfast eggs toms mushrooms and sausage, tea and little milk . Then I feel really lightheaded and really crappy , when I test my blood sugar it is5.6.whenever I go below 6 this happens why?

  13. melissa says

    hi my name is Melissa and I have recently been tested for diabetes, and they told me that my blood was fine. well however I don’t understand cause every morning I take my blood sugar, and it ranges from 83-154 so far, ive been taking it for three days and every morning it higher. is this normal or should I have more tests done.

  14. Rachel Fansler says

    I had my A1c tested 3 months ago and it was 5.6 I was taking Chromium for the past 3 months 800-1000 mg a day, I monitored my blood glucose with a kit. Reading were usually normal. Then the the numbers got low even after meals. I stopped taking the Chromium, Things seemed to normal out a bit. Now though they are dropping from a 115-125 after eating to as low as 80 after sometimes even 20 minutes of moderate exercise.
    Is this normal?

    • poppy says

      A normal blood sugar 80-100 after 2 hours of eating it should not be any more than 140,if it is then you have a issue, after exercising 80 is just fine, if you are worried about you can talk to your health care provider after all I am just a 17 year old diabetic.

  15. Linda hedges says

    I had a fasting blood test done week ago and my doctor told me my blood sugar level is 4.5 and he has advised me to go on low fat diet as he said I could end up with diabetes is that true

    • Lynda says

      Oh my goodness. No. Just the opposite – you need to lower the carbs and increase the fat. The low fat advice is because diabetics tend to have more cardiovascular disease. The evidence now is that inflammation may be the more important factor and it is primarily carbs/sugar drives inflammation. Also, it is important that you take in healthy fats, not the industrial processed stuff. For great info on that go to http://www.dietdoctor.com, click on “Health” and then click on “How to Reverse YourDiabetes Type 2″. I think you’ll find links to other useful sites.

  16. Glendora Paxton says

    Hi, I recently had my labs done and my fasting A1c came back at 6.2 and my Glucose came back at 107. Am I diabetic? Would it be safe to add Gymnema Sylvestre to my daily supplements? My father and his mother were both diabetic and I don’t want to go down that route. Also, I’m a little confused about whether I’m leaning more toward hypoglycemic or diabetes or either! My doctor was not much help, just to say that I was a little high but not too bad. Please help!

    • Sandy hartnett says

      You are wonderfully normal! You are not diabetic! They did lower the glucose level from 125 to 90. But that’s just so everyone can be termed diabetics! Keep up doing what u r doing!

    • dontlistentosandra says

      Don’t listen to Sandra,
      Pre diabetic fasting glucose is 100-125 At 126 fasting glucose is considered diabetic.

      many times drs may order A1C testing but there are things that can impede on those test and give false low or false highs. Things including blood transfusions, anemia and so forth.
      Get your read advise from an MD.

    • says

      The 125 is “Diabetic” is a little weird. Of course this means you see your Doctor every 3 months, labs, dieticians, it all equals money. You can live to 100 with a glucose level of 125. Really 99 and I am pre-diabetic? No, Dr’s + accountants+ low indicator #’s = more money for everyone but you. That doesn’t mean you shouldn’t watch what you eat, its just that your probably doing a lot of “right” things already.

  17. Misty Judson says

    Hi Chris,
    I am a 28 year old female and have no family history of diabetes. However, I am always extremely weak and nauseated in the morning or after any length of time fasting. Over the last two week I have felt my blood sugars fall extremely fast leaving me dizzy,hungry,sick to my stomach, irritable and weak while shaking. I finally decided to go to the doctor because I couldn’t maintain a set point any longer. She said my symptoms would say I am hypoglycemic which has no treatment. She said nothing about me would say diabetes. I asked her to run an A1C at the suggestion of my A&P professor so she did. I had an A1C of 5.5 which she said was perfectly normal and had no indication of diabetes. She also threw into the mix that my hypothyroidism could be the cause of my blood sugar levels. I am at a loss! I would love to hear your thoughts!

    • Annette says

      Christy, I’ve noticed more and more theses days that doctors don’t treat people…they treat test results…when they catch them. Recently, I have discovered Bio-hacking thru a website about adding healthy nutrients to your morning coffee/tea ….it’s called Bullet proof coffee. The site has associated pods casts with a never ending wealth of health and scientific information on how to hack our biology to heal ourselves. It’s a bit of work but I’m already seeing results in two months after being “sick” for years.

      • Sandy hartnett says

        I’ve been doing bulletproof coffee for a month. I’ve lost 12 lbs. without trying. It’s a delicious way to have your coffee. It also gives you more energy! Just tell friends to look up http://www.bulletproofcoffeediet.com. Glad you discovered it and are doing so well! Keep at it! Hugs, Sandy

      • Ed says

        I am 60 years old, overweight and diabetic. I’ve had this disease since I was a teenager. I have gone to the classes and received the certificates. I was a very “educated” diabetic. My disease was bad and getting worse every year. A1c 14.7 fasting blood sugar well over 300.

        What I was to learn is that my diabetes education led me to a path that only worsened the disease. Much of what I “knew” was based on what has proved to be bad science, influence peddling and marketing sleight of hand. It was almost the exact opposite of the path I had now follow: one that is a miracle in my judgement.

        I did a great deal of research to come up with the lifestyle changes I have now implemented. Did they work for me? A1c is down to 6.1 and still falling. Insulin is down from 300units per day of Lantus/Humalog. I have lost 30 pounds and still dropping. Many issues with inflammation and blurry vision gone.

        There is a free documentary on NETFLIX called “Fed Up” that focused on childhood obesity. There many ideas that will frighten you but if they urge you to keep looking for answers, that would be wonderful.

        I would suggest the information at dietdoctor.com is robust and was very helpful to me. It was also free. After i had very successfully put many of the principles I discovered there I practice I joined the community but felt that $9.00 a month was a fair price for changing and likely extending my life.

        Good luck. I hope this information is life changing for you as well.

    • RachelH says

      your blood sugar drops like a stone because you are raising it too high.

      A low carb, high fat or Ketogenic way of eating will prevent that.

      Gluten (a protein in wheat, barley, rye) is worse than sugar for spiking blood sugars. No room for pasta or bread-y things on keto.

  18. Subhash says

    Hi Chris,

    I am an Indian with 48 old (weight 103kg and height 6″feet)and last few years I am monitering my bg regularely. Nw a days my fasting BG is around @110 (100-110) and shoots up to 280-300 after 2 hours of meal( breakfast) and it is purely related to what I eat(amount of carbohydrate). After Luch But it comes back in range (120) after 2 hours(means total after 4hours). What is the cause of it? What action would you suggest ? Please advice

    • Lori says

      Exercise at least 30 min per day. Cut down on soda, chips and other sugary drinks and/or foods. I found exercise is doing the trick for me more then the food and watching the carbs.

  19. says

    Hi I need to know if my readings on the glucose meter are normal or if I should worry and test further . I am not diabetic but don’t ever want to be either .I woke up and did not eat and testes at 88 ate lunch drank juice and water testes two hours later and was at 132 is this normal for non diabetic ? Please help ?

    • Veronica says

      Hi Angela, your reading of 132 @ 2hrs after food is probably absolutely fine, but I does depend on what you ate. If it was a high or moderately high carb meal, then 132 is OKish, if it was a low carb meal then 132 is in the zone to start looking at your diet. Ideally you should be back down to around your start point at 2 hrs. Try testing at 45mins to 1hr after food to see if you are getting high spikes (over 160), if you are then start to look at your diet and make improvements. Remember that its mainly carbs that raise BG levels, high GI will spike you earlier, around 30-45 mins, low GI will spike you later, anything from around 1hr30 to 2hr30. Once you can see if there is a problem, you can work out what it is and make adjustments. Ideally you should remain below 140 all the time, but a brief excursion to 160 will not cause you any damage as long as its not too often or for too long.

  20. sarfraz says

    I am healthy man some times my fasting blood suger come under 100 after 11 or 12 hours when i take sugar food when no sugar food then after 8 hours it comes down 100 while i am healthy man of 58 please give me advice

  21. Danielle says

    Hi Chris,

    So my concern is I have been feeling tired after meals for the past week. I had gestational diabetes with my son born a year ago, but my sugar levels went down right after birth. Now I have been using my accucheck meter to see if this is why I have been so tired. My fasting glucose has been in the range of 109-117 in my left hand over the last 3 days but my 2 hour post meal is 154 from the left hand and 110 from the right. The range is so large. The test strips and machine are all the same. I believe if I checked my fasting on my right hand it would be lower too under the 99 mark. Do you think the other tests will help give me a better idea if I am actually Pre-Diabetic or not?

  22. cathy says

    I’d been having blood test regularly for a lot of years…then suddenly I was told I was diabetic….I couldn’t understand why nobody realized that my blood sugar reading was getting higher…..diabetes doesn’t just happen suddenly…..I had no symptoms….no thirst….no weight loss…..but I was taking statins for years……now …they tell us that statins raise blood sugar and can cause diabetes……I stopped the statins…..my b.s has come down….and my dr. is very pleased with my a1c results….he says they are as good ///if not better than some non diabetics….he’s not pleased that I stopped the statins….

  23. Steven Weix says

    i’m obese and was diagnosed DIABETIC 2 years ago, but drastically reduced my carb intake and brought my fasting bg readings down to 74-84. However, I got lazy and started eating poorly, and gained weight back (i lost about 60 pounds in the dieting process). So fearing the bad news from the dr., i’ve started back onto my good habits and my post prandials (2 hrs) are around 105-115, but my fasting never seems to drop under 90 (though it has stayed under 100)… anyone have any advice or thoughts on this?

  24. Dawn says

    Need advice…I had a 20 hour fast yesterday and after 18 hours my bg was 3.3, I felt awful, however was told this is normal, it keeps happening where I keep feeling low after about 4 or 5 hours of eating. I bought a home monitor and when i was discharged from hospital I was given a sanwhich and some orange juice, went home and tested one hour after eating and it was 11.7 is that normal? Please help this is all new to me. I have done a previous 12 hour fast and my bg was 2.6!

  25. Guillermo says

    My glucose was 230 this morning. I read the comments herein and went for a job at 10am. When I got back my gl was 190. Still high but it showed me the way! Thank you!

  26. Hayli says

    So I feel nervous with what I’ve read. I have recently been getting really sick, dizzy nauseous shaky those things. I went to the dr and they drew my blood and have a blood test thing to me for the next 10 days or so. My first two readings 1 when I had eatin maybe 20 minutes prior was 139 and a few hours later now. I’m feeling sick again and tested at 110… What are some solutions to save myself? I know 139 is bad… I don’t understand though why I feel so sick at 110? I don’t know if I’m asking my question well but I’m very worried and just don’t want to end up with diabities… I’m a 24 5’9 and 170 pounds female who is trying to be smarter with my food choices…
    Any advice or some explanations? Is dropping so fast a bad thing too?

    • natasha hardison says

      I have read many post but yours caught my attention. I am a cna and work with diabetic patients. My mother n law is also a diabetic and I have to keep a close eye on her. Normal levels range from 70-140 you can push it a little as long as it doesn’t go over 200. I have done lots of research on this subject however, everyone is different I have found. One of my patients can have glucose readings that just reads hi then 1 hour later she is bottom out on me. The best advice I can give you is to know your body test yourself before breakfast and an hour later. Eat small portion meals frequently. For example 3 meals a day maybe 3 small snacks. A half a peanut butter sandwhich and 1 cup of juice should help hold your sugar through the night. If you have problems with waking up with low sugar set your alarm at night for 3am drink a cup of juice if to low it does’nt hurt to add a spoon of sugar or eat spoon of jelly to get it up if around 40. It is a proven fact every diabetic sugar drops at 3am. I wouldn’t worry about sugar levels at 139 that is good. My patient would go to bed with sugar levels around 180 and at 1am drop to 70 at 3am to 40. So everyone is different some are more sensitive than others. You shouldn’t be having problems with your sugar being at 110 but that doesn’t mean its not possible.

  27. TIM says

    I have no family history of diabetes, I have always been a big guy, 6ft and 280 lbs. Recently my wife has been testing her blood sugar levels and for fun I decided to do mine. My glucose levels have been from 300 to 600 within the past two days every time we test. I test before meals, after meals, after fasting for 4 hours. we also bought a ac1 test and mine came to 11%. any ideas, am I diabetic?

    • says

      Tim – Those numbers would definitely be classified as diabetes. And 300-600 mg/dL blood sugar is dangerously high. You could potentially have Type 1 diabetes, which is an autoimmune condition that destroys the pancreatic cells that produce insulin. Either way, you need to see a doctor immediately.

  28. veronica says

    Surely if your fasting BG level is low it means that your are not particularly insulin resistant? Virtually everyone that I know that has insulin resistance has a high fasting BG. The fact that you are producing loads of insulin indicates that you are insulin resistant. I have really low fasting BGs, but spike really badly after consuming more than about 20g of carbs simply because I now don’t actually make much insulin and so cannot cope with any more than that small amount of carbs. If you are insulin resistant wouldn’t your BGs stay high because the insulin that you are producing is basically ineffective?

    • Howie says

      Hi Veronica, what I’m trying to say is that I’m severely insulin resistant and confirmed by an NMR LP-IR score of 67 and sky-high fasting insulin level. My functional doc has told me that if my pancreas is still very efficient (so I’m not a diabetic) at churning out the insulin, then it’s able to keep my blood sugar normally low. It means that if there are two cars going the same speed down the highway, one car would be going at 10,000rpm (my pancreas) and my blood sugar would be cruising along nicely at 3,000 rpm. So my point to you and Chris, are you not missing out on the fact that some (or maybe a lot of) people may not be properly diagnosed as insulin resistant because they’re blood sugar is normal and healthy, but since the medical practitioner never checked the fasting insulin (or NMR), we could be missing the diagnosis! Check out this video of a wrestling coach who had great fasting blood sugar and normal basic cholesterol numbers. But guess what they find out when they dig deeper and find out he’s severely insulin resistant and is at amazingly high risk of cardiovascular disease: http://www.youtube.com/watch?v=an6L9VY0v8A

      • veronica says

        Couldn’t agree more Howie. If you are insulin resistant, and still producing lots of insulin to compensate, then you are effectively wearing out your pancreas. So, yes, I am sure that there are many people out there that are not being diagnosed. I’ve got the other problem of not producing enough when I eat food, so 20g gives me a huge spike, but, funnily enough 75g of glucose doesn’t have any effect on me ! ! an annommaly I know. Most of the time I don’t actually produce enough insulin, hence very low c-peptide, but if I take glucose then I produce insulin ! So far, no-one has been able to give me a sensible answer on that one.

  29. Howie says

    Isn’t fasting insulin a far superior measurement of insulin resistance than blood sugar, which is what we’re really concerned about? A lot of people will have “good” blood sugar levels of 80 or below (like me), but my fasting insulin is around 9 uIU/mL (good is below 3). I have ragingly high insulin levels that are keeping my blood sugar down, so as a clinician, do you not worry that you’re missing the whole story? Love what you do and thanks for letting me have a voice.

    • Cory says

      Howie–How do you correct insulin resistance? Is it meds or diet? Could you elaborate. Think I may be dealing with this–and causing hypoglycemia issues

  30. mia says

    Hi Chris,

    It is really helpful to read your blog.

    I have family history of diabetes. My mother has it at the age of 52
    My age is now 30. I was overwight for 2 years during and after pregnancy (80 kg. my height is 5.5). I reduced my weight to 60 in 2012 but I have put on again 5 kgs. now I am 64-65 kg. I tested my FBG using home glycometer it was 94 and 99 on next day. my post meal BG was 104. I am worried that I either have prediabetes or diabetes because of family history and my reading.

    2-3 years back these readings were FBG 75 and Post meal 95.

    are home glycometers correct? am I at high risk for diabetes?

  31. Hilary says

    Hi Chris

    I have had a sweating problem all my life. I have been told that I have an over-active sympathetic nervous system but thought it might be related to blood sugar levels. I had some fasting tests done and the only reading I can remember was Hemaglobin (I think) of 4.3, which is apparently normal. I, however, get thrush at the slightest intake of any sugar, I’ve probably had thrush hundreds of times and so now I do not consume any sugar at all. Do you think, that my sweating problem could still, somehow be related to something to do with my blood sugar? Please help

  32. Polly says

    Thank you for this article. Question. I am not overweight, I exercise and eat pretty darn clean 80% Paleo. My A1C levels have been 5.6 then with diet change 5.4. To me, this is not acceptable. My doctors response is exactly how you described above. I do have thyroid problems but seem to be Ok with levothyroxine and cytomel. I have terrible chronic back pain. I also have pretty bad IBS/leaky gut. My naturopath told me I do not detoxify efficiently. I take milk thistle now and chlorophyll. Do you recommend anything to help detoxify. Any shake or supplements that help? How can I get these sugars down?? Please help?

  33. Frank says

    Great website sent it to my daughter’s who are experimenting with paleontology diet. My glucose runs between about 118 to 140 daily a.m. testing but I have a 5.5 A1C …it was at 6 …and highest 6.5 according to a.m. fasting test I have diabetes (diagnosed in 1984 along with bells palsy…have had 7 cases since then) the other test I don’t. I watch my diet well as I have other neuropathyies. Drs (neurologists etc)scratching thier heads. One point agent Orange was dropped right on top of me and my team on several different occasions in Vietnam. VS says I have diabetes with palsy as secondary. Can I have at times diabetes and at other times not have it. Can it go into a prediabatetic state? Bottom line can it appear to be cured of can it be cured with diet and exercise. Thks you are really doing a service here…

  34. Suz says

    Hi , i hav a question, i had a fasting blood test. Only thing is because i was vomiting daily i didnt fast properly. Now my G.P is sayin i hav diabetes as my report came bak wid sugar level of 9.8 . What i want ti know is , is this accurate ? Is ther any thing i may not b diabetic ? Im a bit confused

  35. kris says

    Chris, I respectfully disagree with your criticism of the glucose tolerance test, although its true that “real world” diets do not reflect it, that’s the point, with so much variation in diets, the glucose tolerance test is neutral, a person who for instance does poorly but in real life conditions and diets is okay, is not indicative of the person doing fine, rather the person’s diet may be different, and they have delayed syndromes due to their gut or other factors, for instance if a person’s body slowly converts carbs more than others to glucose, that isn’t indicative of the test’s unreliability. Similary if a person passes the test, if could mean they have other problems, for instance dr. bernstein in his talk about the “Chinese vegetable effect” states that eating even a small vegetable can cause an increase of blood sugar because of the mismatch between glucagon and insulin.

    So regardless of these factors and whether folks are more sensitive to wheat, carbs, and other foods, the glucose tolerance test is a neutral factor, simply to measure how the body tolerates the end product of carbohydrates and proteins, glucose.

    Just because a person’s diet and body are different doesn’t make the test irrelevant or “artificial” because other factors influence the result.

  36. KWats says

    Hello… new to the board. I read your articles on blood sugar tests and abnormalities and have a question. My a1c is normal– below 5, but my fasting numbers are 95-105, and I have had postprandial numbers from 155-200, mostly 160-180, one hour after eating. Closer to 140 at 2 hours. 2 readings in 2 weeks above 200, with some dizziness and a great desire to lie down. I have been very tired and have had bouts of frequent urination, heat intolerance, and dizziness for a few years. I have had no appetite or thirst for about 6 months, and have lost weight (from 115 to 100 pounds). I visited an endocrinologist that tested me for autoimmune diabetes and the test was negative. He does not think I have an endocrinology problem and hopes I feel better. My thyroid is normal, and my ANA is negative. The only abnormal tests I have had are low potassium, low alk phos, and low ck. Are the sugar numbers abnormal and should I go back to my PCP?

  37. Margaret says

    I know I have very high cortisol levels however I am also concerned about my sugars. Tonight I conducted an experiment. I had 5 large buttermilk biscuits with artificial butter spread and a cup of skim milk. Total carb count 138 grams consumed in about 15 minutes.
    These are my glucose readings:
    1 hour later 128
    2 hours later 132
    3 hours later 129

    What does this mean? It seems like an awful lot of carbs but my numbers didn’t get very high but also didn’t drop very much.

  38. Andrea says

    Hi Chris,

    I came across this article about the potential connection of antibiotics to dysglycemia. Is the possible mechanism of action increased gut permeability due to dysbiosis? Just trying to put the pieces together and understand the full impact of modern pharmacy on our ancient body systems.

    Thanks for all you do! You really are my “does this make sense” meter!!


  39. cld9 says

    I am so glad I found this! I am 27 weeks pregnant and was recently diagnosed with gestational diabetes. I also have pregnancy induced hypertension and take labetalol to control the hypertension. I am also over 40 and this is my 5th pregnancy. My last pregnancy was over 10 years ago. Body shock and old age I suppose. My question is: Does the labetalol affect the outcome of the blood glucose test? My A1C was 6.2% and my average 3 month level @ 135. I was not prediabetic before. All blood work always came back normal. My doctors are more interested in numbers at this moment (which is ok, we want to keep the baby safe) but are refusing to tell me if labetalol may be a contributor to the higher glucose levels.

  40. feizel says

    Hi Doctor,My name is Feizel i am 55years old,I have blood pressure which is severe,meaning my last check up it was 199/132 and my sugar level is 19.2,please can u advise me on what i should be taking.My GP recommended Ridaq25g and Glycomin.Need advise please because i only just found out that i have blood pressure and a diabetic.Thanks
    Kind Regards

  41. LINDA says

    After a good all american dinner w/ potatoes filling my meter test in 216. and it stays on a declining high for 4 – 5 hours then it is 128 with no exercise. With exercise it is 109. My red blood cells are over the top at 48.3.

  42. susan says

    I’ve had a lot of similar things going on as the rest of you. My A1C was 5.8. I bought a glucometer and have become obsessive-complusive about checking my blood sugar. I have very high cholesterol. LDL 191. HDL 65. Tri 57. I was eating veg diet but I feel much better eating more protein. My blood sugar is very affected by carbohydrates. I had a hot fudge sundae last week and my bg level went up to 184 and dint go down for several hours. Fasting is usually 84-96. Post-prandial, deending on what I eat, it can be around 110 and as high as 184 if I eat high carb. I’m just wondering if I have prediabetes or if these readings are ok. Maybe I should just really watch carb intake. My peak blodd sugar sometime doesn’t happen until 2 hours after a meal and then it starts to come down. If I take cholesterol meds will it bring down my blood sugars?? Thanks for the comments.

  43. Veronica says

    Hi Kris
    I haven’t yet been diagnosed with diabetes but have had some odd numbers. My doctor was less than helpful and just suggested that I continue to eat normally. About a year ago I started to drink huge amounts of water and felt exhausted after eating and generally low energy all the time. I am a 60yr old female, weight 53kg height 5’4”, have a demanding physical job. Diabetes in the family. Anyway, my HbA1c was 6.2, fasting about 4.5. With no help from the doctor I immediately cut all sugar in my tea, never was a big cake/biscuit/choc eater anyway. Next A1c was 6.3, so I cut more carbs. next 6.3 again, cut carbs down to about 50g per day. Next A1c was 6.0 so it has come down but has taken a year to do it, but my fasting is now down to about 3.2. If I eat any grain products I spike quite badly. Why should my A1c have taken so long to come down when the fasting is so low? My c-peptide is within normal limits although on the low end of normal. I appreciate that you cannot give a diagnosis, but from your experience do you think that these numbers might suggest early stages of LADA?

    • molly says

      Veronica- I recently had some joint pain and visited a rheumatologist. She asked me if I was frequently thirsty and when I replied’ yes’ she tested me for Sjogrens Syndrome. I assumed my very dry mouth/increased thirst was from high blood sugar which has been high recently. Sjogrens Syndrome can also cause fatigue and joint pain- and is common in women over 40. Check it out. .

  44. Sara says

    I really need your help! I’ve been struggling with doctors taking my test results seriously and would like your input. I’ve had high igf1 and high growth hormone levels but suppressed during the ogtt test and was told I was just abnormal and would have to wait it out. My a1c was actually low 3.8 and average gluclose in the low mid 60s (I am not diabetic). My endo said this was actually good, despite my feeling awful all the time, because he sees such high readings normally. I also have had decreasing low platelet volume.
    Any input you could give to me would be greatly appreciated

    Thanks and keep up the good work!!

  45. Elspeth says

    Hi Chris, Thank you for your valuable insights on a myriad of issues. I’m wondering if you know how effective l-arabinose is as a “sugar blocker”. My friend is thinking of trying a range of products from a company called Ludaxx. They are called F21 (which contains l-arabinose and a polysaccharide “PSK”), a KonLi (a herbal tea) and PEARL. They are meant to aid in blood sugar control, weight loss and increased energy. I would value your opinion on them. Thank you.

  46. Matt says

    Hi Chris,

    Would really appreciate your thoughts on weight loss. If I am considered a “pre diabetic” now and weigh 110kg, am I really ably to reverse the chance of diabetes if I loose 15kg and bring my BMI into normal range or is the damage already made? Already, I have changed my fasting BS levels from 5.8mml mml to 4.9mml but that could just be a change in food consumed and increased exercise. Also, after fasting and 45 minute run, my blood glucose went from 4.9 to 7.5 breifly post run…. is this normal for non diabetic? I really would appreciate if you can explain this to me further.

  47. Stephanie says

    Hello Chris,
    Thanks so much for your great web site and kindness in helping others.

    Based on what you mentioned regarding anemia and falsely low A1C, my situation is rather odd. I am 50 yrs old, a vegan for 24 years, and have always had low hemoglobin with no other symptoms, great energy and great lipid profile. (As an interesting aside, my mom, a big meat eater, has always also had low hemoglobin as well). However my A1C is elevated, with a fasting glucose of 94. So while the FBG is somewhat normal (though I know you said this is higher than than the “real” normal), I would expect my A1C to be low (or falsely low) due to the anemia, since the FBG is in the somewhat normal – or at least not way out of normal -range. I also have low B12 and wonder if I get that up to normal levels could I fix this situation and maybe this is affecting the A1C reading? ( I dont have the A1C number yet but was told it is “elevated”).

    Thanks so much for any thoughts/suggestions!


  48. NovaGuy says

    Confused with reading my BG tests !
    I had in the LAB the FBG 126 and my A1C 5.4%. My doctor told me I was diabetic while I was in shock and disbelieve because I never have any taste for sweets, never I’m thirsty nor I did have any other symptoms diabetes has. For one month I did BG tests home, 3-5 times per day.

    Results from my home test:
    FGB : from 84 to 118, most of them were under 110
    2 hrs after breakfast : from 100 to 126 ( 1 slice of bread, butter, honey, butter, yougurt)
    2 hrs after lunch : 84- 120
    2 hrs after dinner (84-135 ) most of them were under 125.

    Every time I have a beer for dinner, I get my FGB under 85. My lowest ever has been 70.

    Exceptions (2 in total):
    1) 2 hr test after dinner did go 151, after 45 mins good exercise did go to 70 !!!!
    2) 1 (one) hour test after eating pizza for dinner, did go 172 but after 2 hrs did go back 116. I did not exercise to see how well my body would work.

    Am I diabetic ?
    Thanks in Advance,
    A NoVaGuy.

    • Chris Kresser says

      This is something you need a clinician to look at firsthand, and there are other factors to consider. Your FBG puts you in the pre-diabetic range (if above 99), but your post-meals look fairly normal with the exception of the readings >120 at 2-hours. The one-hour reading of 172 definitely indicates problems with glycemic control. I would run some more 1-hour tests. Seems you may have problems with your first-phase insulin response.

      • NoVaGuy says

        I appreciate your help. You articles (part 1 & part 2 about prediabeties) really made me have another look of understanding diabeties. Being in conservative side of the GB level only helps.

        By coicidence, yesterday was my 3 months check test for FGB. It was 87 while my A1C 5.7%, up from 5.4%. My FGB was consistant with my home tests for the last few weeks but I can’t figure out the cause of A1C going up. Even though under the Keiser Permanente result shows as a normal range, definately I’m keeping a close eye on it, considering it a pre-diabities level.

        ALSO I have to mention and I want to share with everyone, not a surprise for most of you but I have figured out that exercise REALLY, REALLY helps a lot. For the last few weeks, FBG has been under 88, 1 hour tests have been less 110, almost all of of them less than 90. I haven’t cut what I eat but how much I eat. I eat ‘normal’ sizes, probably twice as big hospitals normal sizes are. With exercise I can keep my GB always under control. (regardless if I eat honey, whole weat bread and soups, fruits, pizza, butter& bread, yougurt, cheese, milk, a combination of them or whatever – I don’t eat a lot though as I used to and I eat most of the times organic food). Now I’m doing 5 tests a day and making sure that at any random test of my GB is under 120. I really hope that my experience can help someone who may overlook the excercise, as I personally did before.

        Chris, thanks you a zillion times for helping people like me,
        Regards from Virginia,

      • Prasanna says

        Hi Chris,

        I also have the same problem. My fasting BG is around @100 (97-104) and shoots to 180-200 after an hour of meal(especially dinner). But it comes back in range (120-140) after 2 hours. Do you think this OK? What action would you suggest otherwise? Please advice.

        Thanks in advance.


        • raja says

          Hi Prasanna,

          I am also having the same problem as you..My fasting BG is around @100 (90-107) and shoots to 180-200 after an hour of meal(only after dinner). But it comes back in range (140-170) after 2 hours of dinner…Can you help me as to what I have to do?

  49. TH says

    Here’s an odd one for you (at least I hope so)… Had blood drawn right before colonoscopy (aggressive prep…started earlier and consumes 33% more PEG 3350 just to make sure gastro didn’t have wiggle room on quality of prep)… LDLs came back elevated (expected, I stopped statins to see what weight loss would do for me…not much) and blood glucose came back darn near at diabetic levels.

    I told my GP I was obviously dehydrated. I also secretly wonder what PEG 3350 did to my metabolism of the yellow gatorade I had 8-10 hours pre-draw.

    Could dehydratation account for the blood glucose travesty? Any data on sensitivity of BG to dehydration?

  50. Rose says

    My BG reading has been 103, 106 once it was 136 with no medication how am I doing and why are numbers higher sometimes in the morning. Last night I was 103 the first thing today 136 I expect tonight to be 110 or so.

  51. suzanne says

    thanks for your interesting blog.
    i just had a fasting glucose/insulin test with 75 glucose drink
    i wanted this test because after oatmeal or granola i often get a sugar crash.
    apart from the above i have no other health problems.
    my glucose reading was 5.2, then after one hour 3.8, then after two hours 2.9
    my insulin reading on the other hand was14.4, then after one hour 406.0 !!! then after 2 hrs. 216.0
    my doctor was not at all helpful in explaining to me why my insulin spiked so after one hour and my readings on the internet for hours, was not fruitful either.
    how would you interpret my high insulin peak (combined of course with my low blood sugar?).
    i thank you sincerely in anticipation.
    suzanne la rose
    hornby island
    b.c. canada

    • Elenor says

      Suzanna, I think it’s Dr William Davis (in his book Wheat Belly) who discusses how oatmeal is has a hugely bad effect on blood sugar — even the b.s. of ‘normal’ (non-diabetic or non-pre-diabetic) folks. As delicious as oatmeal is please try switching to eggs for breakfast for a week (even hard-boiled, if you have harried mornings) and follow your b.s. to see how it goes. My back-of-the-envelope thinking would be that the insulin is ‘controlling’ the high blood sugar reaction: your blood sugar drops and drops, because your insulin is insanely high! You might look online to see if there is something about your pancreas slamming out massive doses because it’s on its last legs? But I’m not a doctor, I don’t play one on TV (or the internet); this is just something I’ve read about. Have you read around here? http://www.phlaunt.com/diabetes/ and http://bloodsugar101.com — really excellent info!

  52. Rose says

    I just got diagnosed , my ac1 was 6.8 today I went to get my meter and my blood sugar after eating is 116 and whne I awake it is 117, I do NOT want medication so I am trying excercise and diet, should I be more alarmed at those numbers, ny dr wanted me to immediately go on meds.

  53. Cari B. says

    Please, I am a 54-y-o woman, BMI 19.2, plant-based diet, and largely vegetarian so most of my calories come from complex carbohydrates and fats (LOTS of nuts. Really lots). Lipid profile and lipid NMR are spotless….really-truly. But, A1c is now 5.6. Post prandials are usually fine and return to < 100 mg/dl in an hour. But a.m. fastings are nearly always 95-105. Why, why, why? When I try to restrict carbs, I drop weight instantly and can not for the life of me gain it back. Why is this happening? Fasting insulin was undetectable, with a normal c-peptide. The endocrinologist told me to quit worrying…..that nothing is wrong. But I am not convinced and am actually frightened to death. Can you shed light? Thank you so much!

    • sand thomas says

      sounds to me like you are doing fantastic! the A1c is a projection of future 3 mos. i would not worry about it at all. your 5.6 is great! on my lab report, my A1c was 5.7 and it said that they want it under 5.6. so, it sounds like yours is fine! good luck
      i would incorporate some animal protein once a week if i were u. it has nutrients in it that u r not getting w only plant foods. i was a vegetarian for 7 yrs. my health went downhill until i went back to being a carnivore!

    • says

      Absolutely blood sugar levels can and DO increase when you are sick. Any stress, including illness, can trigger hormonal changes that elevate our blood glucose. Mine typically rises 10-15% during times of illness.

  54. sand thomas says

    i monitor my bg daily when my diabetic husband does his. my bg always is between 60 – and no higher than 111. i had lab work done and my bg was 104. my a1c was 10.0. the dr. said i am diabetic! how is this possible? i am in good health, lift iron, rollerskate, dance, bike and trikke. will be adding swimming this winter too. i am 68 and feel fit and healthy. i eat low carb, lean meats and lots of veggies. no grains or milk. but allow yogurt. my husband had the blood work done at same time. his glucose is always over 300. it has been as high as 600. his a1c was 6.5. do you think they could have had a mix up? i am very confused. can you help?

    • says

      Something is certainly confused there. When I was diagnosed as a Type II diabetic my fasting BG was 267 (much higher post-prandials) and my HbA1c was 12.1%.

      The 10.0% HbA1c converts to a 24hr average blood glucose level of 240 mg/dl. The 6.5 converts to 140 mg/dl.

      The 10.0 is most-certainly a diabetic number. Depending on who you talk to the 6.5 is considered diabetic or pre-diabetic. In my opinion, it’s most certainly a diabetic number.

      Both the IDF (International Diabetes Federation) and the AACE (American Association of Clinical Endocrinologists) state that 140mg/dl is where damage starts to occur, and both recommend that even post-prandial (after-meal) numbers stay NO HIGHER than the 140mg/dl level. Myself, I like to see my post-prandials no higher than 120mg/dl.

      • Karen says

        Hi Glen,
        I just found out that my fasting blood sugar is 267. I typed it into google and was brought here to this discussion board. Can you offer some encouragement by telling me what you have done to improve your health (diet/meds) and what your numbers are now? I feel overwhelmed. Thanks.

  55. John says

    I have Sjogren’s Syndrome and am afraid that I may be coming up with Type I diabetes.
    My fasting blood sugar as measured by glucometer is in the high 90s (95-99).
    My HbA1c was 5.4%.
    While those numbers alone wouldn’t get me clinically diagnosed, my fasting BG levels have been rising, I have urinary urgency, +ANA (1:160), weight loss, dry mouth, dry eyes (that may be due to SjS).

    I understand that Type I diabetes may have a rapid onset of months to even weeks.
    What would be the best set of tests to determine whether my immune system is attacking my islet cells and I am losing the ability to produce insulin. Would I have to just wait for the effects to show up or are there tests that show specifically if this process is taking place.

    • Leslie says

      Hi John,
      I have Sjorens Disease, too. The dry mouth and eyes is part and parcel to the illness.

      As for your numbers, you need to see an Endocrinologist ASAP to discuss those concerns. My numbers are similar to yours.

      Type 1 is an auto-immune issue where the body attacked the cells of the pancreas responsible for producing insulin.

      Because you already have inflammatory auto-immune illness, you do have a greater than average risk of developing other auto immune issues. I’m in the pre-Type 2 diabetic stage. I was diagnosed with Sjogrens, Lupus, Hashimotos and Scleroderma, and Fibroymyalgia all in January, 2009. Once the body begins down that path, you have to pull yourself up by your bootstraps and make many lifestyle changes. It’s just the hand we’ve been dealt in this life, sorry to say.

  56. Jeff says

    Hi Chris, in recent months I seem to have succeeded (or so I thought) in lowering my BG levels with dietary changes. I test every morning on waking and at varied times through out the day (before/after meals etc) and have a 90 day average reading of 6.3 which according to the Diabetes uk calculator should give me a HbA1c of about 6. Calculating it with the formula: 90 day av + 2.52 / 1.583 gives a HbA1c of 5.6 yet my results have come back with an HbA1c of 6.9 which would mean my average BG would have to be about 8 – 8.5 and it is never that high. In the last 6 months I’ve quit smoking, lost 22lbs and thought I’d considerably lowered my bg. I feel I could cry, all the effort and then getting that result back.Could the test be wrong?

  57. says

    Chris, I read this article on testing blood sugar levels. I am confused about which tests are meaningful for a monitoring, maintenance? My Mom is Type 2 and one nephew is Type 1. I am attempting to understand and monitor Mom’s condition long distance, third person. Thank you, VeraMae

  58. bentzurm says

    I’m assuming you will delve into how you use post-meal blood sugar in the following posts, so I’ll be patient and save all my questions about that for that post. thanks.

  59. bentzurm says

    chris, when talking about OGTT how do you take into consideration the physiological insulin resistance one acquires from being fat adapted via a sane paleo nutrition plan? Both Peter from Hyperlipid and Robb Wolf have written about this. Do you consider it still useful? apart from that I just don’t feel comfortable with giving anyone such a bolus of pure liquified glucose, even for testing sake.

  60. Chris Kresser says

    Jim: I don’t see why they wouldn’t be. Alcohol also causes fatty liver, which could explain your lipid profile.

  61. Jim says

    Chris, thank you for the reply. You’re very kind to take the time, not just for me but all the other questions you’ve addressed in the past. And, you also have one of the very best health and nutrition blogs I’ve seen.

    My brother had an interesting observation about the beer consumption: he stated that it seemed to increase when I gave up wheat a few years ago, and we wondered if the exorphin polypeptides present in wheat and barley might be present in beer, as they were in the pasta and bread that I used to “love” to eat.

  62. Chris Kresser says

    Great find, Pål. Yes, there are quite a few studies in the literature proving the inferiority of FBG and A1c to OGTT for predicting future diabetes.

  63. Chris Kresser says

    Yep, the beer could definitely do it, via impaired liver function. Would also be worth exploring cortisol and other mechanisms, because your diet (aside from the beer) sounds good. A few potatoes a week wouldn’t explain those numbers, which as you know are well into the pre-diabetic range. Testing your post-meal blood sugars on a day when you drink beer, and a day when you don’t, would be a good next step. Also after you eat potatoes.

    • Sharon says

      Chris, I was diagnosed with prediabetes over a year ago. This was determined by an A1C test of 5.9.
      My fasting blood sugar was 78 at the time..Ironic, huh?
      After avoiding fruit (only eat berries now and then) and being very low carb, I brought it down to 5.7 by last February. Again, the fasting BS is always good..low to mid 80s. I’ve been now testing at home and most post prandials are in the high 80s or high 90s. I ate one sweet potato with a meal a few weeks ago and my post prandial tested a whopping 143!
      I am giving up all starches because I think they are a problem for me.
      I practice intermittent fasting (16 hours fasting) I follow some of the principles of the Warrior Diet. I would love your opinion on that. Does intermittent fasting do harm or will it help. I lost 8 lbs participating in it. I weight about 110 now. My waist went down to 27 from about 30 or 31.
      I’m 56 and I’ve been working out for 27 yrs. so you can imagine how shocked I was to be slapped with the pre diabetic label. Ok, ok…I was a chronic sugarholic and cut way back on it but obviously not soon enough.
      I do HIIT or Peak8 Cardio and I pump iron. I take after dinner walks almost every night.

      Any other suggestions to come up with a better A1C. My other sugar levels always look great. My last Triglyceride measure was 75.

  64. Jim says


    I had a VAP panel done a couple of weeks ago and was disappointed to find that in the 3 years since the last VAP, I have changed from pattern A/B to pattern B. Subclasses are: LDL4=25.2, LDL3=56.9, LDL1=5.7. My fasting glucose was 117, CRP=2.3, Cystatin C=1.17, A1c=5.6, Insulin=6.9.

    I avoid wheat and other grains, vegetable oils, and do eat meats, coconut oil, pastured butter. In congruence with the Perfect Health Diet, I have begun to eat a bit more starchy carbs like potatoes a couple of times a week and sweet potatoes about once a week. I do drink too many (5 or 6 per day) light beers with about 5 grams carb each. Is that the ‘problem’? Also, I just turned 70YO, don’t take any meds. Any thoughts would be much appreciated.

  65. Chris Kresser says

    Tim: your lipid profile looks great to me. I wouldn’t be worried about high LDL if your TG/HDL ratio is good, which yours is. But sure, improving insulin sensitivity is always a worthy goal.

  66. Tim Huntley says


    Thanks for the advice re: reducing carbs and investigating cortisol. I thought I was doing pretty good on the carbs (eating a WAP diet), but as I have begun to pay strict attention to everything I eat, it seems I have been eating a lot more than I realized.

    I have also been reading about the enzyme HMG-CoA reductase and how insulin stimulates it which in turn causes the liver to make more cholesterol. Would you expect that lowering average blood glucose levels, which should lead to lower average insulin levels would then lead to lower cholesterol carried by LDL? My current lipids are TC 241, LDL 161, HDL 64, and Triglycerides 64 (and while the LDL is “high”, it is almost all pattern A – big and puffy).

  67. Chris Kresser says

    Yes, it’s an exciting time in the field of autoimmune research and treatment. I did see the vaccine study, but because of the danger vaccines can present I’m far more inclined towards using nutritional compounds to regulate the immune system. Huge strides have been made in this regard over the past several years, and especially over the last two to three years. I’m wary of Big Pharma’s role and don’t trust them to prioritize safety and effectiveness over profit – in autoimmune disease or treatment of any other condition.

    • Kate says

      I’m just learning more about pre-diabetes as I’ve had some high numbers in the last while–and have experienced off the charts stress in the last couple of years. You mentioned investigating cortisol levels (which I understand are affected by stress). How is cortisol tested for? Thanks.

  68. Eva says

    Chris, you are so cool for answering everyone’s questions! I learn a lot of additional useful info from the Q and A. Speaking of diabetes, I thought you might find this interesting if you haven’t already heard, but looks like they are working hard and doing very well on an apparent vaccine of sorts for type I diabetes and this approach, if successful could well be also useful for all kinds of other autoimmune diseases. As usual, it focuses on containment instead of prevention or cure, but I would not be very surprised if it became the next big pharm cash cow:
    We can only hope that at least its benefits will outweight damages (fingers crossed). One thing is for sure, there is a very big and growing market for effective autoimmune disease treatment.

  69. Chris Kresser says


    From what I’ve read, even relatively quick spikes can be harmful, but the effect worsens the longer they are elevated.

    A much better strategy, in my opinion, would be to avoid the spikes in the first place by not eating the foods that cause them, and by working to address the underlying mechanisms. Just my 2 cents.

  70. rmarie says

    Chris, I’ve been wondering about something re A1C tests and BG spikes for which you may have the answer:

    How long does the blood glucose have to be in the blood to bond to the hemoglobin. Is it immediate? For instance if a high BG spike of say 180 is brought back down quickly (without medication) does it have enough time to bond? (and influence the A1c test result)?

    I’m asking because I have learned a little trick. For example, if I eat something I suspect may raise my BG I test it after 1/2 hour and if it’s high, doing 60-80 jumping jacks will lower it 30-40 points within 10 minutes. Works every time and I have NEVER experienced hypoglycemia. My base line tends to stay around 115-120.

    It’s very convenient and quick without having to spend an hour running or bike riding.

    • Jo says

      I thought that with exercise too but if the food was high enough glycemically…try testing your bg again after a while from the exercise. I think you will see the dramatic lowering from exercise was temporary.

  71. Chris Kresser says

    I’ll explain how to cheaply and easily measure post-meal blood sugars in a future article, which is probably a more accurate indicator of CVD and diabetes risk than OGTT anyways.

  72. rmarie says

    I am definitely pre-diabetic (have been for at least 10 years that I know of) and yes, my doc never said anything because it was usually well below 126. One of the reasons I’ve never taken an OGTT is that I weigh 89 lbs and I think drinking 75 oz glucose for such a small body is irresponsible. And they probably wouldn’t adjust it. I watch my carbs and things have not gotten worse over all that time. I’m in my late 60’s.

  73. says

    Hi Perkdoug- I did test it after several exhaustive sprint workouts and I now know that they definitely elevate my BG for a while. I didn’t really ever get super high readings though, usually between 95-115. I really don’t know how this compares to a healthy BG response to exercise but it doesn’t strike me as too excessive.

    Thanks for the tip.

  74. PERKDOUG says

    Tyler the sprinter:

    Test your blood sugar immediately after a high stress workout and you might see an unfriendly blood sugar level.

    Just an idea that could explain the high A1c.

  75. Chris Kresser says

    This is exactly what I was talking about in the article. I can’t understand why a doctor would be “pleased” by an A1c of 5.5 when 5.6 is often considered to be pre-diabetic. That’s lunacy. Does some magic button get pushed between 5.5 and 5.6 that changes everything? I don’t think so.

    As I’ll explain in the next article, nerve damage, beta-cell destruction and other complications begin to occur as blood sugars rise over 140 mg/dL. Believe it or not, heart attack risk increases in a linear fashion as A1c rises above 4.6%. Granted, the increase in risk from 4.6% – 5.5% is very mild, but from 5.5% – 6.0% it goes up significantly.

    You may need to reduce your carb intake. There are several other potential causes of high blood sugar, such as high cortisol, so that might be worth investigating as well.

  76. Tim Huntley says

    Hi Chris,

    Thanks so much for this article. I am new to reading your blog, but am very interested in learning more about blood glucose testing. I recently had some blood work done and because of a flaky reading on a fasting glucose test, my doctor reordered the test and an HbA1C test. While she was very pleased with the results (fasting of 90 mg/dl and A1C 5.5%), I thought the A1C seemed high. I purchased a blood glucose meter and have been doing some testing over the past week. So far the highest reading I have seen was 2 hours after eating a breakfast of oatmeal with butter, coconut flakes, cashew butter and about 2 Tbsp of honey. It was 141 mg/dl. That seems fairly high to me (for a presumably healthy person). Thoughts? (and FYI, I ate the same breakfast this morning without the honey and only hit 110 mg/dl)

    My plan is to continue testing after meals that are higher in carbs and see what foods tend to cause the highest spikes.


    • Seagal says

      Most type 2 diabetics (non-insulin dependent) have increased b.g. after eating something carby like oatmeal with honey. An alternative could be flaxmeal porridge with coconut oil and cream. Mix a couple of tablespoons of flaxmeal with the c.o. & cream and heat. Add whatever sweetner you choose.

      BTW, my b.g. would probably be around 180 with the same meal.

      Best wishes…..

  77. Chris Kresser says

    Jesse: lab ranges are mostly determined by taking a bell curve of the results of those who get tested. And that is a huge problem I will be addressing in a future article.

    Java: eating will affect blood sugar, that’s why to obtain a fasted blood sugar reading (to see how the blood sugar behaves in a fasted state) it is necessary to fast for 12 hours. Many other things, such as cortisol levels, will also affect blood sugar in the fasted state. Being adequately hydrated is a normal physiological state, so yes, you should be adequately hydrated to avoid skewing the results.

  78. Jesse says

    Hey Chris, what research are these tests and numbers based on? It’d be interesting to see how they came up with such values. Or were they just made up from nothing?

  79. java says

    Amazing article..does a state of fasting , as in early morning blood tests alter scores. Should one ideally hydrate before these tests. But then what is ‘normal’ ? Tests done in a state of hydration or tests done without hydration ?

  80. Chris Kresser says

    A normal life cycle for a red blood cell is 120 days. So when I say “permanent”, I’m just referring to that period of time. It’s absolutely possible to change A1c levels with diet.

  81. says

    Dear Chris

    I’m not well-informed on this important topic, so please excuse my question. You write that “The higher your blood sugar has been over the past three months, the more likely it is that glucose (sugar) is permanently bonded to hemoglobin.” – Is this absolutely permanent? – Or does the bonded hemoglobin eventually get broken down so that the person ‘gets another chance’ at regaining unglycated hemoglobin?

    Thank you very much for your interesting and informative blog.


  82. says

    I can’t say I remember my hydration status at the time, I’m usually well hydrated but it’s definitely possible that I wasn’t. I’m going in for another one soon and I’ll make sure to hydrate well.

    The previous months were physically stressful as I was doing manual labor all day, training for track, and weight lifting, but not mentally stressful. I was also during intermittent fasting at this time (probably stupid idea considering the workload). Certainly could have elevated cortisol.

    I’ll let you know the results from the next test. I really appreciated the answer, thanks again.


  83. Chris Kresser says

    Only thing I can think of that wouldn’t elevate FBG and post-meal BG, but would elevate A1c is dehydration. In this scenario, your hemoglobin would still be in the lab range but outside of what we call the “functional range”, which is the range that reflects optimal health. Polycythemia and erthrocytosis could do the same thing, but in that case your hemoglobin would be outside of the lab range.

    Were you under any additional stress during the previous 3-month period leading up to the A1c test? Cortisol elevations from physical (overtraining) or mental/emotional stress could elevate A1c, but we’d expect to see it in FBG and post-meal sugars as well.

  84. says

    Hi Chris- been reading your blog for a while, I’ve used the information from here to treat clients with really excellent results. Your research quality and the application of it is really top notch.

    Quick question – I’m 180 lbs, intercollegiate sprinter/jumper, following a strict evolutionary diet for ~10 months, diet was very good before that too, about 8-10% body fat, and overall in great health. However in my last blood test, my A1c was 5.7%. I tested BG values for 2 weeks afterwards and it only went over 126 twice, and was usually between 80-90 (while eating my normal lowish carb diet). The doctor was completely stumped as to why my A1c was so high, as am I. My other blood values were normal- TGs: 48, LDL: 91, HDL: 111.

    Any ideas off the top of your head as to why this would happen?

    Thanks a lot for the great info on the site by the way, you are an inspiration.


    • says

      A1C does not directly correlate to bg.

      For example, fructose can raise A1C, but not bg – I’m guessing that’s the cause as your LDL is a bit on the high side (gorgeous TG and HDL though).

      • Rose says

        That’s completely untrue. Fructose is a sugar just like any other. As a type 1, I am an ideal lab rat for “will something affect your blood sugar” and fructose is no exception. Watermelon is a fruit, the home of fructose, and it has one of the highest agreed upon Glycemic Indexes on the table!

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