Yes, a low-carb diet greatly lowers your insulin


Less carbs, less insulin

Is “eat less and move more” really the only thing you need to know in order to lose weight?

Why is it then that most people lose weight on an LCHF diet, even when eating until satisfied and without even any increase in exercise?

The best explanation, in a simplified version, looks like this:

Carbohydrates – > insulin – > obesity

Thus more carbohydrates lead to more insulin which leads to more fat accumulation. With more details this can be written as follows:

Too many (bad) carbohydrates – > pathologically high insulin levels – > obesity

What constitutes “too many” varies from person to person depending on sensitivity and activity level (how much carbs you burn). Intensely exercising young men can often tolerate a fair amount of carbs, while heavily overweight older individuals with diabetes can only tolerate minimal amounts without problems.

The opposite is the following:

Less carbs – > lower insulin levels – > loss of excess fat

Insulin is a fat storing hormone. And the easiest way to increase your insulin levels is to eat more carbohydrates. The easiest way to lower insulin levels is to eat fewer carbohydrates.

This seems very straight forward. But some are still adamant opponents. Without being able to come up with any better explanation as to why a low-carbohydrate diet works (it does) they still don’t want to accept this explanation. They come up with all kinds of objections. Some don’t even want to recognize the most basic, that carbohydrates increase insulin levels or that a low-carb diet lowers insulin levels.

Their complicated objections don’t matter much in reality. The truth is clear in study after study on humans. Insulin levels are much higher when you eat a lot of carbohydrates and lower on a low-carb diet. The figure above (from Boden et al.) is one example.

Here are some more:

Much lower insulin levels on a low-carbohydrate diet


Figure from Noakes et al.


Figure from Hernandez et al.

Longer trials

The insulin-lowering effect of low-carb diets has also been demonstrated for fasting insulin levels, in longer RCTs like these: NEJM 2003, Lipids 2009.

Lower insulin, lower insulin, much lower insulin

Does a low-carbohydrate diet lower insulin? There is only one answer: Yes, insulin levels decrease greatly throughout the entire day.

One could only wish that the insulin deniers could at least accept something this basic.


The #1 cause of obesity: insulin

It’s the insulin, stupid!

LCHF for beginners

How to lose weight


Even fasting insulin levels have been shown to be lower on a low-carb diet (for example: Samaha et al., Volek et al.)

1 2


  1. Mike
    I'm confused on why the baseline was higher than the high carb diet on the last graph.
  2. Sabine
    Great graphs!

    I just read this abstract:

    "In healthy Swedish 4-y-olds from well-educated families, low fat intake was related to high body mass index. Upward weight and height percentile crossings were related to insulin resistance, especially in girls."

  3. Renaud
    About the graph from Noakes et al. : this is not an OGTT but a meal tolerance test, so each group ate a "typical" meal for their diet.
    - VLCarbs ate 4g carbs
    - VLFat ate 89g carbs (High carb 1) or 60g (High carb 2)

    So 4g carbs don't spike insuline... nice finding ;-)

    BTW, the study is very interesting, and raises lots of questions. If ou want to read it in full :

  4. Renaud
    @Mike : that's because high carbs (low fat) "train" your body, and it becomes better at handling carbs... unless you eat more fat. The hell is realy in mixing too much carbs and fat.

    LCHF reduce insuline, but for a large part because there is a lot less glucose to handle.

  5. Suzie_B
    Now that you brought up the subject of insulin and carbs, I want to know about insulin and dairy. What is the insulin response of heavy cream, cheese, and butter in the context of an already LCHF diet? Anybody have any references for this?
    Reply: #56
  6. Renaud
    @Suzie_B: You'll certainly find some interesting things there :

    In dairy, proteins are "very" insulinogenic and fat tend to amplify the insuline response. But butter in isolation would have nearly no effect on insuline, and cream just a bit more (still low in protein). On Peter's blog, you can see the effect of cream vs. casein.

    To be fair, carbs are (generally) more insulinogenic than proteins.

    But to be fair also, insulin is a lot more than an evil fat pusher... it's a highly useful anabolic hormone. A vital one. And it's not evil.

  7. Sabine
    High carb diets are bad, especially if they severely restrict fat,
    as this will lead to multiple vitamin and mineral deficiencies,
    neurological damage, immune system malfunction,
    mental health problems,......................................and so on.....
    It is especially nasty if this is being pushed on pregnant/young women and children.

    Being low-fat does NOT make a high-carb diet any safer. (Even though this is often being stated, I doubt that this is true overall.)


    .....and so much more
    You may also be interested in this regarding dairy. (Not so evil after all!) Store-bought dairy is mostly highly processed and adulterated food, of course, and does not resemble the real thing. I eat high fat diary liberally, with great success.

    Reply: #21
  8. Sabine
    Heart surgeon openly admits low-fat diets recommended for years by mainstream medicine actually cause heart disease
    Processed sugars and grains, high omega-6 oils like soybean and corn all responsible for epidemic disease

    Learn more:

    It is very important to cut out the (unhealthy) carbs AND increase the (healthy) natural fats.

    And then there is this one:

    Fat people lack vitamin D, because they are fat (not only the other way around).

    (cannot find the other study right now, where it states that high-carb reduces Vitamin D receptors on the cells)

    Cutting the carbs will fix this, cutting fatty foods (natural fats) will make this worse.

  9. Liam Rubel
    If the insulin levels are decreasing in low carb diets than it is not a good option for the Diabetic patients as they have to keep the insulin levels balanced to avoid any sort of risks. <Lowing insulin is worst side effects in any diet plan.
    Reply: #12
  10. dr-no
    You shouldn't only mention the effects of insulin on weight. Weight is a marker of disease, not the cause. The cause is insulin. Let's name a few:
    - Years of high insulin causes arteries to constrict and grow their muscle layer (-> hypertension)
    - Insulin acts as a functional aldosterone agonist on the kidneys, thus retaining volume (-> hypertension)
    - Insulin inhibits active uric acid excretion in the kidney (-> gout)

    And the list goes on. You just have to search for it.

  11. robert
    @Liam: care to elaborate that a bit?
  12. FrankG
    Liam: a Type 1 Diabetic may be characterised as having little to no insulin being secreted by the beta cells in the pancreas (endogenous insulin). Some Insulin is necessary for human life; in which case a Type 1 will need to inject (or infuse) exogenous insulin.

    A Type 2 Diabetic may be characterised as having too much insulin -- at least in the years leading up to diagnosis... by the time of diagnosis we may have lost upwards from 50-80% of our insulin secreting capacity... which means: the few remaining beta cells are working flat out to maintain the "balance" between high Blood Glucose levels and life -- if that stress continues they will likely also burn out.

    In both cases high levels of insulin (endogenous OR exogenous) may be harmful -- as laid out by dr-no)

    Restricting dietary carbohydrates is an effective way to reduce the amount of insulin that we need to secrete or inject.

  13. FrankG

    Traditionally (and this is a generalisation) a Type 1 would limit the number of injections per day and err on the side of safety by running with a slightly higher than normal Blood Glucose (BG). Too much insulin, without Glucose to balance it, can lead to a dangerously low BG levels.

    These folks would invariably be lean, verging on skinny and many needed to lead a very structured day.

    Nowadays with the advent of continuous insulin infusion devices or "insulin pumps" a Type 1 may infuse as much insulin as they desire, to balance what they eat.

    Increasingly there are Type 1s who look more like the "normal" population: overweight, obese, metabolically disordered and in more and more cases going on to develop Type 2 or "double diabetes" as well.

    Ask any Diabetic -- "It's the Insulin Stupid!" :-P

  14. Emaho
    I like the simple graphic carbs -> insulin -> obesity. However, as a Type 1 diabetic, i don't think it explains all of the damaging effects of high insulin levels. Maybe the following would be better:

    carbs -> insulin -> obesity
    . . . . . . . . I
    . . . . . . . . I-> excess hunger -> more carbs -> more insulin -> more obesity
    . . . . . . . . I
    I-> more hunger -> etc.

    Not only is insulin a fat storage hoirmone, it also increases hunger when it is not actively dealing with glucose because of low blood sugar. It becomes a vicious obseity cycle.

  15. Emaho
    Oh well my graphic didn't display the way i thought it would. Maybe someone with better blogging skills could make an arrow come off the 'more insulin' to show that more insulin makes more hunger, etc.

    Maybe, i'll try again.
    I like the simple graphic carbs -> insulin -> obesity. However, as a Type 1 diabetic, i don't think it explains all of the damaging effects of high insulin levels. Maybe the following would be better:

    carbs -> insulin -> obesity
    . . . . . . . . I

    . . . . . . . . I-> excess hunger -> more carbs -> more insulin -> more obesity
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I -> more hunger -> etc

  16. yuma
    The Dr. stated:
    Too many (bad) carbohydrates – > pathologically high insulin levels – > obesity

    For the benefit of LCHF neophytes and potential adherents, I'd like the Dr. or somebody as knowledgeable, to describe what is "Too many carbohydrates" and what are "(bad) carbohydrates" in order to design an effective LCHF way of eating.

    I also wish that more emphasis was placed on LCHF reduction of FBG, considered by many the main indicator of potential cardiac problems.

    Reply: #18
  17. FrankG
    There is no magic formula that works the same for everybody (or even every body)

    As Doctor Andreas already stated in this blog post "What constitutes “too many” varies from person to person depending on sensitivity and activity level (how much carbs you burn). Intensely exercising young men can often tolerate a fair amount of carbs, while heavily overweight older diabetics can only tolerate minimal amounts without problems."

    For me "bad carbs" are the simple sugars and refined starches as found in processed and packaged food e.g. soda, breakfast cereal, pasta, bread, cakes etc... These do not exist in real whole food (usually does not require a label) with the exception of honey, sweet fruits and possibly starchy root vegetables.

    Some may be able to eat real whole food including fruit and starchy root vegetables, while others (like myself) cannot tolerate many, if any, of these without adversely affecting my Blood Glucose (BG).

    You may find it useful to invest in a BG meter (the test strips are what tend to cost the most) and do some self-experimenting to find out which foods you can tolerate and which you can't... basically if you don't have Diabetes and a food tends to raise your BG, you can assume it is also raising your insulin. If you eat it often, then your insulin will be raised more of the time.

    Eating real whole food, locally sourced and prepared at home is (for me) the simplest approach to an LCHF diet... not need for any fancy formulas... just as nature intended for humans and every other animal.

  18. Zepp
    Its induvidual.. but one can say that one can cut out all sugars and sweet, refined carbs and sodas!

    People can live on high carbs too, but they usaly eat them as whole food.. like tubers, vegetabels and fruit!

    Or as Gary Taubes says.. if we didnt eat those refined carbs we can probably eat the rest!

  19. FrankG
    I'm not a fan of relying on a single snapshot of my BG like the Fasting BG (FBG) usually taken first thing in the morning...

    BG is constantly changing (hopefully staying within the normal range) but to focus on just FBG is like doing the weather forecast based on a series of measurements taken only at 8am each day for a month, while ignoring what happens over the remainder of each day.

    For myself (with Type 2 D) my FBG is usually the worst of my day (but only just above normal)... eating LCHF has given me very stable and predictable BGs through the rest of the day with only my FBG raised, by what is called Dawn Phenomenon.

    FBG may serve as risk predictor of CVD but only insomuch as Type 2 Diabetes is a risk factor for CVD and a raised FBG is often one of the first symptoms detected by Doctors when someone is diagnosed with Type 2. BUT this misses the fact that the Type 2 has probably been developing for many years prior to that fateful day of diagnosis... and just as it tends to progress downwards after diagnosis (especially if one follows the standard advice) its progression could also have been slowed, stopped, or even reversed by even earlier detection.. for example by administering an OGTT which challenges the system to handle a mass influx of Glucose.

    Unfortunately the ADA and other august bodies prefer to consciously err on the side of under-diagnosis in order to spare people a potentially awkward and costly diagnosis... for example it can adversely affect your insurability.

    In my opinion this is short-sighted; as surely it is far easier to lower the water pressure and shore up a dam BEFORE it has burst through?

  20. yuma
    @ FrankG: Outstanding response.

    @ Zepp: Concise and to the point

    Both: Thanks!

  21. Wade Henderson
    "High carb diets are bad, especially if they severely restrict fat,
    as this will lead to multiple vitamin and mineral deficiencies,
    neurological damage, immune system malfunction mental health problems,......................................and so on."

    Gosh, Sabine, that explains why 82% of Dean Ornish's patients were hospitalized during his studies. I suppose Medicare will stop paying for his treatment plan when they find out what you know.
    . Ya think...?.

    Reply: #22
  22. Zepp
    I realy think she means a SAD low carb diet?

    Dr Ornish is not that dumb that he put people on a diet short of nutrients!

  23. David
    Good comments on Type II Frank. Unfortunately overnight FBG is one of the last dams to burst. By the time T2s are finally 'confirmed' they have not only been experiencing high BGs for many years but also low BGs in the form of swing excursions. These excursions can do more damage than moderately high but stable BGs. A lot of T2s find out they are diabetic only after they experience a related medical event like a stroke.
  24. Ondrej
    Chronically elevated insulin won't lead to net fat gain in the absence of a surplus of energy.
    Keep in mind that dietary protein is also insulinogenic, and that the body can store fat in the absence of insulin (via acylation stimulating protein) - two facts that these neo-Atkins types COMPLETELY ignore, either due to genuine ignorance, or to sell books.
    Reply: #25
  25. Zepp
    Then I want to know how peopel do behave when they are hypoglycemic?

    One dont fell any good with cronicaly eleveted insulin levels.. one get hungry and tired!

    One is forced to deliver surplus energy!

    ASP do only react on Chylomicrons.. how only is delivering a small part of your meals.. ie, only longer fatty acids.

    And insulin is still the major regulator of esterification and reesterification of triglycerids.

    How does one get the FFA out to make ATP in cells if Insulin inhibit the lipolysis?

  26. rita
    Does anybody know if a LCHF diet has anti-aging properties because of the low insulin levels it causes? I read about the benefits of calorie restriction and fasting before but what about LCHF? The number of calories ingested isn't low because of the fat content but the insulin levels are low. What do you guys think?
  27. Zepp
    Well aging is a natural thing.. but one want to be healty that time anyhow.

    If one is att nomal weight.. one dont get excesses of calories.. and I think its the excesses that bad.. not the normal amounts of food.

    I never seen that a to low consumption of energy and nutrients have any benefits?

    I think its a misconception.. that starving should be a better alternative to binge eating!

  28. Ondrej
    Zepp: Read Diet Recovery 2 by Matt Stone. Maybe you'll be forced to change your present views.
    Reply: #30
  29. Zepp
    Well Im not that impressed of MS.. either he is a Nobel prices candidate, or he is making things up, by him self!

    Ask any of your medical teachers what hapens if you inject insulin (satiety hormone??) without eating any carbs!

  30. Greg
    Matt Stone? The guy changes his diet every week and claims that it "cured" all the ailments he had on the previous diet. He has close to zero credibility.
  31. 1 comment removed
  32. jane
    hi doc my husband is fat but he has being found with low insulin pls advice.
    Reply: #33
  33. Zepp
    How low?


  34. Jen
    Hi would live to hear anyone's option or help advice ect......

    I have high blood levels even though I'm on a very low carb high fat diet....even moderate protein. But why is my body still rising insulin?
    My main question is even though I'm eating low carb (<10) and moderate protein (<30) will my body still store all the high fat I've been consuming? So rendering this whole lifestyle pointless :

    Jen x

    Reply: #35
  35. robert
    Less than 30g of protein per day? That sounds too little. Personally I try to stick to about 1g protein per kg of body weight +- a little wiggle room.

    If a blood test clearly shows that your fasting insulin level is abnormally high with so little protein in the diet while eating a strict low-carb, then something is quite odd. Something else must be triggering your pancreas to push out so much insulin. I've read that some people have issues with certain types of protein, maybe dairy. But still, 30g per day is not much at all.

    Be aware that a very strict low-carb diet induces insulin resistance in the muscles (they are forced to use fat and ketones and spare the little glucose that is there for the brain), but that is perfectly normal when there is no glucose coming in via the food - and it will go away after a few days, should you choose to eat more carbs. Still, while eating low-carb food insulin levels should be quite low.

    Regarding "piontless":

    It is a fact that carbs drive up insulin levels and may increase insulin resistance (the bad kind, not the one mentioned above). So if you already have trouble in that area, going back to pizza, pasta, bread and coke won't help at all.

    I don't know if you feel good on low-carb, maybe you're a bit too strict with it. If that is the case, maybe try a little relaxed version of it (paleo, primal...). Stick to real food stuff, avoid processed crap, but don't be like the "Spanish Inquisition" about every single piece you eat. Cooking and eating should still be fun.

    If you're concerned about your blood-work, talk to your GP about it. But please make sure he knows and understands the implications and effects of a low-carb diet on the body. Otherwise things might get a bit chaotic and you may end up with bad advice / medication that you don't really need.

  36. Jen
    Hi Robert,

    Thank you for the reply and really good insight!!
    I have been to the GP but my first visit was a case of "you should not be on such a low carbohydrate, recommended daily allowance ect" then I went a week later and asked the same thing to a different practitioner, her advice said I don't meet the general criteria recommended for a detailed blood work test....(basically it was nearly 5 o'clock and she wanted to go home, rushing through the whole appointment)
    So I turned to here for advice on if it was normal or if people have overcome it.
    I've been eating low carb for about 3-4months now and at first no problem. It has been in the past 3 weeks or so its started. I could try an be less strict. But defiantly staying away from processed crap!!!
    I'm just more bloated than I normally am and have gained inches too. Which is making me think about lowering fat because my body won't initially burn it off because of the high levels. This is also the reason I do not want to raise protein more too because because its already raised it will be even worse due to overflow leading to a rise too.
    If we all produce insulin regardless (just at lower levels on low carb diet) then won't we still be storing fat just on a smaller scale?

    Many thanks again for your advice and understanding
    Jen x

  37. 1 comment removed
  38. Jen
    Could stress or exercise push out excess insulin? Maybe high cortisol?
  39. Zepp
    Fat are stored whitout insulin too.. by ASP!

    Soo its not about storing.. its more about never burning it!

    One store a major part of the meal anyhow, but then one live on that storage betwen meals.

    But if one eat a lot of carbs.. one get higher insulin and that cut of fatoxidation and store more fat.. and when your blood sugar goes down you get hungry again.

    Dont be worry if insulin doing its jobb.. its when one got elevated insulin levels one got a problem.

    Try this!

  40. Dave
    Sorry to hop on the discussion,

    So only when it's elevated insulin (meaning more than normal??)it stores excess body fat?
    Also what does ASP mean?


    Reply: #41
  41. robert
    "Metabolic response of Acylation Stimulating Protein to an oral fat load"


    As far as I'm informed there is the insulin side of things: 1) remove glucose from the blood, shove it into the cells (including the liver, which may make fat if glycogen stores are full - the case for most normal people eating carbs) 2) make sure fat stays in the fat-cells by inhibiting an enzyme that breaks down fat, so it could get out again to feed the body. Store that fat for harsh times, when no food (especially carbs are available). Much like a savings account, no immediate access.

    This ASP protein was new to me, I don't know much about it, I just had a look at the paper I linked above. It seems to be able to move dietary fat into fat cells (which sounds normal as well), but I haven't checked so far if it has any role in keeping the fat in the cells locked away - which I wouldn't expect. If you eat a lot of fat, it has to go somewhere until the body actually needs it - much like a checking account, immediate access.

    Reply: #42
  42. Zepp
    You got it right.. ASP is triggerd by Chylomicrons.. that transport fat from your intestine in to your blood after a meal!

    And it supose to be stored.. becuse one cant have to much energy in the blood at the same time!

    But then.. when one need to burn the fat betwen meals for energy, its insulin that regulates the lipolysis and the formation of FFA!

    Insulin is the major regulator of esterification and reesterification of triglycerides in fat tissue!

    Lipolysis goes on the whole time.. and the regulation is mostly that it can form FFA or new triglycerids.

    When lipolysis do happens, it break down triglycerids by hydrolysis and the end product is fatty acids and glycerol.. if one got high blood sugar and high insulin levels it promote reesterification to new triglycerids by taking new glukos frome the blood and make it glycerol and bind it with fatty acids to a new triglycerid!

    And the old glycerol goes to liver and transforms to glucose!

    If one have low blood sugar and low insulin levels the fatty acids bounds to albumin and make FFA, that is the transport medium of fat fore use as energy.

    Moste is used in the muscles but if the levels of FFA is high.. more goes to the liver that convert it to keton buddies.. for replacement of of glucose!

    Becuse.. high levels of FFA and high levels of glucose are not comperative.. only if one got metabolic syndrome.. but thats a sign of a sick metabolisme!

  43. Kate
    I'm very uneducated when it comes to this area. So could you possibly dumb it down a little for me...ok ok a lot :) (I did say I was uneducated in this field)

    I've been eating lchf for a solid 5 months now, but as far as my understanding goes, if I have high insulin won't that make my body store fat and prevent me from burning it? Even though I'm eating <10 carbs and moderate protein and very high fat?

    I appreciate any response.....hopefully dumbed down to my level ;) as I know this is a old thread.

    Reply: #44
  44. Zepp
    Yes your right.. if you have high insulin you are not able to burn that much fat!

    But.. if one got high insulin and eating very litle carbs one have a medical condition.. and one would feel awfull!

    Soo if you feels normal and eats quite little carbs.. then you dont have high levels of insulin.

  45. Philip
    Kate, it depends a bit on your definition of moderate protein intake. Its considered that 0.8....1.0

    grams of protein per Kg of body weight is sufficient. Some of the protein is converted into glucose

    so that if you overdo it, your blood glucose may rise too much which will cause your pancreas to

    excrete more insulin and subsequent fat storage.

    In any event its worth checking whether or not you are eating too much protein.

  46. Lincoln
    Yes, I do believe a high-carbohydrate diet with meat is worst for your insulin levels than a low-carbohydrate diet with meat.

    But, a whole food, animal product free diet is even BETTER!

    High-carb, low-carb, it doesn't matter if you are eating whole foods and avoiding meat.

    Reply: #47
  47. robert
    Well, I hope you'll invite us all to your Nobel Prize party one day. That knowledge should be worth something.

    On the other hand... Mr. Obama got one too, and the longer I think about it, the less impressive that particular decision appears.

    Just thinking aloud...

    P.S. I'm not a hamster!

  48. Ali
    I was eating LCHF for three years but not only did I gain over 30lbs on top of my ample frame, my insulin resistance worsened to the point that the injected insulin barely does anything.

    At present I am trying fasting and low calorie eating. i'm getting desperate. I know taking more insulin isn't the answer, it never really was. My blood sugar came down to normal (with no insulin) after 4 days of water fasting, but went up as soon as I ate something. Green and low carb veg seems ok, I but I don't think I can live on that indefinitely. Maybe I can try Raw for 30 days or something. Shame it isn't Summer... :0(

    Reply: #49
  49. robert
    So you are afflicted by T2DM.

    As eating low carb veggies seems to have worked, what "something" were you eating which raised your glucose levels? I realise your case might be a special one, but usually people need much less bolus insulin when cutting carbs to 20g per day or thereabouts.

  50. Ali
    Yes, I should need less insulin, and I do, as long as I limit my food to vegetables, mainly.

    I was eating LCHF for over three years, but my resistance worsened, and I was having to take more insulin. Other people have great success, even getting off it altogether, but not me. I have tried to keep my insulin under 50 units per day because I knew taking more insulin isn't the answer, but my BG levels are often in double (mmol) figures.

    I cannot eat anything sugar-derived, not even berries, or a little dark chocolate without my levels spiking. Yesterday I started at 6.7 FBG. During the day I had 2 cups of coffee with cream, two thin slices of Gouda wrapped around some lettuce, then in the evening a base made of egg, mozzarella, ground almonds topped with salad, halloumi, bacon, mushrooms, and after, three squares of dark nut chocolate.

    I didn't take any insulin because I wanted to see what would happen. My BG went up to 12.7mmol and stayed there. I then took 14 units of the Hypurin 30/70 around 10pm, and when I went to bed 2 hours later it was still 12.7. I had another 8 units before going to sleep, and it was 7.9 this morning.

    I don't know whether I would be better off with different insulin, but for all the good it is doing I would rather be off it completely. And if I can find any way to get off it completely, I would gladly do it. I hoped LC would make me more sensitive, but it didn't. Quite the opposite. I am female. It seems it doesn't always work so well for women.

    If I water-fast for 3 days, my BG will fall to normal without any insulin. Maybe I just need to bite the bullet and do an extended fast to try and 'reboot' my body and clear out the clog.

    Reply: #51
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