Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
27 Jun

The Definitive Guide to Insulin, Blood Sugar & Type 2 Diabetes (and you’ll understand it)


We all know by now that type 2 diabetes is an epidemic. We’re seeing words like crisis and runaway all over the news and in the journals. Heart disease rates have been cut in half since the staggering margarine days of the 1980s, but diabetes has swiftly risen to fill that gaping void and meet the challenge of Completely Unnecessary Disease Epidemic.

Here’s my ultra-simple explanation of the entire insulin/blood sugar/type 2 diabetes mess. Big Agra could really care less about you. That’s just business. The pharmaceutical industry is not in it for the love of life. If that were the case, drugs would be much cheaper. The FDA has to think about public health, but it also has to think about treading carefully on the toes of corporate interests, because that’s how it works when you’re the biggest economy in the world.

Print this explanation out, stick it on your fridge, email it to your aunt. And put down the pasta.

When you eat food, the body digests the macronutrients: carbohydrates, proteins – actually many different amino acids – and fats. (Anything it can’t digest, like alcohol or fiber or toxins, either passes right on through or, if it makes it into the bloodstream, gets filtered by your liver, a beast of an organ if there ever was one.) We measure these macronutrients in grams and calories, but your body operates in terms of fuel. If you eat more fuel than your body needs – which most people do – the body is forced to store this excess. This ability to store excess fuel was an evolutionary imperative in a world that was in a state of constant “feast or famine” 50,000 years ago. In terms of Primal Health and our DNA blueprint, humans became very efficient fuel storage specialists and were able to survive the rigors of a hostile environment and pass those very same genes down to you and me. Thanks a lot, Grok!

Bear in mind that every type of carbohydrate you eat is eventually converted to a simple form of sugar known as glucose, either directly in the gut or after a brief visit to the liver. The truth is, all the bread, pasta, cereal, potatoes, rice (stop me when you’ve had enough), fruit, dessert, candy, and sodas you eat and drink eventually wind up as glucose. While glucose is a fuel, it is actually quite toxic in excess amounts unless it is being burned inside your cells, so the body has evolved an elegant way of getting it out of the bloodstream quickly and storing it in those cells.

It does this by having the liver and the muscles store some of the excess glucose as glycogen. That’s the muscle fuel that hard anaerobic exercise requires. Specialized beta cells in your pancreas sense the abundance of glucose in the bloodstream after a meal and secrete insulin, a peptide hormone whose job it is to allow glucose (and fats and amino acids) to gain access to the interior of muscle and liver cells.

But here’s the catch: once those cells are full, as they are almost all the time with inactive people, the rest of the glucose is converted to fat. Saturated fat.

Insulin was one of the first hormones to evolve in living things. Virtually all animals secrete insulin as a means of storing excess nutrients. It makes perfect sense that in a world where food was often scarce or non-existent for long periods of time, our bodies would become so incredibly efficient. How ironic, though, that it’s not fat that gets stored as fat – it’s sugar. And that’s where insulin insensitivity and this whole type 2 diabetes issue get confusing for most people, including your very own government.

If we go back 10,000 or more years, we find that our ancestors had very little access to sugar – or any carbohydrates for that matter. There was some fruit here and there, a few berries, roots and shoots, but most of their carbohydrate fuel was locked inside a very fibrous matrix. In fact, some paleo-anthropologists suggest that our ancestors consumed, on average, only about 80 grams of carbohydrate a day. Compare that to the 350-600 grams a day in the typical American diet today. The rest of their diet consisted of varying degrees of fat and protein. And as fibrous (and therefore complex) as those limited carbohydrate foods were, their effect on raising insulin was minimal. In fact, there was so little carbohydrate/glucose in our ancestor’s diet that we evolved four ways of making extra glucose ourselves and only one way of getting rid of the excess we consume!

Today when we eat too many carbohydrates, the pancreas pumps out insulin exactly as the DNA blueprint tell it to (hooray pancreas!), but if the liver and muscle cells are already filled with glycogen, those cells start to become resistant to the call of insulin. The insulin “receptor sites” on the surface of those cells start to decrease in number as well as in efficiency. The term is called “down regulation.” Since the glucose can’t get into the muscle or liver cells, it remains in the bloodstream. Now the pancreas senses there’s still too much toxic glucose in the blood, so it frantically pumps out even more insulin, which causes the insulin receptors on the surface of those cells to become even more resistant, because excess insulin is also toxic! Eventually, the insulin helps the glucose finds it way into your fat cells, where it is stored as fat. Again – because it bears repeating – it’s not fat that gets stored in your fat cells – it’s sugar.

Over time, as we continue to eat high carbohydrate diets and exercise less, the degree of insulin insensitivity increases. Unless we take dramatic steps to reduce carbohydrate intake and increase exercise, we develop several problems that only get worse over time – and the drugs don’t fix it.

Ready for this? Let’s go:

1) The levels of blood glucose stay higher longer because the glucose can’t make it into the muscle cells. This toxic glucose is like sludge in the bloodstream clogging arteries, binding with proteins to form harmful AGEs (advanced glycated end-products) and causing systemic inflammation. Some of this excess glucose contributes to a rise in triglycerides, increasing risk for heart disease.

2) More sugar gets stored as fat. Since the muscle cells are getting less glycogen (because they are resistant), and since insulin inhibits the fat-burning enzyme lipase, now you can’t even burn stored fat as easily. You continue to get fatter until eventually those fat cells become resistant themselves.

3) It just gets better. Levels of insulin stay higher longer because the pancreas thinks “if a little is not working, more would be better.” Wrong. Insulin is itself very toxic at high levels, causing, among many other maladies, plaque build-up in the arteries (which is why diabetics have so much heart disease) and increasing cellular proliferation in cancers.

4) Just as insulin resistance prevents sugar from entering muscle cells, it also prevents amino acids from entering. So now you can’t build or maintain your muscles. To make matters worse, other parts of your body think there’s not enough stored sugar in the cells, so they send signals to start to cannibalizing your precious muscle tissue to make more – you guessed it – sugar! You get fatter and you lose muscle. Woo hoo!

5) Your energy level drops, which makes you hungry for more carbohydrates and less willing to exercise. You actually crave more of the poison that is killing you.

6) When your liver becomes insulin resistant, it can’t convert thyroid hormone T4 into the T3, so you get those mysterious and stubborn “thyroid problems”, which further slow your metabolism.

7) You can develop neuropathies (nerve damage) and pain in the extremities, as the damage from the excess sugar destroys nerve tissue, and you can develop retinopathy and begin to lose your eyesight. Fun.

8) Eventually, the pancreas is so darn exhausted, it can’t produce any more insulin and you wind up having to inject insulin to stay alive. Lots of it, since you are resistant. Congratulations, you have graduated to insulin-dependent Type 2 diabetes.

That’s the bad news. And it’s seriously bad. But the good news is that there is a way to avoid all this. It’s all right there in your DNA blueprint. First off, exercise does have a major impact on improving insulin sensitivity since muscles burn your stored glycogen as fuel during and after your workout. Muscles that have been exercised desperately want that glucose inside and will “up regulate” insulin receptors to speed the process. That’s one reason exercise is so critical for type 2 diabetics in regaining insulin sensitivity. It’s also the reason why endurance athletes can eat 400 or 600 grams of carbs a day and stay lean – they burn it all off and make room for more.

Resistance training seems to be as effective as aerobic activity, but a mix of the two is the best. And because you are now “insulin sensitive”, you don’t require as much insulin to store the excess, which “up regulates” all the fat burning enzymes, so you burn your stored fats at a much higher rate throughout the day. Important amino acids and other vital nutrients have access to the cells when insulin sensitivity is high, so you’re building or maintaining muscle and losing fat weight. Go team.

Second, cutting back on carbohydrates, especially the obvious sugars and refined stuff is absolutely essential. Make fresh vegetables the base of your food pyramid. I get rip-roaring furious when I see our government suggesting that we get 60% of our calories from carbohydrates. That’s ridiculous, bordering on criminal. Think about what is optimal for human health from a “primal” perspective. Look at the genetic blueprint. Look at the statistics and studies if you like – or simply observe what’s going on around you at restaurants, movie theaters and school cafeterias – and you’ll begin to understand the implications of a diet out of whack with our design. The evidence is nothing short of overwhelming: carbohydrate intake of the refined, sugary sort is enormously stressful to the body.

Not only should diabetics limit carbohydrate intake – everyone should. We are all, in an evolutionary sense, predisposed to becoming diabetic.

Mainstream opinion is, of course, partly correct in that sugar does not necessarily “cause” diabetes – increasingly, scientific evidence is showing that genetic susceptibility plays a huge role in individuals’ potential for developing diabetes. Well, no kidding! The entire mainstream argument boils down to this: sugar does not cause diabetes; it’s genetic. I couldn’t agree more. I would simply say that our shared genetic susceptibility to insulin resistance, inflammation, cardiovascular disease and obesity shows that any sort of refined sugar or grain is the last thing humans should be eating. Our genetic “primal blueprint” indicates that we are not meant to consume sugar.

Next week, I’ll be discussing cortisol, stress, and the adrenals in light of our “primal” blueprints. See you then. I welcome your comments and questions as always.

Further reading:

What I eat

My Carb Pyramid

More Primal Health columns

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You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Daniel –

    Your comment reminds me of a section in Good Calories Bad Calories that didn’t quite make sense (I’m not a scientist). Can you please provide a reference to the study involving the 400 grams of carb stuffing?

    And Mark:
    I’m new to your site and just want to congratulate you on a terrific achievement – I’ll certainly be back for more!


    Donald wrote on April 29th, 2009
  2. Hi there,

    I’ve been fighting a weight problem for the last three years, that I’m convinced was caused by an anti-depressant. No amount of exercise and healthy eating made any difference, although I did stop gaining weight when I came of the meds.

    As I’m also a woman in my mid forties, it certainly doesn’t help. Recently my menopause doc suggested I may be insulin resistant (My mum is type 2 diabetic) and I’ve been looking into insulin resistance more. That led me to looking into the part carbs play on this and I was trying to find out more about the amount of carbs I should be eating when I came across your site.

    This site is so informative I wanted to leave you a message to say thank you for providing such clear information, in real terms, not medical jargon.


    Lorrii wrote on June 24th, 2009
  3. I’m bewildered. I eat an extremely low protein diet, yet my glucose numbers are always around 98-101. Any thoughts?

    Thanks in advance!

    Jan wrote on July 14th, 2009
  4. I’m bewildered. I eat an extremely low carb, high protein diet and my glucose numbers are always around 98-101. MY A1C is 5.6. I jog at least 1 hr. 6-7 days a week. Any thoughts?

    Many thanks in advance!

    Jan wrote on July 14th, 2009
  5. 1. By “glucose numbers” do you mean fasting?
    2. Why are you jogging so much? Not a part of the primal thing. Start doing high intensity intermittent. Better results with much less time.
    3. Do you “lift heavy things occasionally”? If not, start. This is very important if you’re trying to burn sugar, especially those large muscle groups.
    I used to have blood sugar problems too. Totally solved with primal. You can do it!

    Dave, RN wrote on July 14th, 2009
  6. Yes, I learned today that my last fasting glucose was 101. Last year, it was 88. In the past, always around 98. What disturbs me is that it’s creeping up. My insulin level is well below 10…something like 4.5.

    I’m jogging so much to try and get an extra 10 pounds off that crept up after I began taking Synthroid for an underactive thyroid two years ago. I used to take Armour.

    I do moderate weight lifting (8 lb. free weights, 2 or 3 times a week for approx. 10 minutes. I just happened upon this site and am not familiar with “the primal thing.” Will start reading more.

    Right now, I’m just upset to learn that my glucose level is up to 101. It’s discouraging with all I do to optimize my health. Your support means a lot. Many thanks!

    Jan wrote on July 14th, 2009
    • I have the same problem. Ive only been primal for about 4 months and my blood work came back with fasting glucose at 109. Last Nov it was 87. I eat around 40g carbs a day and exercise (sprint, lift heavy things, walk) every day for around 30 min. I eat no dairy, no grains of any kinds, no sugars, high proteins and fats and minimal veggies/fruits and only drink water. My Doc told me to start “eating a healthy diet, exercising daily, and losing weight.”. I have been primal for 4 months and haven’t lost any weight. And even my blood pressure is high 0_0 How much more “healthy” in my eating can I get? And same for exercising? So frustrated!!

      Becky wrote on September 14th, 2010
      • Probably not good timing in my answer, but I see nobody is mentioning this: for the really insulin resistant people out there, it seems that you need to also restrict protein to a moderate amount. Part of the excess protein is converted to sugar by the liver. Look into “ketogenic diet” and the explanation behind it all.

        Izzy wrote on May 8th, 2013
  7. i think the author should focus on writing articles about running marathons instead, as this seems to be the area of his expertise…

    being a pre-med candiate with a degree in Biology is hardly enough credentials to postulate (without providing any proof) on the inner mechanics of Diabetes.

    Erhan Hosca wrote on August 2nd, 2009
    • @Erhan: an appeal to authority is not a good argument. As for proof, one can never prove a hypothesis, only disprove it. Anyway, Mark is not a lone voice in this, the web is full of papers and studies by scientists who make a convincing case, and as Mark’s work shows, the anecdotal evidence is increasing, and becoming too big to ignore.

      Gary Katch wrote on August 30th, 2009
    • I think the author (Erhan) should focus on writing comments about children’s fantasy books on the Medical Health Industry instead, as this seems to be the area of his expertise…

      I am a Type 2 now insulin dependant precisely because I didn’t have Mark’s info available to me. Instead I worked with Top Endos in Los Angeles, followed the ADAs dietary recommendations and nearly died twice with blood sugars over 800 and 700.

      Erhan, put up your own blog and become part of the solution not part of the problem.

      Andre Chimene wrote on August 21st, 2010
    • I hear you loudly and clearly Erhan:
      It simply amazes me that there is such vehement hatred of and vilanization of carbs. Being inactive is criminal not carbs. I have had type1 diabetes for over 29 yrs. I eat at least 500g carb/day and fight to maintain 139lbs with extremely low body fat. My blood sugars are superb and my insulin doses quite low. My secret is tremendous daily activity. We evolved to be extremely active not to hide from HEALTHY carbs as if they were monsters.

      It really is scary that people today are so greatly afraid of being very active that they point at whole grains and lots of fruits daily as poison. The poison is your lack of MOVEMENT. Wow… laziness…

      freethinkr wrote on February 25th, 2012
    • As the author of the beauty book soon to be released on Kindle about yeast and aging, I feel that yeast, candida, is hidden in the mix;either in its yeast form or its fungal form ,most of us are destined to be yeastie beasties and we do not even know it.

      donna wrote on March 8th, 2012
  8. “If you eat more fuel than your body needs … the body is forced to store this excess.”

    In GCBC (p.300) Taubes argues against this supposition: “Just as we decrease energy expenditure in response to caloric surplus, we will also increase expenditure in response to caloric surplus.” (He also does a good job busting the “thrifty gene” hypothesis, and the “feast or famine” idea.)

    This makes sense to me, as it demonstrates that the body regulates fat deposition; it is not forced to store the extra calories, there is the option of burning them (or even excreting them).

    The real question is why the normal up-regulation of energy does not occur in obese people.

    Gary Katch wrote on August 30th, 2009
  9. I cant belive there exist people like you who care about our health and give us informations for FREe.

    Long life Mark, you are really special man.

    Sorin wrote on August 30th, 2009
  10. This is great. After my mom and two brothers were diagnosed with Type 2 diabetes, I cut out most grains. I soon lost the 10 pounds I’d been struggling with for about 10 years. I finally feel like I’m the weight I should be. I can’t believe I fed my kids so many carbs as they were growing up. Gov’t said to. Shame on them

    Anne Fell wrote on October 28th, 2009
    • Well Anne, usually it pays to always (let me stress this ALWAYS) double-check anything the government tells you. Their interests are usually not congruent with ours (the regular folks).

      You are responsible for yourself and your family. Not the government. Regardless of what the leftist establishment tries to tell you.

      As an individual with free will it is up to you to proofread anything that’s presented to you. (This post of mine included).

      I’d like to think that most folks on this website are here because they like to think for themselves. They like to question and evaluate issues instead of just blindly following someones directives. Especially when it’s from any governmental body.

      So I’d like to applaud you for cleaning the cob webs off of your critical thinking skills! :)

      No offense was meant in typing this post. Mea culpa if I cam across a little too strong…

      lrd wrote on July 18th, 2012
  11. Question: Is there a way to reverse/or to halt the progression to Type II diabetes before you get there? If you’re at pre, initial or type I, can dietary changes help?

    If you’re already at Type II diabetes can dietery changes help?

    William wrote on December 30th, 2009
    • The answer is yes! Change your food and change your epigenetis. Epigenetics is the music your genes play. They either play the music for diabetes or health. What you eat controls the music. Bring your carbs down below 50 grams per day or less, up the beneficial fats, coconut oil, ghee, butter, Sat fats, olive oil, mono fats. Keep your protein adequate…divide your LEAN mass (you without fat) in half. If you are 100 lbs LEAN…then eat 50 grams of protein. Veggies, Beneficial Fats (lots) and some protein. You will reverse the damage by having healthy normal adult blood sugars, fasting 83 and after meals never over 130. That gives you normal insulin, leptin and better than normal health. Go get your health…it is waiting for you.

      Andre Chimene wrote on April 11th, 2013
      • Hi, does anyone know if neropathy can be reversed..My feet have been burning terrible and they put my on Nerotin..I don’t like taking any meds..does anyone know of any natural remedies?…I do control my type 2 diabetes with diet…no meds…very low carbs..Thanks

        Patti wrote on July 11th, 2013
        • I have been diabetic type 2 (insulin dependent for 5 years) and for several months I had increasing numbness/burning in my feet and toes and twitchy/ sometimes sharp little stabs of pain in my lower legs. and I felt like I had to stretch my feet a lot. ( especially in bed- kept me from sleeping.) I read about horse chestnut extract for edema lower extremeties and butchers broom for circulation. I can’t speak for anyone else but my foot /ankle edema is gone and I have had no pain/twitching in my lower legs for a few weeks now. no numbness in toes. my doctor was thrilled.
          maybe that will help you.
          my doctor was very pleased with those results and 12 lb weight loss since 1st of june. and I gave her a copy of primal blueprint and she said she would read it :) she is a md- internal medicine.
          good luck to you

          carol wrote on July 11th, 2013
        • Thank you Carol!! This burning has been horrible..have not been able to sleep.I am going to try these..thanks again!!

          Patti wrote on July 11th, 2013
        • According to Dr, Bernstein, neuropathy can be reversed, but it can take years with normal blood glucose. By normal he means an A1c between 4.2 and 4.6 with a tight average blood glucose of 85 mg/dl.

          Dr Bernstein is now 80 years old and has been living with type I since 1946. In the 70’s he had so many complications that he was not expected to live much longer. That is when he got access to a meter and started ‘eating to his meter’. His book is Diabetes Solutions.

          I was diagnosed last December and am close to meeting his requirements for normal blood glucose. Most of the symptoms that I had at diagnosis, including mild neuropathy (phantom itching on my feet), have either gone or are going.

          OldTech wrote on August 5th, 2014
  12. Question:

    The article was very informative, and sounds like very sound information. My question is that whenever I decrease my sugars too low, my bloodsugar goes up! I theorize that my Liver is somehow sensing that it’s not receiving no sugars, and pumps it into my bloodstream!

    Or if I exercise without eating enough carbs before, my sugars GOES UP!!! That’s even if my sugars are high before I start. Can anyone help with this delima????

    rose wrote on January 17th, 2010
    • Yes. You are burning sugar for fuel and not ketones. Thru metabolic momentum, you body wants to do what it has done. Up the beneficial fat, Ghee, coconut oil, grass fed butter, monos and Sat fats, cold water fatty fish, bring your carbs below 50 to kick you into ketosis. Now your body prefers to burn ketones (fats) instead of sugar. This will also calm your brain and moods down so you reduce the adrenaline output. Less chance to punch your liver into releasing stored sugars.

      Andre Chimene wrote on April 11th, 2013
  13. I thank the internet Gods for directing me to Mark’s website, especially this article. My fasting glucose is 97 and very alarmed with it. I’m trying to get pregnant but with no success for more than a year now and my ob-gyn said, it could be because of insulin resistance.

    I’m physically active, working out 45mins, 6 days/week and have totally cut out wheat/gluten, sugar, caffeine, processed food in my diet since Jan 2009. We have the diabetic genetic factor, however. I’m going for Primal living because all I’ve read here makes a lot of sense.

    Grace wrote on January 27th, 2010
  14. Dearest Mark,

    I really need your help. My mom is type 2 diabetic. She does not take care of herself! She gets sicker each day as well has a very hard time walking because her feet are so bad. Here is the problem, she drinks coffee all day long with 4 sugar in each cup. She is always eating something with chocolate. I have told her a thousand times it is killing her but i always get ” Stop harping on me. who is the mom here” she does not listen to me about how serious her surgar intake can be on her body. Please I need you to tell her in terms she can understand because she does not understand docters terms how serious her diet is. I almost need someone to scare the heck out of her to make her understand!! I love my mom with all my heart and soul and it is killing me to see her so sick when there is something she can do about it!!! Please help!!!!!!!!!!!!

    cheryl wrote on February 4th, 2010
  15. Cheryl, I’m sorry, but there’s not much I can do from where I sit. Health is about personal responsibility, and until your mom is willing to learn and make adjustments, all you can really do is lead by example, show her (and tell her) you love her and offer your support when she is ready.

    Mark Sisson wrote on February 5th, 2010
  16. i still cant understand the sugar readings everybody seems to talk 90 to 100 my accu check readind says 6.9 or 11 . or 15.5 what is correct ???????

    bernard browne wrote on March 5th, 2010
    • Bernard, to convert blood sugar from mmol/l to mg/dl multiply by 18.

      My girlfriend is diabetic and I’ve taken a some readings using her meter. I am trying to follow a low carb diet but my fasting blood sugar is around 115 but this drops to around 85 1 hour after a low carb breakfast.

      Should I be worried ? Has anyone got any ideas on reducing my fasting blood sugar? Incidentally my triglycerides are also high.

      james wrote on March 19th, 2010
  17. Wow, thank you thank you thank you for the most concise, readable, and comprehensible guide to how the whole carb/insulin thing works. It’s worth passing on to the universe.

    Robin wrote on March 26th, 2010
  18. All of you people with diabetes should check out I got rid of my diabetes by taking anti-fungals and staying on Doug’s diet.

    Sheila Coon wrote on April 16th, 2010
  19. Men with type II diabetes would do well-in addition to diet change, of course!- to verify that their testosterone levels are at or near optimal ranges-not normal, optimal. If you just google ‘low testosterone diabetes’, you’ll find all manner of articles-from, to CBS. Well-publicized link.

    Another thing to look at is cancer markers. I lost my father to cancer three years ago; He was a normal, healthy man (albeit with undiagnosed AI and celiac)with normal testosterone levels…yet by the time he was actually diagnosed with cancer, it was stage IV. Had they done a full cancer marker workup with the tests that are currently available when he was diagnosed with ‘idiopathic NIDDM’ (current meaning 2006) he might still be alive. Cancer cells have as many as 40 times the insulin receptors as normal cells, and can cause type II diabetes through that mechanism. It isn’t quite type II, but as there is no other ‘type’, that’s what it’s referred to. Dad was very active, not overweight, well-muscled, and ate a good-by these standards, even-diet. Obviously, his immune system wasn’t up to snuff, but on the outside, he wasn’t a diabetic type.

    You’ll probably have to really push for it, but the alternative is much worse.

    Laurel wrote on April 27th, 2010

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