Tuesday, December 22, 2009

What's the Ideal Fasting Insulin Level?

[2013 update.  I'm leaving this post up for informational purposes, but I think it's difficult to determine the "ideal" insulin level because it depends on a variety of factors including diet composition.  Also, insulin assays are not always comparable to one another, particularly the older assays, so it's difficult to compare between studies]

Insulin is an important hormone. Its canonical function is to signal cells to absorb glucose from the bloodstream, but it has many other effects. Chronically elevated insulin is a marker of metabolic dysfunction, and typically accompanies high fat mass, poor glucose tolerance (prediabetes) and blood lipid abnormalities. Measuring insulin first thing in the morning, before eating a meal, reflects fasting insulin. High fasting insulin is a marker of metabolic problems and may contribute to some of them as well.

Elevated fasting insulin is a hallmark of the metabolic syndrome, the quintessential modern metabolic disorder that affects 24% of Americans (NHANES III). The average insulin level in the U.S., according to the NHANES III survey, is 8.8 uIU/mL for men and 8.4 for women (2). Given the degree of metabolic dysfunction in this country, I think it's safe to say that the ideal level of fasting insulin is probably below 8.4 uIU/mL.

Let's dig deeper. What we really need is a healthy, non-industrial "negative control" group. Fortunately, Dr. Staffan Lindeberg and his team made detailed measurements of fasting insulin while they were visiting the isolated Melanesian island of Kitava (3). He compared his measurements to age-matched Swedish volunteers. In male and female Swedes, the average fasting insulin ranges from 4-11 uIU/mL, and increases with age. From age 60-74, the average insulin level is 7.3 uIU/mL.

In contrast, the range on Kitava is 3-6 uIU/mL, which does not increase with age. In the 60-74 age group, in both men and women, the average fasting insulin on Kitava is 3.5 uIU/mL. That's less than half the average level in Sweden and the U.S. Keep in mind that the Kitavans are lean and have an undetectable rate of heart attack and stroke.

Another example from the literature are the Shuar hunter-gatherers of the Amazon rainforest. Women in this group have an average fasting insulin concentration of 5.1 uIU/mL (4; no data was given for men).

I found a couple of studies from the early 1970s as well, indicating that African pygmies and San bushmen have rather high fasting insulin. Glucose tolerance was excellent in the pygmies and poor in the bushmen (5, 6, free full text). This may reflect differences in carbohydrate intake. San bushmen consume very little carbohydrate during certain seasons, and thus would likely have glucose intolerance during that period. There are three facts that make me doubt the insulin measurements in these older studies:
  1. It's hard to be sure that they didn't eat anything prior to the blood draw.
  2. From what I understand, insulin assays were variable and not standardized back then.
  3. In the San study, their fasting insulin was 1/3 lower than the Caucasian control group (10 vs. 15 uIU/mL). I doubt these active Caucasian researchers really had an average fasting insulin level of 15 uIU/mL. Both sets of measurements are probably too high.
Now you know the conflicting evidence, so you're free to be skeptical if you'd like.

We also have data from a controlled trial in healthy urban people eating a "paleolithic"-type diet. On a paleolithic diet designed to maintain body weight (calorie intake had to be increased substantially to prevent fat loss during the diet), fasting insulin dropped from an average of 7.2 to 2.9 uIU/mL in just 10 days. This is despite a substantial intake of carbohydrate, including fruit and vegetable sugars.  The variation in insulin level between individuals decreased 9-fold, and by the end, all participants were close to the average value of 2.9 uIU/mL. This shows that high fasting insulin is correctable in people who haven't yet been permanently damaged by the industrial diet and lifestyle. The study included men and women of European, African and Asian descent (7).

One final data point. My own fasting insulin, earlier this year, was 2.3 uIU/mL. I believe it reflects a good diet, regular exercise, sufficient sleep, and a relatively healthy diet growing up. It does not reflect: carbohydrate restriction, fat restriction, or saturated fat restriction.

So what's the ideal fasting insulin level? My current feeling is that we can consider anything between 2 and 6 uIU/mL within our evolutionary template.

51 comments:

Anonymous said...

Very interesting. I find it particularly interesting that the participants in the study footnoted as #7 had such a drop in insulin, even though the diet couldn't possibly have been particularly low in carbohydrate... unless it's inaccurate that they ate mostly "lean meat, fruits, vegetables and nuts". Do grains, dairy and/or legumes have some kind of insulin-stimulating properties independent from their carb content?

David said...

Stephan, What do you think about meal frequency as a factor in fasting insulin and disease in general? What's your frequency like? Dr. Ornish promotes grazing whereas Dr. Davis has been advocating against it...

David said...

Also, the link to the paleolithic diet you posted didn't work, but according to the similar study linked below, there was a huge reduction in fasting insulin levels, but their paleo diet had massive amounts of fructose... any thoughts on that? Also, it had high meal frequence - 6 a day...

http://www.healthinsight.co.za/Dietary%20Fats,%20Fatty%20Acids%20and%20IR%20-%20Haag,%20Dippenaar.pdf

Mario Iwakura said...

Stephan,

Very interesting post!

Along these lines, a post that I would like to see from you is: "What is the expected total cholesterol level on a healthy person?". Is a low total cholesterol normal in a healthy person (not taking statings, of course!) or it's a symptom of disease, since there is dozens of studies linking low cholesterol to infecto diseases, cancer, celiac, depression and alzheimer.

Jenny said...

Unfortunately, there is a missing element here. The genes found in most people have relatives with Type 2 diabetes turn out to cause lower than normal insulin production. When young and slim, their insulin is already too low to control blood sugar to optimal rates.

A low insulin level, therefore, is ONLY a sign of health if it is found in conjunction with a low normal fasting blood glucose--70 mg/dl-83 mg/dl.

If the insulin is low and the fasting glucose higher than 83, you may be looking at a very early indicator of a problem with beta cells, NOT an indicator of health.

The Pacific Islanders have the highest rate of Diabetes in the world with a unique genetic defect causing their diabetes not found in European populations. Their low insulin might be a sign of the presence of a mildly defective gene causing low insulin production, NOT of health.

Monica said...

Would be great to have some data on cultures with high amounts of dairy in their diet but with diets that are otherwise clean, e.g. the Masai. I've been intrigued about Cordain's assertion that dairy raises insulin as much as white bread. I haven't checked into those references.

Don Matesz said...

Following up on paleoish, I see that in table 1 of Frasseto et al they report that the "paleo" diet averaged about 329 calories more than the usual, and had an average carbohydrate content of 249 g per day compared to 254 for the usual diet (both having a similar range of variation). Yet paleo diet group had a drop of 68% in fasting insulin.

Especially interesting since the paleo diet contained honey at breakfast and 4 servings daily of carrot juice (unprotected carbohydrates). This certainly does suggest that the paleo carbs had less insulinogenic effect than the usual diet's carbs.

Don Matesz said...

Jenny,

"Their low insulin might be a sign of the presence of a mildly defective gene causing low insulin production, NOT of health."

Defective? Depends on what they eat. Not defective on their native diet if they don't have diabetes. The food that brings out the so-called "defect" is what I would call defective.

Dr. B G said...

Art DeVany's fasting insulin is as negligible as yours Stephan (I don't have access but I recall it was like 2 or 3).

Good post!! :)

Don, I concur w/comments!

Stephan Guyenet said...

Hi Paleoish,

Yes, the Kitavans eat a high-carb diet too. Carbohydrate itself doesn't raise fasting insulin, as far as I can tell. I think there's something about the modern diet/lifestyle that causes insulin resistance and high fasting insulin, but it's not as simple as "too much carb" or "too much fat".

Hi David,

Fixed the link, thanks. I'm not in favor of grazing. By doing that, you're keeping your body in "deposit" mode all day, with not much time for "withdrawal". I eat three solid meals on most days with virtually no snacks.

The paleo diet included three meals and three snacks per day, and was probably relatively high in fructose as you said. I don't know if you could call the amount "massive", given that they didn't quantify it in the paper.

Hi Jenny,

Good point, if someone is losing islet function, their insulin will be low as well.

Hi Monica,

Yes, dairy raises insulin after a meal, but there's a difference between post-meal insulin spikes and fasting insulin level. Just because a food spikes your insulin after you eat doesn't mean it will cause insulin resistance and high fasting insulin.

Hi Don,

Yes, it's not exactly how I would design a paleo-type diet, but it did seem to be effective. My guess is that it succeeded despite the frequent meals and relatively high fructose content, rather than because of them. The fiber content of the diet must have gone way up, although it wasn't reported.

Don Matesz said...

I wonder if changing the sodium:potassium ratio or raising pH plays an important role in regulating insulin production or disposal.

The usual diet had a nearly 2:1 Na:K ratio, the paleo had nearly 1:4 Na:K, similar to the ratio in fresh meat or human milk.

Urinary pH increased by 0.34 in the paleo group.

Magnesium intake nearly doubled.

David said...

Thanks Stephan - a related question: do you mix carbs, fat and protein at each meal? or do you avoid mixing fat and carbs? do you think it matters?

Stephan Guyenet said...

Hi Don,

My guess is that removing some of the worst neolithic offenders was the main reason for the benefit. I'm starting to think that gut health is central to everything. But the things you mentioned did cross my mind. Mineral sufficiency/balance is important.

Hey, what's your take on vegetables? The thing that I find strange about it is that according to Cordain's paper based on Murdoch's ethnographic atlas, most HGs didn't eat many low-calorie vegetables. Maybe the atlas is just inaccurate, having overlooked vegetables in favor of more calorie-dense staples. I know some HG cultures ate vegetables, and others clearly didn't. I'm now coming around to the idea that they're good to have in the diet rather than simply incidental. Any thoughts?

Lee said...

"I'm starting to think that gut health is central to everything"

Have you come across the the Specific Carbohydrate Diet? It aims to remove all complex carbs, including disaccharides, from the diet, saying that for many people, these are hard to digest and cause gut ill-health. It allows non-starchy vegetables, fruit and honey.

I am sure that you will point out that there is a great difference between one starchy food and another, wheat vs potato, for instance. But it made me realize the importance of poor lactose digestion in many people, even in northern Europeans such as me. If sucrose digestion is also problematic, then this could be an overlooked issue of modern diets.

Don Matesz said...

Hi Stephan,

In the AJCN paper, Cordain cites Brand Miller's report (Australian Aboriginal plant foods: a consideration of
their nutritional composition and health implications, Nutrition Research Reviews (1998), 11, 5-23) of proportions of plant foods in Aborigine diets (As percent of total plant food consumed):

Fruits 41%, seeds and nuts 26%, USOs 24%, and leaves, dried fruits, gums, and miscellaneous parts all together 9%.

If we assume a 40:60 plant:animal subsitence ratio (about average for H-Gs by Cordain's AJCN estimations), then we could estimate that proportions of energy from each of these four classes would be:

Fruits 16%, seeds and nuts 10%, USOs 10%, and leaves etc. 4.0%.

These would result in LARGE intakes of fruits and vegetables due to the relatively low caloric density of these foods.

For example, 4.0% of calories as leaves, for a 2000 calorie diet, would be 80 calories. That would be 7-8 cups of raw collards, which would cook down to 1-2 cups.

10.0% of calories as USOs would tranlate to 200 calories, roughly two medium sweet potatoes or 4 cups of carrots (raw, chopped).

So, I believe H-Gs eating mixed diets ate pretty large amounts of vegetation. After reading Wild Health by Cindy Engel, I feel pretty sure that H-Gs knew to eat vegetables for nutritional and medicinal properties independent of energy content.

Don Matesz said...

Stephan,

I definitely think we need vegetables for optimum health and longevity. Yes, we can live on meat alone, or meat and tubers, etc., but surviving and thriving over a long haul are two different goals.

Stephan Guyenet said...

Hi Don,

I believe those represent the number of items gathered, not their caloric density. If 3.6% of the items they gathered were leaves, that doesn't represent much of a contribution to the diet. It looks to me that they favored tubers and nuts, and ate a few vegetables here and there.

Don Matesz said...

Hey Stephan,

Following my hunch that I had read something about the Na:K ratio affecting insulin action, I checked in my copy of The Salt Solution, co-authored by Mark McCarty, Herb Boynton, and Richard Moore, M.D., Ph.D., a biophysicist who has done basic work in this area.

To quote (p.153): ...there is considerable evidence that, over time, slowing the Na/K pump indirectly increases the tendency to develop 'insulin resistance.'" In short, depletion of body K results in high intracellular levels of Ca2+, which decreases the cells' ability to remove glucose from the blood.

Thiazide diuretics, prescribed for hypertension, deplete K and have insulin resistance as a side effect.

Don Matesz said...

Stephan,

If they were counting number of items, there are too many problems with that as data. First, do you count each leaf as one item, or if you collect a lettuce-like plant with many leaves, is that one item or is each leaf an item?

Brand-Miller states that Aborigines used 317 species of fruits, 28 species of leaves, 14 species of misc vegetables, 16 flower and 2 gums. So, 60 total species of leaves, flowers, etc.

If 317 is 41% of total plant species used, the total would be 773 species used. Then 60 misc species (including leaves) would be 8% of species (close to the 9% I quoted).

Re leaves, of course use would vary with tribal location, but I feel inclined to think H-Gs would have used edible leaves when ecologically possible. Leaves play a large role in other primate diets, and an important role in traditional agricultural diets and herbal medicines. I find it hard to believe that the agricultural use of leaves as food did not have a well-established H-G (paleo) precedent, given the extensive use of leaves by other primates.

David said...

Japanese consume massive amounts of salt and relatively low amounts of vegetables and have low fasting insulin levels.

Anonymous said...

Monica, Stephan,

Regarding the statement that dairy results in increased insulin, it seems to me that milk would increase insulin due to the carbohydrates content, but that dairy products that contain virtually no carbohydrates, such as cream, butter and aged cheese, would not stimulate an increase in insulin. Am I wrong on that?

ItsTheWooo said...

I am glad we are finally starting to agree that "too much fat" and "too much carb" does not cause metabolic dysfunction... however, fat/carb certainly must be controlled once that dysfunction already exists.

Speaking personally, I have discovered that micronutrients make a big fat huge deal in determining metabolic health.
I have also discovered that many factors we would not necessary relate to metabolic health - like sunlight - also are extremely important.

1) Since supplementing with inositol at 3 grams per day, my capacity to tolerate carbohydrate has improved significantly.

2) Supplementing with chromium GTF has helped incredibly as well (picolinate helps less so than the GTF, in my experience).

3) Since using a light box to mimic bright sunlight, I have again noticed a dramatic improvement in metabolic function in the sense that I am far less hungry and more energetic.


It is my belief that the "modern lifestyle" slowly erodes our health resulting in metabolic disease. It dose not do this by any one causative factor, but by many, many niggling little ones that add up to big impairment.

For example, eating a very high carbohydrate diet of refined foods will cause a slow but steady depletion of chromium and inositol, leading to complications of insulin resistance and impaired insulin function.
Science has only begun to figure out the various nutrient factors relevant to good metabolic health. We know of inositol and chromium, but what others exist?

Or another example... our modern lifestyle causes people to be chronically starved of sunlight. We stay up late, wake up late, spend most of our time in offices or buildings. We are lucky to see the sun for 30 minutes to and from work.


Lack of sleep is another issue. Many of us have jobs that do not allow us to sleep 8 hrs a night. Combined with chronic light deprivation, chronic lack of sleep will also make you a metabolically diseased fatso.


Toxic levels of stress over insignificant things are a symptom and a cause of metabolic dysfunction. Metabolic disease will cause anxiety/mood disorders, but these mental health problems will, in turn, exacerbate metabolic diseases.



Healthy people do not live this way.... zero sunlight, low sleep, eating highly refined foods that are extremely dense in carbohydrate...

People are fat because of a complex interplay of all these factors, combined with genetic predisposition.

It isn't carbs or fat, it's the whole lifestyle that f*cks up one's metabolism. You can't properly process a serving of potatoes if you haven't seen the sun in days, if you have been sleeping 6 hrs a night, if you're depleted of inositol and chromium, etc.

I am also a believer in the idea that chemicals may be causing metabolic damage, which exacerbates any toxic environment.

ItsTheWooo said...
This comment has been removed by the author.
randyfeingersh said...

Jack Cameron Wrote:
Regarding the statement that dairy results in increased insulin, it seems to me that milk would increase insulin due to the carbohydrates content, but that dairy products that contain virtually no carbohydrates, such as cream, butter and aged cheese, would not stimulate an increase in insulin. Am I wrong on that?

Reply:
Its the Whey content of dairy products that causes the insulin spike.
Many protein foods (beef) will cause a higher insulin spike some high carb foods.

Refs:
http://www.ajcn.org/cgi/content/abstract/82/1/69

http://www.mendosa.com/insulin_index.htm

Regards
Randy

Jeffrey of Troy said...

Hi Stephan,

Just discovered yer blog about 2-3 weeks ago (from a comment on Eades' blog). Been reading back through old posts; excellent, thank you. Especially the stuff about pastured butter and eggs; I will have to make that change.

Stephan:
"... vegetables? ... I know some HG cultures ate vegetables, and others clearly didn't. I'm now coming around to the idea that they're good to have in the diet rather than simply incidental."

I know we have eyes in the front of our heads, supporting that we are predators not prey; and our digestive systems, though longer than pure carnivores, are shorter than vegetarian (prey) animals. But just look at our teeth. If a man walked up to you and smiled, and he had all sharp teeth like a dog or a cat, wouldn't you freak out? For us to have so many flat teeth, it was probably normal to have a substantial amount of plant food for ... well, ever, really.

ItsTheWoo:

"Speaking personally, I have discovered that micronutrients make a big fat huge deal in determining metabolic health... Lack of sleep is another issue. Many of us have jobs that do not allow us to sleep 8 hrs a night. Combined with chronic light deprivation, chronic lack of sleep will also make you a metabolically diseased fatso."

Yeah, we can't only look at macronutrients. In thinking about the Kitavans, Inuit, Japanese, etc., I thought of 5 things they had in common:
1.) Vitamin D (4000IU/d? - from sunlight and seafood)
2.) Iodine (1-10 mg/d? - from fish and seaweed) (Heart Scan Blog tipped me to the iodine thing.)
3.) A diet of whole unprocessed food, whatever the macro ratio
4.) Healthy fat (sat from animal or coconut, Omega 3 from fish)
5.) Like Woo said, SLEEP (even Americans of just 100 yrs ago averaged 9 hours /night)

Stephan Guyenet said...

Hi Jeffrey,

Welcome to the blog.

Carnivores have canines because they use their mouths to hunt. We use tools so we don't need canines. I don't think you can make much of an argument about our diet based on our tooth structure because we procure and eat food so differently than other species. However, I agree with you about the eyes and the digestive tract.

Innovator said...

it seems testing for fasting insulin could be quite useful for those of us learning from this blog!

Any practical ideas on how one can go about testing for fasting insulin?

I am researching: Is there an at home kit, or a website? Can it be done at a lab? Does it seem to be regulated by (any) state law, and thus require a prescription?

If I can make progress with my research, I will report back!

Innovator said...

My own initial research shows the test is available (at least in many states) at
Life Extension at a cost of $56 for non-members, $42 for members. This is the lowest cost I have seen so far. [I have no affiliation with Life Extension.]

Jeff Consiglio said...

Some good observations in the comments here. Several of you brough up the issue of nutrient-density or specific nutrients perhaps allowing one to "tolerate" a high carb intake.

It seems that high carb works well within certain cultures, but not so well in others.

I believe the following all contribute to "carb-intolerance" in industrialized countries.

Magnesium deficiency
Potassium deficiency
Misc. other nutrient deficiencies
Trans-fats
Refined vegetable oils
Excess light exposure at night
Chronic lack of quality sleep
Caffeine abuse
Lack of exercise
High fructose intake

And probably several others.

I know wheat and other glutens are also considered a dietary bad-guy by paleo folks, but I'm still not quite convinced of that theory yet. At least not in terms of causing chronic insulin resistance.

I have long had a bad case of "cognitive-dissonance" about LC diets, since certain cultures seem to thrive on high carb diets.

But I currently feel a high carb diet is ONLY justified in certain, very limited contexts.

For the typical sedentary, nutrient deprived American, who likely already has slight insulin insensitivity, I think some form of carb restriction id dang near mandatory.

donny said...

Just off the top of my head here, I've seen studies where resveratrol, a combination of b vitamins, taurine, glycine or glutamine all lessened or prevented the negative effects of fructose or sucrose on mice or rats. I don't think we can rule out the possibility that fructose, if accompanied by proper nutrition (or as found naturally in foods, never purified in the first place), might not only be harmless, but even beneficial in that it doesn't cause or need the secretion of insulin to be metabolized.

Stephan Guyenet said...

Hi Donny,

I'm skeptical of those types of studies (especially when they're looking at polyphenols, which are often bitter) unless they measure calorie intake. Some of those ingredients may have tasted bad to rats and mice, and they may have been eating less food consequently.

donny said...

There's another problem there though, with the possibility that these additives would cause under-consumption by making the food taste bad. If fructose disregulates leptin, and sensitivity to leptin, what effect does this have on the sense of taste? Leptin decreases carbohydrate appetite, and the preference for sweet flavours. An added substance might decrease palatability directly-- or it might do so indirectly, by somehow affecting the action or secretion of insulin or leptin. Rather than suppressing appetite, the substance might just be normalizing appetite. I guess this just adds another layer of skepticism.

Anonymous said...

Stephan,

You said on December 31: "Carbohydrate itself doesn't raise fasting insulin, as far as I can tell. I think there is something about the modern diet/lifestyle that causes high fasting insulin and insulin resistance."

I disagree with the notion that carbohydrates do not raise fasting insulin, but agree that it is the modern diet and lifestyle that are the primary cause of high fasting insulin and insulin resistance.

It is primarily glucose that stimulates insulin secretion, and increased serum insulin in turn stimulates production of the vasorelaxant nitric oxide (NO) by endothelial nitric oxide synthase (eNOS) which relaxes blood vessels resulting in increased blood flow which significantly increases the delivery of glucose to target cells.

There are many dietary and lifestyle factors which can cause endothelial dysfunction which impairs NO synthesis which reduces glucose metabolism which increases serum glucose which results in increased insulin secretion.

At the top of the list of dietary factors that impair NO synthesis is excess intake of linoleic acid. See pubmed ID 17696958) which states "linoleic acid might involve the dysfunction of both eNOS basal activity and its phosphorylation status and may then contribute to impaired vasodilation in vivo." Linoleic acid is the most atherogenic of all fats and results in oxidation of LDL which results in generation of free radicals that also cause endothelial dysfunction.

Other dietary factors:

The saturated fats myristic acid and to a lesser extent,palmitic acid, stimulate NO synthesis. Omega 3 fats DHA and EPA also stimulate NO synthsis. Deficiency of these fats therefore results in reduced NO synthesis, reduced glucose metabolism and hence increased insulin levels.

Increased Crp due to excessive intake of refined carbohydrates results in enhanced LOX-1 sythesis which results in endothelial dysfunction. The best indicator of Crp levels is waist circumference, so accumulation of belly fat results in endothelial dysfunction.

A sedentary lifestyle results in impaired NO production due to low levels of BH4.

The bottom line is that impaired glucose metabolism results in increased glucose levels that cause and increase in insulin synthesis.

MontyApollo said...

In regards to the forward-set eyes and carnivores - I read something a while back that claimed that in humans, apes, and monkees that it was an arboreal adaptation rather than a predatorial one. Better depth perception makes it easier to move through a forest of trees. Is the predator view still the most accepted?

Stephan Guyenet said...

Monty,

Very good point. Some herbivorous and frugivorous primates have forward-pointing eyes. There goes that theory.

Murray said...

Jack Cameron,

Thank you for the useful post. Based on what data and research you've seen, what is your view on nuts (such as almonds, walnuts and pecans), which contain a fair amount of linoleic acid. I can see the poison in large doses (especially relative to consumption of DHA/EPA) or in the format (extruded into cooking oils that are highly peroxidized). However, in a raw nut the fat is encased in fibre and antioxidants, which would limit oxidization. Thus, unless linoleic acid is a poison at any dose, one might be able to eat modest amounts of raw nuts (balanced by DHA/EPA from other sources) without negative effect.

Murray

lynn said...

Hi Stephen

Do you know if insulin is measured in different units around the world? I got my fasting insulin levels tested in Belgium recently and the range was: 3-22. I have been eating a low sugar, low carb diet for seven years so was bitterly disappointed and upset to find my efforts have been worthless as my fasting level was 17.9.

Is their anything ELSE besides diet that will lower insulin? Would cutting out the small amount of sugar in the Lindt 85% I eat make a difference for example? Should I stop eating in restaurants so as to avoid PUFAS? Would more exercise help?

VlC made my blood sugars higher so I am sure they were making my insulin higher also.

I am pretty depressed about the whole thing to be honest.

PRIVATE said...

I'm a little confused and need some advice. My fasting insulin a few years ago was sky high, glucose levels were normal but the 2 hour OGTT showed I was pre-diabetic. Now, a few years later, I noticed that I was losing weight fairly quickly, blurry vision, hunger, thirst and so obviously I became quite concerned and did the OGTT and Insulin as well. My fasting glucose is low, 3.3 mmol/L and fasting insulin is 14 pmol/L. After the 2 hours, my insulin 516 pmol/L and glucose 7 mmol/L. My question is, could the fact that I was eating very low carb (mainly because I seem to have a severe carb intolerance), have altered the results of my test ??

PhilipJTerry said...

Hi Stephan,

One other thing the Blue Zones have in common, and this is a big one which I believe holds most of the weight over the nutritional side, and that is Glycogen stores. They all seem to be 'working the land' which leads me to wondering if this holds most of the weight. If Glycogen levels are being depleted through continual exercise ie. working the land, their insulin will be low and also HDL levels elevated. So when they eat instead of being in deposit mode, they are in absorbtion mode whenever they eat, even if it's carbs. I the macro profile depends on the context. Carbs are only OK IF glycogen stores are depleted but if not you are just putting a force multiplier on traffic jam into the cell causing damage. As for protein a gerentologist said that for max life span excess is not good, however if the muscles need it I think it's OK but after a workout. So it's very context dependant, don't you think?

MikeBiker said...

I have been eating low carb for over 10 years now - following many years of low fat eating. I am 66-years old and in a blood test, I had a fasting insulin level of 4.0. Before I switched to to the low carb eating style. I was on the borderline of being diabetic with a high fasting insulin level. Health problems can definitely be fixed with a diet change.

Unknown said...

Thanks for the info. I have a son with a .8 insulin and 70 fasting glucose. Trying to find out the problem. The insulin is so low.

Unknown said...

I would like to make a question regarding insulin levels,but a bit more specific.
What does exacly ''insulin level'' means in terms of insulin units(i.e. in a diabetic type 1 who injects their insulin).What is the healthy insulin level( how many units of insulin should he or she inject)for a diabetic type 1(provided good glycemic control). Thank you.

Anonymous said...

Wow! My insulin was at 22 uIU/mL and I'm only 19.

Unknown said...

Hi, I'm 31 my fasting insulin is 20 and the insulin level after glucose intake is 80. Is it a matter of concern?

Terry Secord said...

I'm a 48 yr old male. 245 pounds and 5'6 (with an athletic body underneath all that fat - I used to work out a lot and be quite muscular in my teens and twenties). I'm 100 pounds over weight. I just did some blood work mainly for testosterone (which was low 161) and found the following results. I know I need to get my insulin levels way down to allow my fat to be released (like under 6, right?). I'm also concerned about my estradiol. Any suggestions would be greatly appreciated:

Dehydroepiandrosterone Sulfate: 147.1 mcg/dl (range = 48 - 244)
Estadiol: HIGH - 62.9 pg/ml (range = <29.8)
FSH: <0.3 miU/ml (range = NaN miU/mL
LH: LOW - .011 mIU/ML (range = 1.5 - 9.3 mIU/mL
Progesterone: 0.7 ng/mL (range = NaN ng/ml
Prolactin: HIGH - 19.5 ng/mL (range = 2.1 - 17.7 ng / mL
Sex Hormone Binding Globulin: 14 nmol/L (range = 10-57 nmol/L
Testosterone: 594 ng/dl (range = 72-853)
Test free: 19.54 ng/dl (range = 5-21)
Insulin (fasting) HIGH: 27.6 uIU/mL (range = 3 - 25)

If I were to be 100% disciplined about making sure at all times during the day I'm eating correctly and taking any supplementation, what should I be doing to get my insulin levels as ideal as possible? Any help is greatly appreciated.

Nancy said...

For 6 mo. I kept an aic of 5.7 and lost 20 lbs on a low carb diet. Then I had my fi checked and it was a 3 and aic was still 5.7
3 mo. Later my aic was 5.4 then last week my aic was 5.8 and fi was a 2 with fg 81. My functional med/internal med dr says that's ok but the fi of 2 scares me a little. What are your thoughts?

Rodney1111 said...

Just for the record, it may be of interest that people on seriously calorie restricted diets (see CRSociety website for details) have fasting insulin levels of around 2.0 (in US units.) I restrict calories, but not as much as most in the group, and the last time I was tested my fasting insulin was quoted as "below 14" (in canadian units. The conversion factor is 'divide by 6.945 to get US units') so in US units I was below 2, which was the low end measurement threshold for that assay method. The lab was surprised by the result so they repeated the test to confirm they hadn't made a mistake.

The calorie restriction group members are unbelievably healthy based on every measurement ever taken (take a look at Luigi Fontana's paper in 2003 and others) so, based on this, I think an ideal fasting insulin would have to be below 3 in US units.

Rodney1111 said...

To Nancy: I had not seen your post about fi of 2 when I posted mine. Your 2 is an excellent number. IMO something to rejoice about, not be scared of. My A1c is also 5.5 to 5.7 a bit like yours, incidentally. And, fwiw, I have been on a 'high complex carb' diet since 1974 - lots of whole grains. Works for me. May or may not work for others.

Rachel said...

Wow thank you for telling me what my doctor was totally unable to answer I need to talk to my doctor about this because my insulin is only one and my glucose is 89. They are going to want to see some studies. Do you have any references?

Unknown said...

mine fasting insulin is 1.26 uIU/ml ..Is it normal? my age is 23 ..

Cassie said...

Thanks for the post! I came across this as I was googling the standard range of serum insulin levels in lean vs. obese patients for my research. It looks like this is a complicated question. I appreciated these references