The Dawn Phenomenon – T2D 8

posted in: Diabetes, Health and Nutrition | 109

The occurrence of high blood sugars after a period of fasting is often puzzling to those not familiar with the Dawn Phenomenon. Why are blood sugars elevated if you haven’t eaten overnight? This effect is also seen during fasting, even during prolonged fasting. There are two main effects – the Somogyi Effect and the Dawn Phenomenon.

Somogyi Effect

The Somogyi effect is also called reactive hyperglycaemia and happens in type 2 diabetic patients. The blood sugar sometimes drops in reaction to the night time dose of medication. This low blood sugar is dangerous, and in response, the body tries to raise it. Since the patient is asleep, he/she does not feel the hypoglycaemic symptoms of shakiness or tremors or confusion.  By the time the patient awakens, the sugar is elevated without a good explanation. The high blood sugar occurs in reaction to the preceding low. This can be diagnosed by checking the blood sugar at 2am or 3am. If it is very low, then this is diagnostic of the Somogy Effect.DawnPhenom2

Dawn Phenomenon

The Dawn Effect, sometimes also called the Dawn Phenomenon (DP) was first described about 30 years ago. It is estimated to occur in up to 75% of T2D patients although severity varies widely. It occurs both in those treated with insulin and those that are not. The circadian rhythm creates this DP.

Just before awakening (around 4am), the body secretes higher levels of Growth Hormone, cortisol, glucagon and adrenalin. Together, these are called the counter-regulatory hormones. That is, they counter the blood sugar lowering effects of insulin, meaning that they raise blood sugars. The nocturnal surge of growth hormone is considered the primary cause of the DP.

These normal circadian hormonal increases prepare our bodies for the day ahead. That is, glucagon tells the liver to start pushing out some glucose. Adrenalin gives our bodies some energy. Growth hormone is involved in repair and new synthesis of protein. Cortisol, the stress hormone increases as a general activator. After all, we are never quite so relaxed as deep sleep. So these hormones gently get us ready to wake up. A good ol’ fashioned hormonal kick in the ass, so to speak. Hormones are secreted in a pulsatile manner peaking in the early morning hours then falling to low levels during the day. DawnPhenom1

Since these hormones all tend to raise blood sugars, we might expect that our sugars would go through the roof in the early morning. This does not actually happen.

Why? Insulin secretion also increases in the early morning to counteract the counter regulatory hormones. In other words, insulin is there to make sure blood sugars do not go too high. However, if you look closely at the blood sugar readings, there is a slight increase in the morning time.

So, in the normal, non-diabetic situation, blood sugars are not stable throughout 24 hours. The Dawn Effect happens in normal people. This is easily missed because the magnitude of the rise is very small – from 89 to 92 mg/dl. However, this effect was found in every patient studied. So, unless you are specifically looking for the DP, you are likely to miss it.

Think about it this way. Your body has the ability to store food energy as sugar (glycogen) and fat. When you eat, you store food energy. As you sleep (fasting), your body needs to release this stored energy. Around 4am or so, knowing that you will soon be waking up, your body prepares you for the upcoming day. It does this by increasing counter-regulatory hormones to release sugar into the blood. You can see that glucose production falls overnight and starts to ramp up around 4 am. In order to prevent the sugars from rising too much, insulin increases to act as a ‘brake’ on the system.

Type 2 Diabetes

Balloon deflatedNow, what happens in the situation where you have T2D, or high insulin resistance? First, the technical explanation. Around 4 am, counter regulatory hormones surge and insulin is also released to counter this. However, in T2D, the body has high insulin resistance, meaning that the insulin has minimal effect at lowering the blood sugars. Since the counter regulatory hormones (mostly growth hormone) still are working, blood sugars rise unopposed, and therefore much higher than the normal non diabetic situation.Balloon inflated

In the non diabetic (normal) situation, the liver is like a balloon. You eat, insulin goes up and food energy is stored as glycogen in the liver. Since the balloon is deflated, the sugar goes in quite easily. As you fast, insulin falls and glycogen is turned back into energy to power the body.

Now, consider the situation of T2D. Over years of overconsumption, our liver is stuffed full of fat and sugar. As we eat, insulin goes up and tries to put more fat into a fatty liver. This is quite difficult. It’s like trying to inflate an overinflated balloon. The sugar and fat simply won’t go in anymore. That’s insulin resistance.OLYMPUS DIGITAL CAMERA

But what happens when insulin starts to fall? You have a huge fatty liver that wants desperately to deflate itself (see last post). As soon insulin falls, sugar comes rushing out of the liver and into the blood. This results in the clinical diagnosis of T2D, when doctors are able to see the high blood sugars. So, what do they do? They prescribe more insulin.

This big whacking dose of injected insulin keeps the sugar bottled up inside the liver. This means that the doctor is able to congratulate him/herself on a job well done. But nothing is actually accomplished. The underlying cause of insulin resistance is the fact that the liver is overstuffed with fat and sugar, like 10 pounds of sausage meat in a 5 pound skin. Nothing has been done to alleviate this situation. So, patients must inject themselves day after day. Over time, they require higher and higher doses. A year later, the liver is like 15 pounds of sausage meat stuffed into a 5 pound skin.JeffDaniels

In the Dawn Phenomenon, the body is under orders to release some of the stored sugar into the bloodstream. Like the overinflated balloon, the liver puts forth prodigious amounts of sugar in order to relieve itself of this toxic sugar burden. It’s like trying to hold a fart inside. As soon as we get to the bathroom, it’s ‘Fire in the Hole!’. When our liver gets the ‘go’ signal to release sugar, it does so in huge amounts, overwhelming the pitiful attempts of the insulin to keep it bottled up inside. That’s the Dawn Phenomenon.

The same thing is seen during fasting. Remember, there are hormonal changes during fasting that include increases in growth hormone, adrenalin, glucagon and cortisol. These are exactly the same counter-regulatory hormones as seen in the DP. These are normal changes. As you fast, your insulin drops. Your body then tries to increase the glucose in the blood by encouraging the liver to release some of its stored sugar and fat. This is natural. However when you have T2D, there is too much sugar released from the liver which shows up in the blood like an uninvited guest.'This is a 'placebo' line. It serves no purpose but it makes us feel good.'

Is this a bad thing? No, not at all. We are merely moving the sugar from the liver out into the blood. Lots of doctors consider it bad, because they are only concerned about the sugar that they see (in the blood). They do not concern themselves with the sugar that is hidden away.

After all, think about it this way. If you are not eating, where is the sugar coming? It must come from inside your own body. There is no other alternative. You are simply moving the sugar from storage, out into the blood where you can see it. It is neither good nor bad.

Insulin moves the sugar from the blood where they see it, and into the tissues (liver) where they cannot. It is no less bad, but they are able to pat themselves on the back for a job ‘well done’. it is not different from moving garbage from the kitchen underneath your bed. It smells the same, but you can’t see it.

I call drugs like these (insulin, sulfonlyureas) dracebos – placebos for doctors. They are medication that don’t actually help the patient in any way, but make the doctors feel better about themselves. You will still die of diabetic complications, but hey, at least the doctor has saved his/her own ego pretending that he/she did something about it. The history of medicine is the history of the placebo (and dracebo) effect.

In the IDM program, we typically use medications to keep blood sugars in a reasonable, but not low range during fasting. Insulin keeps all the sugar bottled up inside the body. If we stop insulin, there is a risk that it comes out much too quickly (like the overinflated ballon releasing all at once). So we want to use less insulin, but enough to release the stored sugars at a reasonable measured pace. A physician needs to adjust the medications to properly control the flow of sugar out of the liver.

The Dawn Phenomenon, or higher blood sugars during fasting does not mean you are doing anything wrong. It’s a normal occurrence. It just means that you have more work to do.

Some people have normal blood sugars except for the Dawn Phenomenon. This still indicates that there is too much sugar stuffed into their liver. They need to keep burning down that sugar. It means there is much more work to be done before they are cleared of their diabetes.

Think about it this way. The Dawn Phenomenon is simply moving sugar from body stores (liver) into the blood. That’s it. If your body stores are filled to bursting, then you will expel as much of that sugar as possible. By itself it is neither good nor bad. It is simply a marker that your body has too much sugar. Solution? Simple. Either don’t put any sugar in (LCHF) or burn it off (Fasting). Even better? LCHF + IF.

109 Responses

  1. Dr.Fung-

    Thanks so much once again for making Dawn Phenomenon so crystal clear.In my case as I understand…more work to do.I have started seeing results while I am on 24X6 fasting +LCHF & EXERCISE. Thanks.


  2. Thank you, Jason!
    This is the first time that I feel I have really understood DP.
    Does this mean that as my morning fasting blood sugars decrease and normalize, that my fatty liver is healing itself ?
    Thank you for your posts.

  3. Rene Tewksbury

    After stopping my massive doses of insulin and Metformin in July and 5 months of following your program, my BS stays in the 60s during my fasts with no DP spike. Thank you for giving me my life back.

    • Rene,
      how long do you fast? and how often? I quit all my diabetic meds 5 months ago but my numbers were in the 300 range for fasting blood sugars with LCHF. I needed to get my A1C better to renew my driver’s license so went on glipizide which brought my blood sugars down for a month and then they started climbing back up. After reading Dr. Fung’s plan I went off the glipizide because I felt poorly on it and had gone from 128 to 140 lbs in that 2 month period. I feel so much better . With fasting I got it down to 108 once but have had over 200 with IF.
      Even if my DP is high I think I will heal faster without the meds.
      Thanks for the encouragement.

      I have been following Dr. Fung’s blogs and have worked

    • Did you take yourself off the Metformin?

  4. In a long term low carb ((<50 gms/day) person, how can one be certain the DP (say 105-115 fasting BG levels) is not from Beta cells starting to fail + unable to secrete sufficient insulin? Many forums have low carb/ketogenic individuals with "pre-diabetic" levels of morning BG. Why would this be considering many have been low carb for 2-3 years or more?

    • The reply to the 2nd question would be “the liver stores did not empty”, extracted from what Dr Jason above wrote. And it is also visible in waist measure I understand. The remaining DP is also probably reason for halted weight loss. Re the first question, hardly an issue on LCHF with substantially lower insulin demand than before, unless type 1 is developed for whatever reason. If you must know, do a small glucose challenge, like eating a (large?) bowl of breakfast cereal with a slice of bread. Measure BG every 30 minutes and if it goes down below the initial within 1-2 hours, your beta cells are working fine.

      • Dr. Fung:

        So, re Evinx second Q, and stem B’s answer, which i seems to be a good deductive concussion from your explanation:
        is IF the only answer to decreasing DP, with waistline till too big, even after extended LCHF ? No doubt exercise would help too?

        FWIW, I have gotten my HbA1c down to 5.6 after incorporating IF into my habits, along with long term LCHF, but still have DP and fat around my belly.

        • Autocorrection strikes again: should be “conclusion” not “”concussion”

          Is there no better way to edit our comments?

      • HI STEN B,

      • Maninder Chopra

        If someone does have type 1 symptoms too, after being with type 2 for long time, how would the insulin/metformin strategy be used during intermittent or longer duration fasting? Would it make sense to bring the glucose level down a little bit, if it getting too high? And what would that reasonable cut off should be? I would really appreciate if someone brings clarity to this question.

  5. “Solution? Simple. Either don’t put any sugar in (LCHF) or burn it off (Fasting). Even better? LCHF + IF.”

    In cases where “the balloon is somewhat deflated” to borrow your analogy (i.e. where our glycogen reserves are relatively lower) – and even if we stay on a relatively LCHF diet – is protein consumption due to gluconeogenesis a concern?

    I.e. if low on reserves and our sugar intake is low due to LCHF, if I ate excess protein, would I be in danger of blowing the balloon up if there was enough protein consumed?

    LCHF + IF would seem to address that (i.e. no worries there about excess protein) – but wondering if being in a low glycogen reserves state would somehow trigger gluconeogenesis to occur with existing muscle mass? Or are we safe from that scenario?

    • I would also like to know the answer to this question!

      Would strength training be needed to retain muscles and Bones,etc?

    • Is it possible that after washing out glycogen reserves from “fat liver” there is start of gluconeogenesis from visceral (dangerous?) fat?

  6. We are merely moving the sugar from the liver out into the blood. Lots of doctors consider it bad, because they are only concerned about the sugar that they see (in the blood). They do not concern themselves with the sugar that is hidden away.

    After all, think about it this way. If you are not eating, where is the sugar coming? It must come from inside your own body. There is no other alternative. You are simply moving the sugar from storage, out into the blood where you can see it. It is neither good nor bad.

    This explains why Hubby spent last night in the 88-91 range (after eating), but woke up this morning (at 4:30) at 101. His post-fast test results from last week show insulin resistance at about 30% or less, depending on test (despite having a genetic tendency toward diabetes from his paternal line). This had my head buzzing until I read this article, because there is no dawn to trigger Dawn Phenomenon for Hubby. Evidently, there need not be actual dawn to trigger this.

    I hope you’re already working on a Volume 2 of your book, which will include everything you posted since it went to print. I want to add to my “Clarity” lineup and Obesity Code collection. Most of all, I want to see these books ON MY DOCTOR’S BOOKCASE! I sent her a copy of Cholesterol Clarity, but still don’t see it in her office–she probably dumped it.

  7. Dr. Fung,
    Thank you so very much for this blog, which I found in searching for
    ways to re-start my stalled weight loss. I’ve been on my first fast
    for 5 days now and have lost 10 pounds with 100 still to go. I’m
    wondering how quickly and completely the brain responds to fasting in
    lowering the BSW. For instance, if I fast for a month and lose
    significant weight, when I go back to eating will my body want to go
    back up ½ or 1/3 or ¼ of the way to my pre-fast weight or will it want
    to stay more or less at the weight I was at when I ended the fast? In
    other words, for weight loss, am I better off fasting for as long as I
    can at a time (which actually seems easier to me than a
    every-other-day fast, for instance) or am I better with smaller chunks
    of intermittent fasting?

    • Andrea,
      Based on Dr Fungs previous posts weightloss goes faster if you do longer periods of fasting. You will gain some weight once you start eating again, to minimise the weight gain you should try eat LCHF. Everytime you fast you should most likely see a bit more weightloss. To keep it off for good, you can do less frequent fasting than when you try to lose weight, and also maintain LCHF. Good luck!

  8. Although I still have “more work to do”, I have gotten my best results so far on a ketogenic diet with IF and HITT (High Intensity Interval Training). Before i went on this program, my blood sugars were averaging 15.4. The first time I tried a 24 hour fast my BG kept climbing until I started eating. At that time, it had reached 15.7. What no one seems to mention is that when the liver is synthesizing prodigious amounts of glucose due to hormonal imbalance caused by insulin resistance, liver/muscle glycogen storage is always full to capacity. HIIT depletes muscle glycogen at a faster rate than the liver can produce glucose. In severe cases like mine, HIIT and IF are essential.

    • David

      Wondering about your schedule for High Intensity Interval Training (HIIT) while fasting. Would like to know in details as I have hard time in lowering fasting blood sugar while I am on LCHF & Fasting & exercise (Not HIIT). Your suggestions will be of much help.


  9. For me the Atkins fat fast is what I can stick to, feel best on and get best results from. Blood sugars, hunger regulation and mood are par excellence, but there are dire warnings it is only to be done rarely as its unhealthy and shouldn’t be undertaken for longer than several days. I usually gravitate instinctively towards a higher protein intake after a FF. I would love to know Dr Fung’s thought on this – what if I drifted in and out of a FF what the health consequences would be, would the body catabolize lean muscle in order to meet protein requirements, would this lower my metabolism, increase fat mass etc.

    • Dire warnings from whom? When I”m not fasting, I eat as much fat — particularly animal fat, as I make an effort to avoid oils from vegetables and nuts — as I can. I add butter (from grass fed cows) to meat, for instance.

      • I’m talking about the Atkins Fat Fast which is a short term hack to get into ketosis quickly.

  10. Have only recently,like this week,discovered your website. I’m T2D past 10 years on metformin 1gm went up to 2gm 6weeks ago as my BGL’s were going up. Hba1c since then was 5.2, so actually pretty good.

    I’m so grateful for your generous giving of information Dr Fung! I have to have my daily read to keep me focused and motivated, and there is so much here to read.

    Have already started IF on a small scale, hope to do better after Christmas! I found fasting at work difficult as I was light headed and finding concentration difficult. Had to keep moving and changing tasks. Checked BGL’s and it was 7.8 after having not eaten for about 14 hours only. I guess my liver was farting!

    Thank you again

  11. Hi Dr Fung, I believe that I have read comments you have made in the past saying that the body can only store very little glycogen (the body’s way of storing glucose), so when we fast, how is it that the body maintains any glucose in the blood at all. If we are putting no sugars in and we have exhausted our bodies supply, shouldn’t our blood sugar drop to zero after a while? (a situation that would of course be terminal)

    Dr. Jason Fung: The liver manufactures new glucose in the process called gluconeogenesis.

  12. Jim Garrison

    On October 4th of this year I stopped 7 years of taking 100 units of Insulin every day since 2008. I read everything in your blog prior to that day, I think it took me 3 weeks to read everything. I started the LCHF diet about 45 days prior to Oct 4th. I started to fast and fasted for 30 days. Nothing but water with lemon and I thought it would be harder than it was. I had increased energy, I cook for my family almost every night and that wasn’t hard either. My very first fast at 58 years old and my A1C came down from 7.1 to 5.9. Thank you for your dedication and commitment to your patients.

  13. Thank you Dr. Fung for finally discussing Dawn Phenomena … I have not found much information on it, specifically for people that are not yet taking diabetic meds. I’ve been doing LC on and off for decades, but in the recent 2 years became very lax. I found your website (and Dr. Eenfeldt’s) earlier this year in a search to find a way to avoid becoming diabetic as it runs in both sides of my family. Your research and explanations here convinced me to try IF and ketogenic, and since September I’ve lost 20 lbs. I’ve not gone full fasting, but rather only eat dinner most days. Not only has it been easy to fit into my lifestyle, but I feel the IF is truly the key to kicking the body into fat burning mode. However I’ve been concerned about the BG readings remaining 120-145 in the mornings. Your explanation here makes me feel although I’ve not seen the decrease in morning BG readings, I’m still on the right track and should continue this program – not that I have any qualms about sticking to it since this is the most successful I’ve been in years at losing weight. I hope to get the courage to try a multi-day fast after the holidays… fingers crossed. 🙂 Thanks again for this blog!

    • January Update – On day 3 of a 6 day fast. My glucose reading this morning was 144, which is on the high side for me as it was usually 115-140 when I doing keto before the holidays. This evening I checked again and it was 88. That is the lowest number I’ve had since I began testing in September! Based on this post, I know my poor liver is just dumping all that accumulated fatty crap… and more importantly I know I’m on the right track!!

      Thank you, thank you, THANK YOU Dr. Fung for the wealth of information on this site and tackling Diabetes!

      • May Update – I’ve been tracking my glucose levels and the overall downward slope continues. While I still get morning readings in the 120-140 range, my afternoon readings have now regularly dipped into the 80s and even a 74 the other day… which I never saw previously! My official doctor’s ordered bloodwork two weeks ago showed a fasting reading of 151 (which is suspiciously high) but A1c of 5.6. Overall cholesterol was 224, but my HDL was 74… which contributed to the higher number. Overall excellent bloodwork and no talk of metformin despite the high fasting number. I definitely feel this program is helping me heal along with losing two sizes, which is just bonus. 🙂

        • Mary Anne Sautner

          Hi Karin, just read your post and was very interested in where you said your morning (fasting) blood sugar was 151 but your blood test a1c was 5.6! That is great! I didn’t realize your a1c can be that low while fasting BG is high. I still have hope!! Going for by blood work in 2 weeks.

  14. Thank you for a fabulous explanation of what is happening in my body in the morning. I guess I will add Intermittent fasting to my LCHF and put up with “hangry” (Hungry and angry), to expel the excess sugars still stored in my liver.

  15. Awesome article. You have answered quite a few questions I had about “why am I getting these morning spikes?” Or “why is my BS reading high when I’m only eating 20 carbs “or less” each day. It makes sense what you said. Thanks! A Lot!!
    For the record, I am a T2 diabetic and started about 2-3 weeks ago on a LCHF program/way of eating. So far, so good! I’m hoping that I deflate my “over stuffed” liver sometime soon. I know I can’t force this, but I can keep with the program and the body will hopefully take care of the rest. (as of tonight, my Ketostix are finally measuring “moderate”)

    Looking forward to hear more about T2 diabetes and ways to manage it! Best regards to you sir!

  16. Linda Tanner

    I have been off insulin for 8 months now & glipizide for 3 weeks (on glipizide only for 3 months AFTER off all MY INSULIN METFORMEN, ETC.
    With weighing 130 and having eaten for 2 days pretty low carbs, grass fed beef I want to water fast again but now afraid of the dumping sugars from my still fatty liver. B/s 250 but when fasting it went to 108 & 141. I was diagnosed diabetic 12 years ago.
    1 am 74 yrs old and weighed 115 when I married.
    I had gestational diabetes with first child but not my last two.
    I do not want back on insulin or any meds? Do I need to so my liver does not dump too much sugar at once?
    I have read most of your blogs from 2014 until this one.
    I thank God for your help Dr Fung!

  17. Could cholesterol lowering drugs be the ultimate “dracebo”?
    We blame Lipitor for my husband’s T2D.
    “Dracebo”: another very clever word coined by Dr. Jason, soon to be on many lips.
    Remember, you heard it here first.
    “Dracebo” describes in one word one of the biggest scandals in modern medicine. We are being drugged to death by most doctors.


    • Ruthy-

      Please read following article :If Statins Cause Diabetes, Why Should ALL Diabetics Take a Statin?

      In my case I did developed after taking Statins as it was prescribed by my Cardiologist after I had angioplasty. At one point I decided not to take statins & I stopped taking statins for three months.The results were shocking as my cholesterol levels went up. I was advised to re-start.Since then I am on Fasting +LCHF +Exercise which has benefited so much in bringing down all the levels to normal.

      Hope this will help you in understanding “Dracebos………

      • Dev
        Did you re-start the statin or did fasting etc. bring all your levels to normal without any drugs?

      • Dev,

        I do not understand your story. I have the same Q as Ruthy.
        Did your LDL go down Without the statins while practicing LCHF + fasting + exercise ?
        How much % down? As much as with statins? What type of exercise?

    • No, it didn’t show up here first–this term is also in the book The Science and Fine Arts of Fasting by Herbert M. Shelton (1934). I’m reading a reprint of this book now (from Amazon), and have run into this term several times, as Mr. Shelton himself opposed what was the conventional medicine back then.

      Reading about the history of fasting is fascinating to me, and a lot of what is now history is standing true in fasting today. Thank god we have Dr. Fung to reiterate info from the past AND the present (from current research) for easy access and learning.

      We definitely need more research into fasting like we got from the keto diet–remember the flurry of keto research that happened in the early 2000’s? I don’t think it will happen, because the Powers That Be (the ones who hold the purse strings) already know that fasting is (and will turnout to be) the end of medicine as we know it. For once, consumers will FINALLY be in control of their heath issues, and for minimal cost–in other words, WE will be the ones to bend the cost curve!

    • Heather Seeker

      It seems that we are being drugged to death Ruthy. Don’t know if your husband has had a heart attack or a stroke? If not, you might be interested in the “Number Needed to Treat” is a tool developed by doctors with no commercial links, to compare the benefits of drugs to their risks
      For statins, for someone without a history of heart attack or strokes, the NNT shows
      None were helped (life saved)
      1 in 104 were helped (preventing heart attack)
      1 in 154 were helped (preventing stroke)
      1 in 100 were harmed (develop diabetes*)
      1 in 10 were harmed (muscle damage)

      and concludes that overall there are no benefits to taking statins in this situation

  18. Ruthy

    I had to re-start the Statins (Crestor 20mg) & in order to bring down the Lipids & Sugar & triglyceride levels I adopted three fold strategy i.e. LCHF +Fasting ( 5 : 2) +Exercise & now I have to maintain these levels.I still find that my fasting blood sugar readings in the morning are around 7.5 which should be within normal range. Crestor does causes joint pain but if you take COQ 10 at bed time you should have none.


  19. Thank you for the link to the page discussing the statin Diabetes link and the difficulties exercising while on statins.

    Luckily, I have had no cardiac problems requiring any intervention.
    But my internist believes, strongly!!!, that I still need Lipitor for prevention, since my ApoB , LDL-c etc are well above the highest acceptable cutoff.

    I also did a trial of droppin off the statin, and retesting after a few weeks with newer tests of ApoB and LDL particles as well as the tradional total Cholesteol etc and calculated LDL-C.
    My LDL-C levels reverted to almost the exact levels they were before I first started on statins fifteen years ago. The results were so similar, it seemed uncanny.

    I am hoping that more fasting, and perhaps therefore less saturated fat (its effects may very among individuals?) will bring down my LDL enough to lower or drop the Lipitor dose.

    However it may be an issue with my receptor that is genetic? I do not believe any diet-related research has been done to clarify these questions, so we must self experiment,.

    • Have you read The Great Cholesterol Con by Malcolm Kendrick? It offers another view of all of these tests. I personally think they don’t mean anything.

  20. Hubby completed a 2-week fast, had testing done, and his small LDL-P, and LP-IR scores dropped by half or more from his last testing 6 mos. ago–imagine what a 30-day fast would do for him!

    He only lost 3 lbs. during the fast, but the INCHES…he had to have more holes added to the inside of his belts, and the belts themselves shortened.

    I don’t think he’s up for a 30-day fast. It took all his will to complete 2 weeks. I think we may (once again) follow Jimmy Moore’s idea of fasting for a week, going off it for 24 hrs., then getting right back on for another week. Jimmy led us to this place and fasting in general, so I’m sticking with what sounds (and sometimes works) good.

    We may also throw in a short water-only fast (over a weekend). I’m certain that will just about do him in. We’ve discussed it, and he’s got his own ideas and info (from where, I don’t know) that a water-only fast is dangerous, and is against even a measly N=1 experiment. I think he’s just a food addict, and unwilling to try. For that, I’ll go first, so he can see what happens.

  21. Dr. Fung,
    Another lovely post!
    A question – if fasting is releasing cortisol which is also a big factor in creating/contributing to obesity. Isn’t more fasting equals more cortisol and that means resistance to our anti obesity efforts?

  22. for me the dawn phenonmena was a circadian mismatch….I used to skip breakfast and eat lunch dinner but on lowcarb blood sugars in am were 7 to 8…….skipping dinner and eating a big breakfast low carb and a second meal before 4… waking blood sugars are 5 to 6…..also I found eating 30 minutes of sunrise and then a walk to get my eye clock tuned to morning uv entrained my master clock with my food clock

  23. Samir :

    While we await response from Dr.Fung Please read following details on Cortisol :

    Cortisol is both fat storing and fat releasing.

    It is fat storing because like insulin it increases the activity of the major fat storing enzyme lipoprotein lipase (LPL).
    It is fat burning because it increases the activity of the major fat burning enzyme hormone sensitive lipase (HSL).
    I always like to point out that the major fat burning enzyme in our body is called HORMONE sensitive lipase and not CALORIE sensitive lipase. This sort of gives a hint that both calories and hormones are important in fat loss.
    HSL is more accurately described as a fat releasing enzyme rather than a fat burning enzyme. This is because the fat it releases still needs to be burned elsewhere in the body otherwise it risks being “re-stored”.
    Acute elevations in cortisol help burn fat.
    Excess prolonged elevations in cortisol may cause changes in sympathetic neurons leading to increased NPY production. NPY released from peripheral sympathetic neurons stimulate fat cell growth. (Want more details on this? See this BLOG & this STUDY.)
    Chronic elevations in cortisol, especially in absence of the muscle building or maintaining hormones, can lead to muscle loss.

    Here is the link :

  24. Stancy Parsons

    Hi Dr Fung

    I have a moderately fatty liver, and I am concerned that fasting or rapid weight loss would put extra stress on it. Should I be concerned?

    My fasting blood sugar is 6, I’m about 45 pounds overweight, 50 years of age and mildly elevated liver enzyme’s and moderate fatty liver.

    Thank you for any feedback you may have.


    • Stancy

      I’m not a doctor!

      If your liver is moderately fat is because it has been working hard converting something (sugars, alcohol…?) into fat (and could not get rid of it fast enough). Now if you fast and/or do a very low carbohydrate diet, the liver will work, not so hard, converting proteins and other precursors into sugar(glucose) using liver and other fats as its primary fuel (for this and all of its other tasks).
      At least it is as I understand it


    • Stancy, when you fast, you preferentially burn fat from your liver and pancreas. That’s a large reason why fasting causes a reduction in insulin resistance. If anything, you should see an almost immediate improvement in your liver enzymes.

  25. My assumption is that Dawn Phenomenon can be different for different people. It may depend on when you sleep.

    Based on my blood Glucose changes, I saw this happening after — Time to bed + 7 hours and it stayed for 3 hours.

    Further, my BG was lesser with sleep hours >=6.

    • Saskoder

      I agree with your assumptions. In my case I have seen my morning -Fasting Blood Sugar readings varies with the duration of sleep & quality of sleep & also with the time to bed as to match the release of Cortisol & growth hormone level .The blood sugar stays high around three hours & after that it starts declining. Now these high numbers of FSB ruins my total A1C score & in order to bring this numbers down in the morning before 3 hours…I skip breakfast & take only tea with little cream & exercise for half an hour which helps me to maintain my blood sugar between 4 & 6 through out day till my dinnertime. In my case I have seen with regular fasting for three months my FSB numbers has gone down & its continue to do so. I think longer one has TYPE 2 longer it takes. Matter of persistence & determination to fight.

  26. Hi Dr Fung. So does the a1c get affected? With the higher blood sugar because of somogi or dp does it push the a1c up?

  27. Dr Fung, have you seen this study? What are your thoughts?

    While diabetes can bring with it a host of problems, one of the most dangerous is the infection that can occur in the hands and feet of people with uncontrolled diabetes. High blood sugar can start a process that ends in the destruction of the body’s infection-controllers. Researchers at Case Western Reserve University have been investigating this problem in hopes of finding more effective ways to treat these infections.

    The researchers found that as blood sugar rises, it begins to release harmful molecules called dicarbonyls, which result from the breakdown of glucose. These dicarbonyls interfere with beta-defensins (which are antimicrobial peptides) by making it harder for them to fend off inflammation and infection. In their research, they found that beta-defensins exposed to dicarbonyls had a much harder time fighting off bacteria. In fact, in a petri dish, the exposed beta-defensin’s ability to kill bacteria dropped by 50%.

    Not only do healthy beta-defensins fight off invaders, such as bacteria and viruses, they also warn the immune system that there’s a problem. But again, when they were exposed to dicarbonyls, their ability to do this job dropped significantly.

    These findings could help in the future development of new antimicrobial peptide treatments to help supplement the beta-defensins that are being blocked by dicarbonyls. Researcher Janna Kiselar, PhD, notes, “Our in vitro findings alone could have a significant impact on the development of more effective antimicrobial treatment strategies for patients with uncontrolled diabetes. The findings also emphasize the importance of lowering high blood sugar and keeping it under control.”

    The researchers are hoping to continue their investigations in animal models and human tissue. They also want to know if dicarbonyl is affecting other types of cells in addition to the beta-defensins. Researcher Wesley Williams, PhD, notes, “The body does have defense mechanisms against molecules such as dicarbonyl, but with a chronic disease such as diabetes, the effectiveness of these defense mechanisms responsible for keeping dicarbonyl levels under control may be overwhelmed. The result may be dicarbonyl accumulation that could eventually overwhelm the ability of beta-defensins to effectively control inflammation and infection.”

  28. ZenEngineer

    Dr. Fung,
    Would it help clarify the diabetes diagnosis and care debate if T2D was renamed to something other than Diabetes? T1 patients need insulin shots to live. Hyperinsulin patients should not be given more insulin, but they are treated as if they are T1 patients.

  29. Zen Engineer-

    You may wish to study the latest news on Long Acting Insulin therapy for TYPE 2 as well. Here is the link :

    FDA Approves Basaglar® (insulin glargine injection), a Long-Acting Insulin Treatment

    BASAGLAR is indicated to control high blood sugar in adults and children with type 1 diabetes and adults with type 2 diabetes.

    • ZenEngineer

      OK. So instead of controlling hyperinsulimia, insulin resistance, and resulting high blood glucose through diet and fasting, you want us to take more medicine? Do you work for Eli Lilly?

  30. […] is not working properly. But in actuality, the problem is that the liver is rejecting the sugar (see last post) because it is already […]

  31. Dr. Fung – your way of writing, your perspective, is very easy to understand. Thanks for doing what you do and giving this information to us who are still “standing in the road at night like a Deer in the headlights!” and trying to figure things out. This post really helped me understand the DP.
    Best regards to you and [please] keep writing! Thanks again!

  32. for me I got rid of dawn phen by eating a big breakfast at the same time getting my morning light setting my peripheral and main circadian clocks…..

  33. I had been trying to figure out the puzzle as well. Blood sugar high, but if you eat you will have too much insulin in the blood. If you are insulin resistant, then blood sugar will rise more, because you are resistant. Especially if you eat the wrong thing. It was such a puzzle to me. I would always think back to what I had eaten when my numbers were good. It was either I hadn’t eaten at all, or it was related to full fat. The problem I find with the vicious cycle is that I was diagnosed with hypertension. I was prescribed a beta blocker without having my blood tested. Next came the headaches. Little did I know that beta blockers causes your blood sugars to go up. Cholesterol also became skewed. Triglycerides were high as well. You guessed it. Beta blocker!!. Well now I have to take a statin to control cholesterol. But blood sugar keeps going up. Not to mention I have a hormonal imbalance with menopause. So I said all this to say this. Thanks Dr. Fung for clarifying what is actually going on in the bodies. I know we are all different, but the concept applies to all. Diabetes is a dietary issue. It goes undiagnosed for so long for some people. I had to tell my Dr I was insulin resistant. FBG was slightly higher, but until he ran my A1c, that told the true reading. So I beg individuals stop eating the junk out there, and know your numbers!!

  34. This article and subsequent forum comments are very interesting and informative. MY wife (64) had T2D diagnosed 12 years ago and was taking both Metformin and Insulin until two years ago. We then moved to a strong Carb reduced diet and within ten days she needed no medicine at all. We both lost above 10 kilos in weight since then and both feel fitter and active. However Since a couple of weeks, my wife appears to be suffering from Dawn Phenomenenon, with much higher blood sugar levels in the mornings. This seems strange after 2 years of controlled carb-intake or does anyone know if it is a sort of delayed reaction? Going on what Dr. Fung states, she needs to burn-off the excess sugar in the liver but is it possible to still have excess sugar after such a time? Since a week we have been ´half-fasting´- strongl reducing the food intake during the daytime up until the evening meal. This has had no effect on the morning blood values yet. Any suggestion or comments would be most helpful.

  35. Patrick Foo

    Dr. Fung, I am on LCHF Diet, and please advise shalI I stop taking metformin to alow
    My overstuffed liver to deflate ?

  36. Thank you for this excellent explanation of the DP, Dr Fung. I am borderline T2D (no meds) and have always been frustrated by my high (for me) am level of 100+/-. Now I understand. Am trying a 5-7 day (hopefully) fast not.

    Thank you for all you do for us! You have a great way of explaining things.

  37. I must have dawn phenomenon at times. My fasting glucose at 5:00 AM can get into the 90’s or even over 100 at times. But if I test at 7:00 – 8:00 AM while still fasted it is low 80’s or in the 70’s.

    I do have a body clock set to get up to workout early in the morning (6:00 AM workout). Can my cortisol and adrenaline levels which are geared to get me going to face an early workout be the reason my levels can get this high? Sometimes my 5:00 AM glucose level can be in the 80’s but the higher levels are happening more often. Should I be concerned?

  38. “However when you have T2D, there is too much sugar released from the liver which shows up in the blood like an uninvited guest.’This is a ‘placebo’ line. It serves no purpose but it makes us feel good.’

    Is this a bad thing? No, not at all. We are merely moving the sugar from the liver out into the blood. Lots of doctors consider it bad, because they are only concerned about the sugar that they see (in the blood). They do not concern themselves with the sugar that is hidden away.”

    Please can anybody tell me how the shifting of sugar from the liver into the blood will affect our HbA1c results? I have been doing IF for 16+ hours on a fairly regular basis to both lose weight and lower my BG and I do experience the dawn phenomenen and have waking results of between 7 -8. My HbA1c results have reduced from 55 to 38 over the last 9 months, but I’m concerned that they may increase at the next check?

  39. Are there any specific lab results which would indicate that the liver is in fact full of sugar? enzymes or anything else to help verify the DP?

  40. […] Dr. Jason Fung: This is similar to the Dawn Phenomenon, Read my post here – […]

  41. […] my body had higher levels of sugar than when I do eat – how is that possible? (textbook case of Dawn Phenomenon). By December 12th it seemed useless – I reserved myself to the fact I needed medication to […]

  42. Richard Burris

    I have been doing fasting from 8pm to noon the next day for at least 6 or more months. My fasting morning BG is around 200-250 everyday. I do try to use LC diet but LCHF is hard for me and I do eat some carbs, but the noon to 8 pm window has helped my neuropathy in my right foot a lot. I was diagnosed t2d at age 39 and I’m 55 now. I use 500 mg Glucophage at night and one in the morning, I tried 1000 mg twice a day but saw no improvement in BG. I see now that my liver is dumping sugars and BG is higher if I ate carbs and liver dumped old sugar and newly put in sugar too. It’s tough to eat LCHF all the time, can I just do longer fasts and see better BG results? I find fasting hard too if longer than 16 hours, especially since I work a physically active job. I take Serrapeptase to keep arteries clear and it cleared out a pain I had in my left arm too. I take 5mg Bystolic beta blocker and it helps with BP, ED and anxiety. Also taking Losartin Potassium for BP. The Bystolic helped ED some, but I’ve seen tremendous improvement by the fasting 16 hours each day, so I know I’m improving, just have not seen BG go lower.

  43. If I am understanding this post correctly, a prediabetic or type 2 diabetic whose high fasting glucose never comes down before the end off a fast is simply not exhausting their glycogen store in the liver.

    If this premise is true, then wouldn’t it make sense to test this by extending the fast, to see at what point in time glycogen exhausts? Within an hour of glycogen exhaustion, you would expect to see glucose go down from an elevated range to something more like normal, and ketones should rise at the same time? Is that something Dr Fung could clarify for us?

    One thing Dr Fung does not talk about much is autophagy, which to me is a key benefit of fasting. Does anyone know if autophagy only starts at a high level *after* glycogen in the liver is exhausted? If autophagy does not start up until after you exhaust glycogen, and if you go 16 hours with high fasting glucose, then likely you are not getting much of the benefit from the fast.

    Final question: are there any good studies that have time graphs for type 2 and prediabetics that show – hour by hour – how each of these metabolites change in the first 48 hours of the fast?

    * insulin
    * glucose
    * free fatty acids
    * ketones
    * cortisol
    * growth hormone

    I have seen these kinds of graphs for day-by-day activity in a two week or one month fast, but I have not seen it broken down by hour. What I am trying to understand is how common it is for glycogen to not exhaust in the first 16 hours of a fast.

    • I went 20 hours into a fast and at about 18 hours my high fasting glucose dropped from around 110 to 85. So I am guessing that this is the place I hit glycogen exhaustion.

      Unfortunately, as soon as I got to this point I became incredibly weak. My ketones were starting to rise but that did not feel the same as carbs. The weakness continued well into the next day and I’m still trying to recover my baseline in energy.

      I still very much want to see a study with time graphs that show the metabolites I list in my last post, hour by hour for the first 48 hours of the fast. Ultimately I might want to get blood testing done to compare my metabolites against the study to see if my body is responding in the standard way. Maybe my ketone production is not adequate to my energy needs?

      I am thin/lean so I am interested in fasting for the autophagy more than the weight loss.

  44. Richard B


    You make some interesting points. I don’t understand why my BG never seems to go lower. I was wondering too if Metformin or Glucophage is correct to take if dumping the liver is the desired effect. Maybe I’ll do longer fasts on my days off, when I’m less active. I am not thin, I weigh about 220 lbs and 190 – 200 would be more ideal for my height. My great uncle died at age 59, diabetic and almost blind, and my grandfather and mother had diabetes too, my mom with clogged arteries and finally stints put in, although the blood thinner caused strokes and her death. I want good health back and it’s very well worth the effort to fast. I need to study the IDM program better and get Dr on board too with the information on it. Last Dr I had wanted me on a statin drug, which I want off all of them, not take more drugs.

  45. […] Between Nov 19 and Dec 12, I followed a diet using the Canadian Food Guide. As I continued testing, I found my day time glucose readings were marginally improving, but my night and morning readings were seriously in the “RED” zone. I couldn’t understand – I’m not eating and my body had higher levels of sugar than when I do eat – how is that possible? (Textbook case of Dawn Phenomenon.) […]

  46. I have the Dawn Phenomenon (172 the morning after a 24 hr fast) and I wonder if it is better to continue the fast at that point, or to eat some small amount of protein which, according to some theories, will “give the liver something else to do” and interrupt the hours of DP.

    If I don’t interrupt the DP, my BG will remain elevated for several more hours. I’d like to fast as much as possible to try to heal my IR (diagnosed with T2 more than 15 yrs ago, no meds, but not controlling it well).

    Even if the focus should be on treating the IR and not just the elevated BG, I am concerned about letting BG remain elevated for so many hours before it starts to come down on its own.

    Is it Dr. Fung’s position that the elevated BG during the DP hours should or should not be treated in some way? For example, by interrupting the process, eating a small amount of protein, which according to some theories, “gives the liver something else to do.”

    • I do weight lifting in the morning after wake of up. It drastically drop my bs

  47. Ok great, but how about continuing on and complete the article with how to get this eccess sugar out out of the liver and keep it down to eliminate the dawn phenomenon in people who are not level 2 , folks who have normal daily sugar levels other than the phenomenon.
    If any one knows where I can read about this it would be appreciated.
    Thank you.

  48. N C Pathak

    I am interested to learn more

  49. N C Pathak

    I have been diabetic type2 for last 15 years and under near control with LCHF diet.
    Would like to learn more so that I can be free of diabetes and drug free.

  50. Nc Pathak
    Go to the dietdoctor website

  51. dr Fung this is an incredible article.
    taking metaformin with dinner 1000 mg
    My question is :
    Does metaformin unables the liver to dump the overload sugar while sleeping?
    Should metaformin be stopped?
    To me is contradicting the intermitent fasting then taking metaformin.
    Correct me if I’m wrong.

  52. This finally explained the dawn phenomenon for me. It could also explain early waking insomnia problems, which I have had for years. The early waking occurs at or around 4 a.m., i.e. exactly the time the hormonal rush kicks in. I would guess that this is exacerbated by high cortisol levels caused by PTSD from early childhood experiences, creating a vicious circle.

    I am borderline pre-diabetic and working with the information in your book to counteract it. After just a week my dawn blood sugar has dropped from 125 to around 110, and it falls to below 100 in the course of the morning.

    In my current regimen I’m doing a daily intermittent fast of around 18-20 hours by skipping breakfast, which is absolutely fine for me, and eating lunch and dinner at around 3 and 8 pm. Also eliminating sugar and other refined carbs, of course. This works well for me, because if I don’t eat in the evening I have sleep problems.

  53. […] the lower ketone levels in the morning, a nice redditor pointed me over to an article about the Dawn Phenomenon. That article was really cool and explained a lot, I also found a bunch of outer really interesting […]

  54. Thanks Dr. Fung for all your work. I have been eating LCHF since June 1, 2016 and doing intermittent fasting. My numbers are higher in the morning and they are great the rest of the day. Have added walking three times a week on the treadmill for an hour at the Y. I was went to bed with 82 reading and woke up to 102 this morning. Was so discouraged, but your article gave me comfort to know that until my liver gets itself straightened out this is normal for me. I am okay with that. I know I need to lose about 70 more lbs. and I have lost 51 so far. Posting this link on my blog so others will have comfort too. Blessings!

    • May be simple physical activity before measurement will work for you too.
      That is how i keep my BG low. See my post for details. Cheers, Victor

  55. Does this mean that the Fast Diet is not healthy for Type 2 Diabetics – fasting 2 days a week?

  56. I am really trying to do a ketogenic diet and can’t get my fasting BS under control. most of the day I sit in the 7-8 range but my fasting is between 9-12 everyday. I have read that I should be taking vinegar and cheese about 1:00 AM to help fight this (its not helping), but based on reading this, is the suggestion just to let it happen, since it is emptying the liver of the excess stores? I am also trying to fast 24-36 hours 2 or 3 times/week. Thanks.

  57. I have new BG data on my PIR (I hope its just PIR and not some strange illness). As many of you, I wake up with 90-105 mg/dl FBG. When I start to move around (some stairs) etc., my BG
    drops to ~80-85 in 20-30 minutes. If i choose to do light exercise (push ups, sit ups )I can easily drop my BG to 60-70 depending on exercise intensity. All this without eating in fasted state (I do not do breakfast).
    However, if I stop be active and lay down or sit down in front of computer for ~30 minutes, my BG builds up back to 90-95. Same things later at work- after working/sitting BG aroung 90-95. Moving and walking brings it down 80-85. Getting more intensity bring it down to 65-75. Getting back to the chair for 30 min gets me back to 95. Similar picture after eating, activity bring down whole BG profile by ~10 points.
    I am in mild ketosis 0.3 mmol/l in the morning and it slowly builds up to 0.8 in the evening. My ketones do not react to these wild BG swings at all. My HbA1c is 5.1%. Fasting insulin was 4.8 last time measured (2 month ago). I lost 25 pounds in 18 months by eating 1500 Cal (20-30 grams of carbs,~80 grams of proteine). Current weight-170lb, height 174 cm. Feel good, not starving at all, sleep well. Walk 5 miles everyday, with HIIT 2 days a week.
    I am observing this pattern for 3 months now, since the moment I discovered it. It is very consistent. I wander if glycogen shortage is doing this to me, since I have a little buffer and body taps directly in to BG for its urgent needs and then slowly restores BG back?

  58. […] As soon (as) insulin falls, sugar comes rushing out of the liver and into the blood. […]

  59. I am finding the morning bg a bit worrisome. I started intemitten fasting about a month ago and ketogenics. I am off metformin since nov. 6th. What has me worried is each morning my bs is higher. I understand this dawn response but now It seems that each morning my bs is getting higher and higher. Today 7.2 so my question is why is it getting progressively higher? It does drop as the day goes on but I fast to get it down. Would that be a mistake? Also I havent lost a pound at all.

  60. Dr. Fung

    Im 30 yrs old and was diagnosed with diabetes in Jan ’16. I was to do a shoulder surgery and the previous night during blood work my sugar readings were 595mg/dl. I told them there must be a problem with the glucometer. Two more devices showed readings of 550 mg+. So i was asked to bring down my sugar levels for them to consider performing the surgery. The hospital suggested I start insulin but I refused because My dad passed away because of renal failure, due to diabetes and we were somewhat late in learning that IF and LCHF could help (since his kidneys had already given in). He would take over 100 units of insulin a day and I didnt want to go down that path. Alos, a friend told me that he heard of someone reversing their diabetes through a keto diet and I thought he was MAD!

    I spent the next two weeks on a strict diet and metformin (half tab in the morning), which was good enough to perform the surgery. I’ve had decent glucose levels (under 120 – fasting and under 180 – 1 to 2 hrs post meal) post surgery and stopped metformin as by lunch time I would have very low blood sugar level causing cold sweats.

    Since the last few months i’ve subscribed to dietdoctor and have been following the 16:8 IF lifestyle. I’ve lost over 15 kilos since Aug ’16 but during this period I ate a lot of rice based meals (biryani). In India it is very hard to find a meal without rice, wheat or pulses. So while i lost weight, my blood sugar levels had been extremely volatile going upto 400mg/dl levels at times. I am trying self management of my diabetes because talking to any physician or diabetologist here in Bangalore doesnt help as they are all pro-insulin + metformin.

    So after some research, I came across the LCHF diet and since i’ve started it im amazed at how my blood sugar is stabilized. ~8 days ago I had a reading of 123 mg/dl post dinner which I havent seen in months and this has continued until today. It’s 4pm IST and I just had my first meal (a cheese omlette with 4 eggs and some veggies) and my reading was 170 mg/dl and 153 mg/dl 30 mins later. This may still be high, but given my history this is improvement.

    Now, All this is great. I’m changing my lifestyle and am enjoying it. However, what puzzles me is my morning blood sugar. Since the last 8 days they have been between 280 – 374 mg/dl. This morning was 308 mg/dl.

    I just read your article on the “Dawn Phenomenon”, is it safe to assume that its just that or is there something im not undertsanding fully about the morning blood sugars?

  61. […] the rest of the body. To be honest, the causes of the dawn phenomenon are not fully elucidated, and experts give varying explanations. But the fact is that many people who eat low-carb report […]

  62. Dr. Fung.. Appreciate all your podcasts and your book Obesity Code.
    I am pre-diabetic with current AC1 at 6.1
    My blood Sugar levels during the day range from 60- 99. But my morning fast is from 122-129. I started a LCHF eating lifestyle about 5 weeks ago. I eat 25 or less carbs a day. In 5 weeks I have lost close to 25 lbs. I walk every day and I go to the gym 3-4 days a week when I bike for 30 minutes, then do leg strengthen exercises (3) at 225 reps ea., and lastly do abs crushes for 225 reps.
    I am on Blood Pressure pills calcium blocker, and lipitor generic.
    I am also planning on beginning a Intermittent
    Fasting 24 hours twice a week.
    My questions:
    1. Can I expect my Morning Fasting Blood Sugar to continue to be high (122+) if so for how long?
    I will be on LCHF + 24 hour fasts 2 times week.
    2. What type of fasting is recommended and what withdrawals can I expect over what period of time? Will I get the shakes or be weak or sick? Will this last for 2 or three fasting sessions? Just need an idea.

    Any help answering my questions would be appreciated!

  63. How does Leptin hormone come into play with Insulin ?? I thought Leptin was the key hormone to allow fat loss.. Can you clarify?


  64. Follow up to my high fasting morning numbers of 122-129.
    Now with continued low carb diet by my morning BS ranges from 85-110.
    I recently had a 110 reading at morning fast.. I decided to not eat and continue to fast for 2 hours. I retook my BS after continued morning fast and it was a normal 85.
    Looks like Dawn Phenomenon is physlogical and maybe normal once your body adjusts.

  65. seeni ambalam

    Hi Doc,
    This is the first really sensible article about dawn phenomenon that I have read. Thank you.

  66. christie barnett

    Dr Fung, what do you think about Chris Kressers comments about IF and blood sugar?
    Thank you

    Intermittent fasting, cortisol and blood sugar
    on NOVEMBER 17, 2010 by CHRIS KRESSER 230 comments
    There’s been a lot of discussion about the benefits of intermittent fasting (IF) in the paleo community lately. Paul Jaminet mentions it’s role in boosting the immune system in his book, The Perfect Health Diet, and IF can also be helpful for those trying to lose weight and tune their metabolism.

    From an evolutionary perspective, intermittent fasting was probably the normal state of affairs. There were no grocery stores, restaurants or convenience stores, and food was not nearly as readily available or easy to come by as it is today. Nor were there watches, schedules, lunch breaks or the kind of structure and routine we have in the modern world. This means it’s likely that our paleo ancestors often did go 12-16 hours between meals on a regular basis, and perhaps had full days when they ate lightly or didn’t eat at all.

    So, while I agree that IF is part of our heritage, and that it can be helpful in certain situations, I don’t believe it’s an appropriate strategy for everyone.

    Why? Because fasting can elevate cortisol levels. One of cortisol’s effects is that it raises blood sugar. So, in someone with blood sugar regulation issues, fasting can actually make them worse.

    I’ve seen this time and time again with my patients. Almost all of my patients have blood sugar imbalances. And it’s usually not as simple as “high blood sugar” or “low blood sugar”. They often have a combination of both (reactive hypoglycemia), or strange blood sugar patterns that, on the surface, don’t make much sense. These folks aren’t eating a Standard American Diet. Most of them are already on a paleo-type or low-carb diet. Yet they still have blood sugar issues.

    In these cases, cortisol dysregulation is almost always the culprit. When these patients try intermittent fasting, their blood sugar control gets worse. I will see fasting blood sugar readings in the 90s and even low 100s, in spite of the fact that they are eating a low-carb, paleo-type diet.

    That’s why I don’t recommend intermittent fasting for people with blood sugar regulation problems. Instead, I suggest that they eat every 2-3 hours. This helps to maintain stable blood sugar throughout the day and prevents cortisol and other stress hormones like epinephrine and norepinephrine from getting involved. When my patients that have been fasting and experiencing high blood sugar readings switch to eating this way, their blood sugar numbers almost always normalize.

    I don’t think eating every 2-3 hours is “normal” from an evolutionary perspective. But neither is driving in traffic, worrying about your 401k, or staying up until 2:00am on Facebook. The paleo template is there to guide us, but it’s not a set of rules to be followed blindly. This should also be a reminder that there’s no “one size fits all” approach when it comes to healthcare. Successful treatment depends on identifying the underlying mechanisms for each individual and addressing them accordingly.

  67. I have been following a strict organic LCHF/Keto diet for 10 months now….Diagnosed via HBA1c as T2 in April 2016 with a reading of 63, reduced to 40 (Normal) by September 2016. Last HBA1C in Feb 2017 was 41, so it has increased slightly. I weight train 3 times per week for approximately 1 hour each time. Body fat reduced from 19% to 16 % and weight normal (BMI 23). I am not overweight or have visceral fat and consider my physique in excellent shape, so I am at a loss as to why my blood glucose readings are normal throughout the day (4.5 – 5.7) but spike in the morning to around 6.7.

    Could the weight training be causing an increase in growth hormone as I am “muscle building”. I have introduced protein shakes, but I use grass fed whey isolate (no additives at all) other than cacao powder, chia seeds, flax seeds, 1/2 banana, organic peanut butter, coconut oil, some blueberries……but these do not cause spikes as my glucose reading is around 4.5-5.2 after ingesting…I am at a loss as I thought I had nailed it – got a letter from doc saying I was in “remission”. However, I am concerned my morning readings are higher and that’s when blood is usually taken for my HBA1C – Blood always taken in morning after fasting.

    • Get rid of cocoa powder, eat fruits sparingly, fruits must be eaten when ripe to break down the complex sugar into simple sugar. That’s healthier for you but drops you out of ketosis quickly. You can be building muscle due to the carb loading with ur post work out shakes, which is anti ketogenic. I’d switch to Brazil nuts instead of peanuts because peanuts have a lot of protein to fat, if not equal ratio. This doesn’t help you, Brazil nuts by the cup have 80grams fat maybe 16-20g protein, 4carbs? Protein isn’t important over 12% how long are your fasts? I’ve gone 7days water fast a few times, but always broke with massive Nutella and other foods right around the 7th day for some reason. Chocolate and cheese always my kryptonite with ketosis. 🙁 but if your glucagon is up then why is ur blood sugar up?

      However how long are ur fasts? And what are your daily macros on non fasting days on lchf? I’d like to know

  68. Doing Ketogenic woe for three months with no cheats at all and cutting out dairy and nuts, I still have a high fasting glucose and an early morning high glucose count. To me, the definition of high is 114 because I literally feel horrible, have a hard time functioning and I can tell my blood sugar is elevated. I feel very much like I would if I was hypoglycemic but I do not have a low count but a relatively high one. I have lost 3 pounds in three months. I am not diabetic according to my ac1 but I do believe I have high triglycerides and PCOS, insulin resistance. I do not drink alcohol and I am not sure what I can cut out of my diet at this point. I am eating healthy fats by way of fatty animal meat, butter from grass feed beef, avocados and green veggies. When I did a 24 hour fast I gained 3 lbs and my glucose was a little higher than normal but under 100. By eating Keto, I know I am healthier because inflammation is gone but something is still not balanced and I am not sure what to do about it. Is it possible as a non diabetic that I am becoming hypoglycemic in the night which is causing my sugar to elevate in the morning?

    • Susan T

      Laura C, have you learned anything to help you early morning high BG readings? I too have been on ketogenic woe since end of March. I’ve lost 11.5 pounds but have been stalled for 2 weeks now. I skip breakfast so I do IF 14-16 hours daily.
      I know that I am insulin resistant and have slightly high triglycerides.

  69. Linda Creatore

    Hi Dr. Fung…I am T2 with high BGs (110 to 180)…should I let my high morning BG keep going up (which it will) and NOT take my metformin? It seems from the above article that my liver needs to dump all the toxic sugar build up in order to heal. Does taking metformin stop or hinder this process. The article did not address this question of whether or not to take meds in morning to counteract the morning high BG.

    If you can, please address this…it would really help to make me a little less anxious about letting my BG continue to rise until it, hopefully, will start to go down. I’m not sure I’ve ever simply let it go long enough to test when/if it comes down, without first taking some meds. A little scary if not well informed/educated.


  70. Susan T

    Dr. Fung, Thank you for your work in trying to reverse the root problem instead of just treating symptoms like most of the doctors I have seen. I am 55 and been obese the biggest part of my life while trying many diets and even gastric surgery. I found LCHF way of eating 2 months ago and have been doing this as well as intermittent fasting daily for 14-16 hours. I have high BG readings in the morning…125-145. I had a loss of 11.5 lbs in first 3-4 weeks, but am stalled at this point. I have high triglycerides and been diagnosed with fibromyalgia. I want to do what I need to do to get my morning BG to come down. I realize this could take some time, but I was wondering if there is something more at this point I need to do to begin to see the morning BG readings go down and get into Ketosis to begin to loose more weight. I need to loose 140-145 pounds. Thank you!

  71. Daryl Roberts

    Dr. Fung, I just came across this site today, really impressed. I just turned 61 yesterday, my last A1C was in March, was 6.1 so the threat of a diagnosis of diabetes is looming. My mom was T2D, diagnosed in her mid 60’s. I’ve been chronically about 10-15lbs overweight for yrs (ie, 198) have had gotten weight down closer to ideal a couple times (around 185) but gain 1/2 or more back. Also tried to get into ketosis, got a Nova test kit, but even on low carb diet I seemed to be unable to get into ketosis. But recently, I’ve been interested in intermittent fasting, have done 3 now in the last 8-10 weeks, in the middle of a 3day fast with just vegetable juice (greens only) & I’m down 7-8 lbs, & I just got a BOHB reading of 1.3, so I guess I’m in ketosis. But I also took my glucose & it was 130. I’ve also started taking Berberine & Gynostemma, & although I suspended all supplements for the fast, I decided to take those today, haven’t retested to see if they made an immediate effect. So I’m in a paradoxical condition, high fasting glucose and ketosis. I’m interpreting that to mean the liver is “dumping” glycogen, divesting the fatty liver stores, as you describe. Do you have any observations or concerns about this situation?

  72. I’m so glad I came across this article. I could not understand why my “fasting” blood glucose was always the highest of all readings. I alaways thought First readings in the morning should be lowest. Thank you Dr. Fung. Very well explained.

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