Thyroid, blood sugar & metabolic syndrome

July 23, 2010 in Diabesity, Thyroid Disorders | 52 comments

ultimaAccording to the American Association of Clinical Endocrinologists, 27 million Americans suffer from thyroid dysfunction – half of whom go undiagnosed. Subclinical hypothyroidism, a condition in which TSH is elevated but free T4 is normal, may affect an additional 24 million Americans. Taken together, more than 50 million Americans are affected by some form of thyroid disorder.

Metabolic syndrome (MetS), also affects 50 million Americans, and insulin resistance, one of the components of metabolic syndrome, affects up to 105 million Americans. That’s 35% of the population. Metabolic syndrome has become so common that it’s predicted to eventually bankrupt our healthcare system. Both metabolic syndrome and insulin resistance are risk factors for heart disease and diabetes, two of the leading causes of death in the developed world.

With such a high prevalence of both thyroid dysfunction and metabolic syndrome, you might suspect there’s a connection between the two. And you’d be right.

Studies show an increased frequency of thyroid disorders in diabetics, and a higher prevalence of obesity and metabolic syndrome in people with thyroid disorders.

That’s because healthy thyroid function depends on keeping your blood sugar in a normal range, and keeping your blood sugar in a normal range depends on healthy thyroid function.

How high blood sugar affects the thyroid

Metabolic syndrome is defined as a group of metabolic risk factors appearing together, including:

  • abdominal obesity;
  • high cholesterol and triglycerides;
  • high blood pressure;
  • insulin resistance;
  • tendency to form blood clots; and,
  • inflammation.

Metabolic syndrome is caused by chronic hyperglycemia (high blood sugar). Chronic hyperglycemia is caused by eating too many carbohydrates. Therefore, metabolic syndrome could more simply be called “excess carbohydrate disease”. In fact, some researchers have gone as far as defining metabolic syndrome as “those physiologic markers that respond to reduction in dietary carbohydrate.”

When you eat too many carbs, the pancreas secretes insulin to move excess glucose from the blood into the cells where glucose is used to produce energy. But over time, the cells lose the ability to respond to insulin. It’s as if insulin is knocking on the door, but the cells can’t hear it. The pancreas responds by pumping out even more insulin (knocking louder) in an effort to get glucose into the cells, and this eventually causes insulin resistance.

Studies have shown that the repeated insulin surges common in insulin resistance increase the destruction of the thyroid gland in people with autoimmune thyroid disease. As the thyroid gland is destroyed, thyroid hormone production falls.

How low blood sugar affects the thyroid

But just as high blood sugar can weaken thyroid function, chronically low blood sugar can also cause problems.

Your body is genetically programmed to recognize low blood sugar as a threat to survival. Severe or prolonged hypoglycemia can cause seizures, coma, and death. When your blood sugar levels drop below normal, your adrenal glands respond by secreting a hormone called cortisol. Cortisol then tells the liver to produce more glucose, bringing blood sugar levels back to normal.

The problem is that cortisol (along with epinephrine) is also a sympathetic nervous system hormone involved in the “flight or fight” response. This response includes an increase in heart rate and lung action and an increase in blood flow to skeletal muscles to help us defend against or flee from danger. Cortisol’s role is to increase the amount of glucose available to the brain, enhance tissue repair, and curb functions – like digestion, growth and reproduction – that are nonessential or even detrimental in a fight or flight situation.

Unfortunately for hypoglycemics, repeated cortisol release caused by episodes of low blood sugar suppresses pituitary function. And as I showed in a previous article, without proper pituitary function, your thyroid can’t function properly.

Together, hyperglycemia and hypoglycemia are referred to as dysglycemia. Dysglycemia weakens and inflames the gut, lungs and brain, imbalances hormone levels, exhausts the adrenal glands, disrupts detoxification pathways, and impairs overall metabolism. Each of these effects significantly weakens thyroid function. As long as you have dysglycemia, whatever you do to fix your thyroid isn’t going to work.

How low thyroid function affects blood sugar

We’ve seen now how both high and low blood sugar cause thyroid dysfunction. On the other hand, low thyroid function can cause dysglycemia and metabolic syndrome through a variety of mechanisms:

  • it slows the rate of glucose uptake by cells;
  • it decreases rate of glucose absorption in the gut;
  • it slows response of insulin to elevated blood sugar; and,
  • it slows the clearance of insulin from the blood.

These mechanisms present clinically as hypoglycemia. When you’re hypothyroid, your cells aren’t very sensitive to glucose. So although you may have normal levels of glucose in your blood, you’ll have the symptoms of hypoglycemia (fatigue, headache, hunger, irritability, etc.). And since your cells aren’t getting the glucose they need, your adrenals will release cortisol to increase the amount of glucose available to them. This causes a chronic stress response, as I described above, that suppresses thyroid function.

How to keep your blood sugar in a healthy range

It’s important to understand that whether you have high or low blood sugar, you probably have some degree of insulin resistance. I described how high blood sugar causes insulin resistance above. But insulin resistance can also cause low blood sugar. This condition, called reactive hypoglycemia, occurs when the body secretes excess insulin in response to a high carbohydrate meal – causing blood sugar levels to drop below normal.

In either case, the solution is to make sure your blood sugar stays within a healthy range. There are two targets to consider. The first is fasting blood glucose, which is a measure of your blood sugar first thing in the morning before eating or drinking anything. I define the normal range for fasting blood glucose as 75 – 95 mg/dL. Although 100 is often considered the cutoff for normal, studies have shown that fasting blood sugar levels in the mid-90s were predictive of future diabetes a decade later. And although 80 mg/dL is often defined as the cutoff on the low end, plenty of healthy people have fasting blood sugar in the mid-to-high 70s (especially if they follow a low-carb diet).

The second, and much more important, target is post-prandial blood glucose. This is a measure of your blood sugar 1-2 hours after a meal. Several studies have shown that post-prandial blood glucose is the most accurate predictor of future diabetic complications and is the first marker (before fasting blood glucose and Hb1Ac) to indicate dysglycemia.

Normal post-prandial blood sugar one to two hours after a meal is 120 mg/dL. Most normal people are under 100 mg/dL two hours after a meal.

Now that we know the targets, let’s look at how to meet them. If you’re hypoglycemic, your challenge is to keep your blood sugar above 75 throughout the day. The best way to do this is to eat a low-to-moderate carbohydrate diet (to prevent the blood sugar fluctuations I described above), and to eat frequent, small meals every 2-3 hours (to ensure a continuous supply of energy to the body.

If you’re hyperglycemic, your challenge is to keep your blood sugar below 120 two hours after a meal. The only way you’re going to be able to do this is to restrict carbohydrates. But how low-carb do you need to go? The answer is different for everyone. You figure your own carbohydrate tolerance by buying a blood glucose meter and testing your blood sugar after various meals. If you’ve eaten too many carbs, your blood sugar will remain above 120 mg/dL two hours after your meal.

I highly recommend you pick up a blood glucose meter if you have a thyroid and/or blood sugar problem. It’s the simplest and most cost-effective way to figure out how much carbohydrate is safe for you to eat. There are tons of meters out there, but one that gets a lot of good recommendations is the ReliOn Ultima. It’s pretty cheap, and the test strips are also cheap, which is where the major expense lies.

Finally, if you have poor thyroid function it’s important that you take steps to normalize it. As I’ve described in this article, the cycle works in both direction. Dysglycemia can depress thyroid function, but thyroid disorders can cause dysglycemia and predispose you to insulin resistance and metabolic syndrome.


Matthew July 23, 2010 at 6:49 pm

Hey Chris,
Thanks for the excellent post. I struggle with hypoglycemia, usually with a fasting blood sugar in the sixties, sometimes upper fifties, sometimes lower seventies. I don’t have much of a problem with handling high carb meals (no reactive hypoglycemia), but just have to eat often. I would like to keep my carbohydrate intake moderate for long term health reasons, and am curious what you personally think about moderate carb intake + high saturated fat, particularly in a hyper caloric environment ( I am trying to gain weight.) It is my opinion that the body is much better equipped to handle SFA in a low insulin and/or hypocaloric enviornment, but that when insulin is present or calories are above maintenance, there is the potential for poor cholesterol metabolism or reduced insulin sensitivity. I will note that it wouldn’t hurt if I increased my Cholesterol a little! (130 total)

Chris Kresser July 23, 2010 at 7:04 pm

I doubt high SFA + moderate carb intake would be a problem in your case, with numbers like those. But if you’re concerned you can simply monitor yourself using a blood sugar meter as I described. If your blood sugar is going above 120 two hours after meals, you’re exceeding your carbohydrate tolerance. And I agree that it wouldn’t hurt in the slightest if your TC went up. I’m surprised it’s that low on a high saturated fat diet. As you know, we often see higher LDL, HDL and TC on a high SFA diet, but lower triglycerides and small, dense LDL.

What I’m wondering is why your blood sugar is so persistently low. Have you investigated this?

Matthew July 23, 2010 at 7:11 pm

I’m not high SFA yet, thats the reason. Mostly monounsaturated, moderate protein. gluten free. I don’t know why blood sugar is so low. It is a little strange, but it seems idiopathic. Any ideas?

Chris Kresser July 23, 2010 at 7:18 pm

Assuming your diet isn’t poor, which it sounds like it’s not, adrenal fatigue and hypothyroidism are the two most common causes of hypoglycemia.  Have you had your thyroid checked and your adrenal hormones evaluated (using a saliva test)?

It’s possible you’re stuck in a vicious cycle where low blood sugar stresses the adrenals, which in turn suppresses pituitary function, which reduces thyroid hormone output, which wreaks further havoc on blood sugar and the adrenals, etc.

Probably worth finding someone who’s good at figuring this stuff out to work with.

Maria Minno July 24, 2010 at 1:20 am

This is great information, thanks.  Except the advice at the end is lacking.  The best way to normalize blood sugar is to eat plenty of high quality animal fats, rich in cholesterol, saturated fats, essential fatty acids and the fat soluble vitamins ADE&K that keep your hormones, adrenals, thyroid, and brain healthy.
I normalized my blood sugar and got rid of candida by going on a milk diet, and eating (drinking) nothing but raw milk for several weeks, followed by a period of adding bone broths, and then soups and stews into my diet.  It was very transformational.
My thyroid and blood sugar problems were further healed with important supplements in addition to a healthy nutrient-dense diet, which included fermented skate liver oil (similar to cod liver oil but higher in vitamin D) and iodine (Lugol’s and Iodoral).
I’m not sure whether your information comes out of books, from observing your patients, or from your personal experience.  However, in my experience, education, and observations, a person must do much more than tinker with their blood sugar levels in order to get well from serious chronic diseases like metabolic syndrome and thyroid disease.
If your goal is just any type of improvement, than fine, but there are so many other things that can be done to support complete or at least extensive healing, and no special equipment or lab tests are necessary.

Chris Kresser July 24, 2010 at 7:51 am


Please read my other articles on thyroid and nutrition. You’ll find that I’ve already addressed most of your points, and those that I haven’t yet will be addressed in future articles. This article is only one of an ongoing series.

I don’t believe iodine is a good choice for most people with hypothyroidism, which I explained here.

Byron July 24, 2010 at 5:22 am

Hi Chris,
just a huge thank you for your great blog. One of the fewest with really new informative and well researched articles.
I have hashimoto with low T3. Over 12 years LC and the last year nearly keto. Now trying some berries again. I´m also hypoglycemic with fasting BG under 50, postprandial 85 sans carbs, 115 con carbs. TG are 35, LDL 120 and HDL 199. I can´t eat more carbs because of allergies, intolerances and overeating problems. Basic is meat, fatty fish, yolks, chicory, cucumber, ghee, red palm oil and fish oil. Can someone be a really hypoglycemic without  feeling any symptoms?
Sorry for my english. Greetings from Munich.

Chris Kresser July 24, 2010 at 7:57 am


Are you on thyroid replacement? The two major causes of hypoglycemia (outside of poor diet, which doesn’t sound applicable to you are adrenal problems and hypothyroidism. If your T4/T3 has been normalized, I would investigate adrenal health. If your T4/T3 has not been normalized, I would attend to that. Thyroid hormone is just too important to the body to allow to be low for any significant length of time. With a fasting BG under 50 and a post-prandial (with carb) BG of 115 with carbs, it sounds like there may be an insulin issue. That’s a large spike in blood sugar after a carb rich meal. Although it’s still below 120, it’s a 65 point elevation from your fasting level.

Lethal Lee July 24, 2010 at 1:50 pm

“The problem is that cortisol also stimulates the sympathetic nervous system, causing a group of effects known as the “flight or fight” response. This response prepares us to defend against or flee from danger. It includes an increase in heart rate and lung action, increased blood flow to skeletal muscles and inhibition of organs and tissues not immediately involved in fighting or fleeing (such as endocrine and digestive organs.)”
Really? According to Endocrine texts it’s Ephidrine (Adrenaline) that does that? Having LOW Cortisol can cause huge Adrenaline spikes. And Adrenaline uses up Glucose so can cause precipitous drops in Blood Sugar levels.
Of course HIGH Cortisol is bad too. And low thyroid is a big stressor on th body & can cause you to overproduce Cortisol. High Cortisol can also cause Hyperglycemia.
Adrenals should be treated before Thyroid. It can be dangerous to do it the other way round.

Chris Kresser July 24, 2010 at 8:17 pm

Lethal Lee,

Sorry, that was a poorly written paragraph. I’m probably trying to do too much right now, writing this series with my state board licensing exams coming up. My brain is tired.

I’ve re-written it so that it’s more clear:

The problem is that cortisol (along with epinephrine) is also a sympathetic nervous system hormone involved in the “flight or fight” response. This response includes an increase in heart rate and lung action and an increase in blood flow to skeletal muscles to help us defend against or flee from danger. Cortisol’s role is to increase the amount of glucose available to the brain, enhance tissue repair, and curb functions – like digestion, growth and reproduction – that are nonessential or even detrimental in a fight or flight situation.

Chris Kresser July 24, 2010 at 8:21 pm

Both high cortisol and low cortisol are bad news for blood sugar. When cortisol is elevated it shuts down receptor sites and glucose can’t get into cells. Low cortisol will lead to reactive hypoglycemia and eventually adrenal exhaustion. I agree that adrenals and blood sugar need to be addressed before directly addressing thyroid – that’s one of the reasons I wrote this article.

Gary Wu July 24, 2010 at 2:29 pm

> When your blood sugar drops too low, the pancreas secretes insulin to get whatever glucose remains in the blood into the cells where it can be used for energy. Eventually this lowers the response of cells to insulin, creating insulin resistance.
It seems counter-intuitive to say that your body will secrete insulin in response to low blood glucose, since the immediate effect will be a further reduction of blood glucose levels.
My understanding of the rough mechanism is that in a hypoglycemic condition, cortisol and glucagon are secreted to raise hepatic glucose production.  At the same time, some mechanism (details of which I forget) is used to signal the muscle and adipose tissues to become temporarily resistant to insulin so that the increase in blood glucose is not immediately consumed, thereby bringing blood glucose levels back to normal range.

Elizabeth July 24, 2010 at 6:04 pm

Thank you, Chris, for showing the connection of low blood sugar and hypothroidism. I have had both since an early age and no doctor ever addressed the connection. I have to eat frequent meals, but I avoid carbohydrates. It’s my understanding that protein keeps blood sugar normalized, and it does for me. Just before bedtime, I have a glass of milk to hold me through the night, or I will wake up hungry after about five hours.

I used to get migraines from low blood sugar, or from any physical stressors. Now that I’m taking 4000 i.u. vitamin D3 daily, I haven’t had a migraine in months. I was getting them about every two weeks.

I did have a five hour test for low blood sugar about thirty years ago, when I was fifty. The test was given because of fatigue. I don’t remember the exact results, but afterwards I was so hungry, on the way home, I picked up brownies, went home and ate all with a cup of coffee. Needless to say, that threw me into bed with a massive migraine. I didn’t know any better at the time and wasn’t warned.

I’ve had very poor hypothroid management over the years. In the early years, doctors raised my medication in response to my symptoms, but in later years began to lower the meds because the tests showed too low TSH. Every time the medication was lowered, I gained ten pounds. That’s without increasing my calorie intake. When I got to 170 lbs, I started fighting the doctors to keep them from lowering my Synthroid any further. I had to go through a few doctors to finally find an endocrinologist who will let me stay on my present dose as long as I don’t show any hyperthyroid symptoms. My TSH is 0.01, but my free T4 and T3 are normal. This doctor did agree to adrenal testing, but unfortunatly not the saliva test.

I’ve tried dieting using high protein, low carbohydrate diet, but can’t lose weight. I still have some hypo symptoms, but overall I’m feeling balanced. I can’t afford to go all organic in my food choices, but do the best I can. And I avoid all sugar products, except for some dark chocolate, and eat mostly low carbohydrate. My snacking is always nuts and/or some protein and fruit.

From all the responses here, I see that this whole subject is quite controversial.

Marcia July 25, 2010 at 4:34 am

Chris – great post. Having spent a frustrating afternoon listening to friends talk about “sugar issues” and cholesterol numbers, I’m delighted to find your work and will send the website info on to them. I really appreciate all the detailed information, and so, I hope, will they.

One small caveat: people could be confused by the following (non-medical) issue:

“Your body is genetically programmed to recognize low blood sugar as a threat to survival. Severe or prolonged hypoglycemia can cause seizures, comma, and death.”

Should be coma, no? I seriously doubt that anyone has been done to death by punctuation!


guzolany July 25, 2010 at 6:58 am

>When your blood sugar drops too low, the pancreas secretes insulin to get whatever glucose remains in the blood into the cells where it can be used for energy.
Pure nonsense. The body’s goal is autoregulation and not suicide through even worsened hypoglycemia… Silly mistakes like these really threaten your image as the well informed “science writer” you claim to be. You would be very well advised to correct this immediately! Gary Wu already gave the necessary hints above.
Cheers, guzolany

Phoenix July 27, 2010 at 4:06 pm

Hi Chris
Great blog! I’m a long time reader, first time commenter. I have been struggling with a number of problems and thought it would do no harm to ask you, although I understand you are studying profusely and looking forward to a vacation in mexico :-)

Basically my scenario is thus: I got diagnoised with Hashimoto’s by my naturopath approx. 4 years ago. (TPO was 900). I was already wheat free and mostly gluten free by then as I have severe digestive reactions to those foods. She put me on a bio-identical hormone and for the next 18 months or so I have the highest quality of life I had ever had. I was able to finially lose weight (with careful food monitoring…nothing is for free) and felt like a normal person again after years of flailing with symptoms and no diagnosis.
Then the government here in Canada took away naturopath’s right to prescribe medication, so I ended up going through my primary care MD to get onto more main stream synthetic drugs. In the interm I stopped cold turkey the old meds…my TSH shot up and my T3 and T4 plummetted. I was able after many month and a fairly high dose of meds to get my T3 and T4 into “normal” range. I now take Thyroid (by Efra) at 180 mg, and Cytomel 50 mcg. daily

But unfortunately in order to achieve this symptom free state I had to keep my TSH at 0.01…fast forward a couple of years later and I have been diagnoised with Ostepenia as evidenced on a recent bone scan. Also I have now been in menopause for months…I’m 32… estrogen apparently. I should mention I am now into my third year of training for Ironman competitions.

In the past couple of months the old problems have returned and I have gained gads of weight. I actually had been testing my blood sugar prior to this post so was pleasantly surprised. It isn’t perfectly controlled. But I wake with it in the high 5′s (5.7 or 5.8 on average). I can drop it to under 5 with intense or very long exercise (6 hour ride). I can also spike it to 8.5 if I drink anything with sugar in it (like a mocha) on an empty stomach.

If I don’t eat carbs and have nuts and protein my blood sugar stays below 6 even after eating.
So my question is this: since my current T3 and T4 are now well below normal and continue to drop at every test, and my TSH remains at 0.01 it is pretty clear that adding meds to this isn’t helping, and the low tsh is causing bone loss. How do I get myself a) off the meds and b) converting t4 to t3, or whatever it is that I need to do on a cellular level.

Other numbers of interest
Cholesterol 3.77
Triglycerides .3
HDL 2.35
LDL 1.28
(all considered LOW…sorry these are canadian measurements in mmol/l)
free T4 9.0
Free T3 1.0

Chris, any thoughts or opinions will be greatly appreciated. I read Dr. K’s book, but to be honest much of it went over my head in terms of trying to figure out which dominate I am, and there are no practictioners in Canada.
from Canada

Chris Kresser July 27, 2010 at 5:44 pm


I wish it were possible to advise in a situation like this, but the complexity of thyroid physiology (which you got a taste of in Dr. K’s book) makes it difficult.

My guess from reading your post is that your adrenals are taxed from training and that has thrown your blood sugar and hormones out of balance. I’m guessing you have high cortisol from your training regimen, and possibly some underlying inflammation, both of which are dampen receptor site sensitivity. That could explain why you’re not responding as well to your meds, even at doses high enough to severely inhibit TSH.

Also, your total cholesterol is very low. Has it always been this way? Sometimes this can simply be genetic, and nothing to be concerned about. However, if it’s induced by your training and/or diet, it’s probably not healthy. Cholesterol levels under 160 mg/dL carry a higher risk of heart disease, depression, and other mental health issues. Your triglycerides are the lowest I’ve ever heard of. While most doctors would be patting you on the back, I don’t think levels that low are physiologically normal. Oddly, we might expect to see a TG count that low with hyperthyroidism. But it also happens with malabsorption syndromes and extremely low-carb diets. Your LDL is also very low, and it raises the same concern for me as your total cholesterol and TG reading. Your HDL, however, is in an excellent range.

It’s very likely you won’t be able to get off meds. I’ll be writing an article about this in the future, but it’s my believe that Hashimoto’s patients with persistently low T4/T3 readings need replacement. Thyroid hormone is just too essential to the body to be deficient in for any significant length of time. But hopefully by improving receptor site sensitivity and addressing the underlying metabolic imbalance, you’ll be able to reduce the dose you need to have the same effect and get your TSH back into a normal range.

Overall I’d say you’re experiencing a metabolic derangement probably related to overtraining/stress. The key will be supporting your adrenals, regulating blood sugar, eating plenty of saturated fat and cholesterol, bringing your cortisol levels down and reducing inflammation. Perhaps you could find a practitioner that’s willing to work with you on the phone.

Elizabeth July 27, 2010 at 5:40 pm

Wow, Phoenix, your system is really out of whack. You need some good care by an alternative type practioner, or at least someone very knowledgable about nutrition, plus an endrocrinologist who knows what the heck he is doing.

Phoenix July 27, 2010 at 7:03 pm

Hi Chris,
Thanks for the quick response. My Cholesterol has always been low, and yes my doctor does comment on how awesome it is…although my naturopath doesn’t think so, she says that with no cholesterol I don’t move hormones in my body either. I also have very low blood pressure 97/49 avg. and always have. I don’t get dizzy easily either. When I first got sick the only thing that made me feel remotely normal was training…I had a 24 hour test done…but haven’t had the Saliva done.
Do you think acupuncture for encouraging the HPA axis?
I am done with Ironman in 4 weeks so my goal is to focus on my health and getting the TSH up. I haven’t been adhering to a low carb diet as a result of training…just can’t get the 20 plus hours a week in on pork chops, but I feel good when I can low carb it, and don’t get me wrong I don’t eat terribly either. I can count on one hand the number of times I have eaten out this year and have a garden I am quite proud of and Im not scared of a big steak. I consider sweet potatoes and an extra piece of fruit cheating. When I can get things together I weigh about 124 pounds and right now I am at least 20 pounds heavier…all gained since April. (while training and eating properly).
If you could recommend someone to work with who would that be? Aside from fish oil, anything else I could do to raise my cholesterol?
Thanks again!

Chris Kresser July 27, 2010 at 7:23 pm

As your naturopath may have told you, cholesterol is the precursor to all sex hormones in the body. If you don’t have enough cholesterol, you can’t make hormones.

Saturated fat will raise your LDL (increasing large, buoyant LDL and decreasing atherogenic small, dense LDL). In 30% of people eating cholesterol will raise in in the blood, but in 70% of people it has no effect. I’d suggest eating 2-4 eggs a day. Fish oil will likely lower – not raise – your cholesterol.

Acupuncture is great for regulating the HPA axis.

Try this to find a practitioner.

Phoenix July 27, 2010 at 8:59 pm

ok, I’m cool with eating eggs but have cut back consumption of eggs and nightshades due to Cordain’s work in Paleo nutrition with people with auto-immune disorders.
I think I am the 70% that won’t be able to raise my cholesterol with diet….
So no more fish oil? I googled foods with high saturated fat…and as you are probably well aware I got nothing but the SAD pushed…so crazy. (I’ve read good calories, bad calories, so I am not buying their junk).
Other suggestions for reducing inflammation? I took the ALCAT two weeks ago and showed a reaction to 50 different foods. (in addition to what I already knew of wheat and dairy).
I think my immune system is stronger than terminator…I never get sick….and my body perceives everything as a threat. including sadly my thyroid…..

Chris Kresser July 27, 2010 at 9:06 pm

If you’re concerned about a potential reaction to eggs, limit your consumption to yolks. When people are sensitive to them, it’s almost always to the whites.

EPA & DHA are both anti-inflammatory, and can help improve hormone receptor site sensitivity, so I wouldn’t cut it out. Good sources of saturated fat are butter, cream, ghee, coconut oil, palm oil and beef tallow. I respect Cordain and his work, but I don’t necessarily agree with him on dairy – especially the milk-fat products like butter and cream, which are exceptionally nutrient-dense and healthy, especially for someone in your predicament. My sense is you need more nourishment, and it’s hard to come up with more nourishing foods than egg yolks, butter, and cream.

I don’t believe in the food allergy tests. There are a number of problems with them, and I don’t think they’re accurate. The only way to really determine food sensitivities is an elimination/provocation protocol. Even then, most people find that when they heal their gut, they are able to tolerate foods they were sensitive to before.

I’d suggest investigating the GAPS diet ( as a means of addressing some of your issues. It’s the best method I know of for restoring gut mucosal barrier integrity and reducing intestinal inflammation.

Chris Kresser July 27, 2010 at 9:15 pm

Just want to emphasize again, though, that my sense is reducing stress and balancing your adrenals is going to be the key to your recovery. When I say stress, I’m using the term in a broad sense – physiological (overtraining, leaky gut, inflammation, etc.), psychological and emotional. Stress causes something called the “pregnenolone steal” (Google it to learn more), where pregnenolone, the precursor to all sex hormones, is preferentially diverted to cortisol production. This is an evolutionary response. Cortisol raises blood sugar levels so we can produce more ATP (energy), which is necessary in times of stress (fight or flight). But if this happens persistently, there’s no pregnenolone left over to make the other vital hormones (like DHEA, estrogen, testosterone, aldosterone). This is probably why you haven’t had a period for several months.

Tracee July 28, 2010 at 2:15 pm

Great Post!! I have to eat mostly SCD. I have Celiacs and Crohn’s, but even gluten-free grains give me fatigue and sugar cravings. I’ve been wanting to figure out what my issue with grains is, and have been tempted to get a glucose meter after reading Blood Sugar 101. I had no idea my thyroid could be involved in this too. In fact, before your articles I really did not know much about the thyroid. Wow, I wonder how many thyroids the food pyramid has destroyed!

Elizabeth July 28, 2010 at 5:14 pm

My thyroid was destroyed some time ago, and I depend on Synthroid. Years of stress, also wore my adrenals out, and doctors just pooh pooh that when I suggest it to them. If you don’t have a measurable disease, you get no help from almost all doctors. I say this from years of having many doctors, always the same results.

Sarah August 2, 2010 at 3:57 pm

I’m so confused!!
I have also been curious about my blood sugar levels as when I was pregnant the second time and had the Oral glucose test at 28 weeks.  It showed I was hypoglycemic.  But no one ever has checked me not pregnant.
So…I bought a glucose monitor today.  Ate a large carbohydrate meal and tested one hour after eating….it was 4.3 mmol/L!  Which translates to 77.5 mg/dL!  That’s one hour after a heavy carb meal of 93 g of carbohydrate.
What gives?  I am going to test in one more hour to see what it is at 2 hours post prandial…

Chris Kresser August 2, 2010 at 4:15 pm

Sounds suspicious. When we look at blood sugar, patterns are more important than single readings. Take your fasting BS for a few days in a row, as well as 1- and 2-hour post-prandial readings with different types of food. Then we’ll see what pattern emerges. If you are persistently hypoglycemic, you definitely need to address it.

Sarah August 2, 2010 at 6:09 pm

thanks.  Was 7.1 two hours post prandial…which is 127.8 mg/dL.  Which I would say is on the high side…but maybe not after such a heavy carb load.  I will take it fasting in the morning the next few mornings and then some different meals too.  Normally I don’t eat that many carbs at all…but I figured it would be interesting to see how my body is “coping” with that many carbs.
Thanks again!  Your blog seriously rocks!

Chris Kresser August 2, 2010 at 6:12 pm

128 is high for 2-hour.  You want it to be under 120 2-hours after.  If it’s higher than that, it means you ate more carbs than you can tolerate.  If you also had a significant amount of fat at that meal, it probably slowed down the absorption of the carbs which is why your blood sugar was still low one hour after the meal.  Take another reading at 3 hours out next time you have a meal like that.  I suspect it will still be high.

Sarah August 2, 2010 at 6:23 pm

I’ll try that for sure!  Man the body is crazy interesting!

Lynn August 2, 2010 at 8:00 pm

Phoenix – Your adrenals do sound very fatigued, HOWEVER it could also be the ERFA. I found it to be an inneffective med for my body and I had to switch back to the Thai Thiroyd. It basically made me very hypo again. This could be an issue for you too. If you are looking for support or advice, the forums at are excellent.

Sarah August 3, 2010 at 3:54 pm

so 102.6 mg/dL first this this morning (fasting).  Then 92, 3 hours post prandial a 14 g carb lunch.

Chris Kresser August 3, 2010 at 3:57 pm

A normal fasting blood sugar is 85 mg/dL or less. Doctors say anything under 100 mg/dL is normal, but plenty of research shows that fasting blood sugar in the mid 90 mg/dl (5 mmol/L) range often predicts diabetes that is diagnosed a decade later. In your case there is definitely a blood sugar imbalance going on based on the readings you have shared.

Sarah August 3, 2010 at 4:00 pm

I’m going to keep taking them and recording it so I can show my dr.  ugh…I think I need diabetes like I need a hole in the head…

Phoenix August 3, 2010 at 4:36 pm

So it should be under 5 mmol/l ? Mine is always 5.2 or higher (as high as 5.6) first thing in the morning, it can go up a couple of points with moderate exercise, ie an hour of jogging, and it goes down into the 4′s if I kill a workout (go with hard intensity) and feel tipsy afterward.
I have been eating lettuce as my only carb and lots of fat and a little protein over the past couple of days and I still get my blood sugar at 6 mmol/l 2 hours post.
Although yesterday it never went about 5.4 all day.

Testing is very thought provoking I can say that. Like the first week I got it, I had a coffee that had sugar in it, and it went up to 8.5 or something ridiculous…no more drinking calories for me. The bio feedback is good for me.

Chris Kresser August 3, 2010 at 7:14 pm

It should be under 85 ng/mL when fasting. If it’s not, it indicates blood sugar dysregulation. That doesn’t mean diabetes, but keep in mind diabetes develops slowly over time. It’s not like catching a cold. So identifying imbalances like this early is an important step in preventing them from developing into full-blown diabetes later in life.

As I’ve written in this series, it’s not just about diet. The adrenals and the immune system must be addressed.

Phoenix, yes, balancing the adrenals is trickier when autoimmunity is involved. As you pointed out, certain botanicals have a stimulatory effect on the Th1 system, which is often overactive in Hashimoto’s patients. This is why it’s important to find someone to work with on this stuff. I wish it was simple enough to just write a couple articles on and give people enough information to treat themselves. Unfortunately, thyroid disorders are far too complex and multi-factorial for that. And I wish it was easier to find practitioners who are well-versed in functional medicine. I’m doing the best I can to get the word out, but there is a definite lack in this area.

Denise August 5, 2010 at 9:41 pm

I am a 46-yr-old female, recently diagnosed with multi-nodular goiter but have “normal” blood results (including autoimmune); needle biopsy of a large nodule which I was told revealed “nothing abnormal” (although my mom, who is a physician, said didn’t look like a very good sample as it was “mostly blood with a few follicular cells”). I have what I feel are hyperthyroid symptoms upon waking (racing thoughts, OCD, fast heartbeat, palpitations) and hypothyroid-related symptoms throughout the day (lethargy, constipation, depression, low Vitamin D, unexplained high cholesterol, long periods, hot flashes). The tightness in my neck from the goiter is very uncomfortable. My question is this — After reading your articles I’m going to try to address leaky gut, gluten intolerance etc. — Is there a chance that will help me with the NODULES, or are are those only going to go away with thyroid hormone and/or surgery?
I’m SO glad to have found your site.
Thank you! Denise

Aaron B. August 8, 2010 at 6:44 pm

Hi Chris,
There’s a lot of good stuff to think about here.  A couple questions:  Do you think going too low-carb can be a problem for people with thyroid/adrenal issues?  Also, do you really think overconsumption of carbs causes insulin resistance by itself?  I used to think that, but reading about the Kitavans and other societies that eat a high-carb (unrefined) diet without any metabolic disease is making me think there must be some other factor (inflammation, nutritive wasting by refined carbs, stress) that kicks off the insulin resistance, maybe in combination with carb load.
My background:  After a bad bout of mono and a stretch of trying to combat fatigue and long work hours with caffeine and ephedrine, a chiropractor/kinesiologist diagnosed me with adrenal fatigue about 15 years ago, and told me to lay off the stimulants and ‘white’ foods: white sugar, white flour, potatoes.  I did for a while, and felt better and lost some weight.  Of course, I drifted back to a SAD diet, and ever since I’ve had problems with fatigue and stress.  (I’m naturally introverted anyway, but now any sort of social stress leaves me needing a day to recover.)  I also gradually gained weight, and discovered low-carb to combat that.  It seemed to help with the fatigue and mood too, but after a few years that effect (and the weight loss) lessened.  But I stuck with it because a ‘normal’ diet would drive my BG over 120 (and junk food like potato chips would drive it to 180+).
But now I’ve been reading about how going too low-carb long-term might be a problem for people with adrenal issues, because the adrenals have to produce more cortisol or other hormones to break down protein for sugar.  So instead of over-working your pancreas, you end up over-working your adrenals.  Does that make sense?  Does it mean I should go just low enough to keep my post-prandials under 120, and no lower?  Should I eat more carbs spread out in small snacks, to keep BG supplied without the help of the adrenals?  Would it be helpful to get an adrenal test done to see whether my cortisol is high or low, and that sort of thing? Also, my TSH is high (4.280), but my T3 and T4 are in the middle of their normal ranges.  That, together with your articles, also has me thinking about gut inflammation, and all the omega-6 I got over the past few years from snacking on nuts and peanut butter to stay low-carb.
Sorry for all the questions, but this seems like the one place where all my issues are being discussed.  Most places focus on one thing, like adrenal health, to the exclusion of everything else.

Chris Kresser August 9, 2010 at 6:15 am


I am aware of the Kitavans and yes, I think the problem is more related to refined carbs than starch. Unfortunately, that’s predominantly what Americans eat. Also, once dysglycemia sets in, even natural starches can push blood sugar to unhealthy levels. I’ve seen this over and over by asking patients to measure their blood sugar after various meals.

I have heard anecdotal reports that a very low-carb diet can cause hypothyroid symptoms and adrenal issues, but I haven’t seen that firsthand. There are some physiological mechanisms that make it plausible, which is why I don’t recommend a VLC diet over the long term for most people. Steps must be taken to restore insulin sensitivity along the way, with the idea of being able to reintegrate some healthy carbs later. There’s no hard, fast rule though.

It’s super important to keep your BG below 120 post-prandial, and I personally would prioritize that and then focus on supporting the thyroid and adrenals. Testing your cortisol (using the salivary profile offered by Diagnos-Techs) would be worthwhile to see where you stand there. High TSH on its own is hypothyroidism, even according to the mainstream definition, regardless of your T4 and T3 levels. That needs to be addressed, and my guess is your blood sugar and adrenal issues will improve when you do that (and vice versa).

Aaron B. August 9, 2010 at 2:27 pm

Thanks, Chris.  I guess I need to do some reading on treating hypothyroidism as high TSH, and see about getting that cortisol test.  (I know you’ve written more stuff on thyroid than I’ve read so far, so I won’t ask you to repeat it here. :-) )  I’ve already decided to cut out gluten, since my wife had to, and it seems like a good idea for anyone.  I’m going to test my BG more often to figure out how much non-refined carb (probably mostly potatoes) I can eat without going over 120 BG.  Stuff I’ve read over the years on healing adrenals, like the book Adrenal Fatigue, always said not to go too low carb, but they never really said why, so I just ignored them since I also wanted to lose weight.  Maybe I need to focus on the hormones first and worry about weight later.
Incidentally, what do you think of the raw milk diet for adrenal fatigue and/or hypothyroid?  We just did that for about 10 days and my BG stayed surprisingly good, never exceeding 110.  We basically stopped out of boredom, but I’d do it again for longer if I thought it’d help.
Thanks again.

jo September 8, 2010 at 12:32 am

I would like to know what kind of meal is best eaten before checking post prandial blood sugar ? Im sure what you eat affects your readings,and eating what you normally eat may not cut it. Should one include sugar ? Or how many grams of carbs should that meal include ?

Chris Kresser September 8, 2010 at 7:41 am

The whole point is to eat what you normally eat and see how it affects your blood sugar. If it goes too high, you know you’ve eaten too many carbs. If it doesn’t go too high, that suggests you’re able to tolerate the amount of carbohydrate the meal contained. This doesn’t mean you are free to eat anything as long as it doesn’t raise your blood sugar. It’s only one criterion.

andy September 11, 2010 at 6:08 am

Chris, thx for great info.
Regarding eating high fat diet and haveing a high blood glucose and just want to say that high  fat levels in the blood stream (TGL)  can reduce insulin sensitivity and therefore eating low carb high fat can still make your blood glucose hight.
I notived myself, if i eat lost of nuts (over 100 g of fat) in the evening or other fats liek coconut oil my fasting glucose levels goes up 5 or even high, whilst  normaly is around 4.7 – 4.7.

simona September 15, 2010 at 9:30 am

Hi Chris,
Thanks for all your posts.
Do you think that somebody with potential adrenal and thyroid problems should eat 3 meals a day instead of the usual 2 meals recommended for IF? If the glycogen stores are not re filled the same day the liver is going to make glucose from protein and that taxes the adrenals so a certain amount of carbs is recommended too. Do we need the 400 kcal that Paul Jaminet recommends?

Chris Kresser September 15, 2010 at 9:36 am

See this comment I just wrote on Paul’s blog on this exact question. The short answer is that I’m wary of IF for people with hypoglycemia, adrenal and thyroid problems. Some argue that IF can have a blood sugar stabilizing effect, but I’m not convinced of that in this particular patient population. I’ll be curious to see how Paul responds. Yes, I think 400 kcal of glucose is a good target for those with blood sugar issues.

Ann October 27, 2010 at 4:34 pm

I just read this and I am freaked out. I have had a thyroid condition for 13 years and i have had it monitored regularly. I started feeling weird and my hair was falling out. So I went back to doctor, and my thryoid was like 8 when it was supposed to be 1 or 2. She also said my fasting glucose was 102. I have never had glucose problems. I am a very health eater(ridiculously so) and am thin. I am normal weight and have always been normal. I am 45 and I had two kids and never had gestational diabetes. I was also taking a lot of fish oil for dry skin. I have heard that this can impare fasting blood glucose. I don’t want diabetes. I went back to the doctor once and my thyroid meds have to be bumped up again, and glucose was borderline. What can I do to avoid diabetes?

Chris Kresser October 27, 2010 at 5:10 pm

Ann: check out my series on diabesity, which is still in progress. If you subscribe to my blog for email updates, you’ll get all the new articles as they’re published. You can do that on the homepage.

lynn October 28, 2010 at 5:13 am

Ann – What thyroid med are you on? Dosing shouldn’t be based on TSH, which is what your doc is doing. Instead, you need to look at the Free T4 and Free T3.

I’d advise you to check out

Em February 8, 2011 at 2:09 pm

I’m very confused about my blood sugar. I had fbg done at my Md’s and it was 103″ and somehow he said that was normal and I looked at the lab ranges and the lab he uses defines normal unto fbg of 110! Weird.

Also, i have eaten lower carb for the past year plus, and 1 year ago at the doctors my fbg was LESS, 94, prior to trying lower carb. So I bought a meter and tested at home and found my fbg was 105 one day, and tested a few times and it is never below 95. But, 2 hours after eating a breakfast of eggs, bacon and white potatoes my bg was 85. What gives? I ate carbs and bg was normal a couple hours later, but my fbg is generally high.

My tsh is ok, 2.3, the doctor didn’t do a hasimotos test as he thinks it’s very “rare”.

Chris Kresser February 8, 2011 at 6:13 pm

Hashimoto’s is far from rare. 9 out of 10 women with hypothyroidism in the U.S. have it.

You’re right: blood sugar is confusing. But your numbers are typical for a low-carb dieter. I’ve explained it here.

Jo February 14, 2011 at 9:04 pm

Hi Chris:

Great information. I have both insulin resistance and low thryoid right now. I am currently on time-release T3 therapy (Wislon’s protocal) which has worked well for me two other times in the past ten years, but this time, (the first that I knew I had blood sugar issues too) I have not responded so well to the T3. I did buy a glucometer and have been keeping very careful records, cutting carbs, measuring and recording every bite, and exercising — but my fasting blood sugars seem to increase everytime that I change my T3 dosage — up or down….is this as I am starting to suspect, because of the changing T3 amounts — or could there be something else going on here that I need to consider?

The other thing I am wondering about — I have all but cut fruit out of my diet — having it only in a morning protein shake, after which my blood sugar is usually in the 80s (lower then when I wake up!) But I do miss it sooooo much. So I succumbed twice in the past week to an apple late in the afternoon and was shocked to see my blood glucose spike after words — BUT it seemed to spike much more the day following my liberal use of coconut and cashews — more fat than I typically have….when I get my t3 dosage figured out and stabilized I plan to do a controlled experiment — fruit following a day of very low fat eating and fruit following a day of higher fat eating and see if there is a difference — what do you think I will find here?


lynn February 15, 2011 at 8:04 am


If I raise my thyroid too fast I get reactive hypoglycaemia. I found this out a NUMBER OF TIMES in my eagerness to get my thyroid right and my life back. Raising too fast messes with one’s blood sugar as it is harsh on the adrenals and they are involved in blood sugar regulation.

One of the criticisms of Wilson’s is that it works via very fast raises and can thus lead to symptoms such as you describe. It also taxes the adrenals. If you have high RT3, I’d suggest you check out Nick Foot’s website and increase T3 in a slower way. If you have just plain ol’ hypothyroidism, I’d suggest you check out

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