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Reverse T3 Hibernation Effect

Going Low-Carb too Fast May Trigger Thyroid Troubles and Hormone Imbalance

Don’t be fooled by the bread demons, you CAN be healthy on a low-carb diet

If you’ve been turned on to the low-carb Paleo diet craze, you may have noticed increased energy, better digestion, happier mood, and a shrinking waistline. Good for you. But some folks who’ve taken the Primal leap—particularly those who were previously on a high-carb diet—have been faced with unexpected side effects waving them back to the world of bread, sugary fruits and sweet potato casserole.

Interestingly, these side effects include a wide range of symptoms that are nearly identical to symptoms of severe thyroid hormone deficiency. More interestingly, lab tests often show normal or near-normal thyroid function. More interesting still is that these symptoms seem to only be relieved by adding back carbs into the diet, sometimes upward of 300 grams—a level I consider to be very likely to harm.

Why is this happening? Is it that low-carb simply doesn’t work for everyone, or is something else going on?

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The low-carb conundrum just so happens to be an issue I’ve been pondering since reading about the controversy over safe starches. Recently, a couple of pieces of the puzzle fell into place that I think add up to at least one explanation for the debilitating symptoms and offer a method for anyone going low-carb to do so without problems.

Here’s what I discovered about those with thyroid problems.

Abrupt Change May Be too Much For the Thyroid

People who run into trouble going low-carb seem to follow a pattern. They follow any number of diets from SAD to vegan before making a relatively abrupt switch to a low-carb (often less than 50 gm) diet. At first they lose weight as hoped, but then, instead of feeling more energetic from their weight loss, they develop fatigue, sometimes accompanied by symptoms of low thyroid function, including cold extremities, hair loss, and digestive problems. Only by consuming more carbs again can they reduce these symptoms.

Because their fatigue and other symptoms are classic for thyroid malfunction, many will get their levels tested, only to come away confused when the tests health practitioners typically order (TSH and T4) come out normal.

Those who get more extensive testing may get a test called reverse T3, or rT3 for short. These are often abnormally high, leaving them to believe they have found the root of the problem. Some are given a prescription for T3 in hopes of regaining energy, and the intervention seems to help, at least a little.

Reverse T3 is a kind of chemical opposite of regular T3, a mirror image compound called an enantiomer. Reverse T3 has opposite effects of T3 and has long been associated with a set of symptoms aptly called hibernation syndrome—fatigue, weight gain, and so on. If you have suffered from severe hypothyroidism, you may have gone through times when you felt like you really just want to crawl away to a quiet place and rest for a long, long while. Your body was telling you to hibernate.

In addition to making our energy go dormant, high rT3 is also associated with increased levels of LDL, often in the 200s.

Interestingly, those who have added carbs back into their diet and have gotten retested find that their levels of rT3 have gone down without additional T3 supplementation. What’s more, if their LDL was high, adding carbs back to the diet also solved that problem as well, completely counter to the idea that carbs drive insulin which increases LDL.

I have to admit that though I have cared for thousands of people following low-carb diets, to my knowledge, none ran into this problem, so I paid very little attention to the issue with rT3. Only when I started reading about people suffering from thyroid side effects from following low carb did I started seriously thinking about that pesky little molecule. I wondered what it was supposed to be good for: Why would nature program our biology to manufacture a compound that seems to do little other than make people miserable and potentially clog our arteries?

The reason low carbing triggers thyroid changes

In doing research on rT3, I ran into a fascinating article on a group of little-understood compounds called thyronamines (pronounced thigh-row-na-meens). The key to understanding rT3, and unlocking the relationship between carbohydrate consumption and thyroid function, may lie in these newly discovered compounds.

Thyronamines have powerful effects on energy metabolism

Studies performed in 2010 showed that injecting thryronamines into the belly cavity or brain tissues of experimental animals cause the following physiologic and behavioral changes:

  • Impaired ability to utilize sugar as an energy source
  • Insulin resistance
  • Lowered basal body temperature
  • Weaker than normal heart contractions
  • A marked decline in activity (We can’t ask the lab animals, but presumably, this would be induced by what we would describe as feelings of extreme fatigue)

Sound familiar?

Upon injection, the effects begin within minutes and last 8-12 hours.

And here’s the punchline: Thyronamines appear to be manufactured from that go-to-sleep hormone reverse T3. We can’t yet test you for high levels of thyronamines, but in testing your rT3, we are testing for the precursor of thyronamines. And I expect that, when studies are done in people, we will discover that high blood levels of rT3 do indeed correlate with high tissue levels of thyronamines.

I think this research is vitally important and that we will be hearing more about thyronamines in the future. But we are still left with a very important question that remains unanswered: What do we do about it?

For an answer, we can look to nature and find what I call The bear in the woods theory.

Changing from carb-burn to fat-burn demands new metabolic machinery

The bear in the woods theory suggests that it is the relatively sudden change from high carb to low that flips the switch.

Bears are omnivores, just like humans. And, of course, bears hibernate. Understanding the variations of a bear’s diet throughout the year helps us to understand why biology has built into our mammalian metabolism a sensitivity to changes in carbohydrate consumption.

Imagine you are a bear living in Yellowstone national park. It’s late summer, and the salmon runs are gone, the grazing animals born in spring have now grown too fast for you to catch, the grubs under the rocks are all hatched, and pretty much all that’s left, aside from campground garbage, is nuts and berries. Plucking ripe berries off a bounteous shrub is far easier than cracking nuts, so you gorge on berries. In a few weeks, though, the berries are gone, and there’s very little food left. That’s okay, because the abrupt decline in carbohydrate consumption is accompanied by increased reverse T3 and increased production of thyronamines, which makes you feel exhausted. Thanks to all the weight you gained, you are now so well-padded with cushy fat that you think you could just crawl into a cave somewhere and sleep for a long, long time.

Research in humans shows that, just like bears, our thyroid hormones are influenced by major changes in the amount of carbohydrates consumed.

For some, an abrupt decline in available glucose may trigger an atavistic hibernation reflex, which will trigger the conversion of a thyroid hormone called T4 into something other than the normal T3, namely into the reverse form, rT3. rT3 then gets converted into thyronamines and causes all the symptoms of low thyroid function without significant deficiencies of thyroid hormone showing up on lab tests, leaving people to worry there is something incredibly wrong with their hormonal function.

 How do you enter fat-burning mode without going into hibernation? The solution is gradual change.

If you have gone low carb successfully, you have accomplished a major change in your metabolism, one that involves turning on scores of enzymes your body has not needed or used for a long time, decades in some cases. Not everyone can accomplish this overhaul in time. Those who can often continue low carb for life with great success. But those who cannot accomplish all the necessary changes flip the hibernation switch, and increase production of rT3 and thyronamines, which causes crushing fatigue and may lead to intense carb cravings in order to turn off the hibernation switch again.

For these people, an easy way to avoid flipping the hibernation switch and reduce carb cravings may be to simply make a more gradual reduction in carbs rather than an abrupt one.

Atkins, who advocates an abrupt switch to less than 20 gm per day, seems to have been aware of this problem, and in fact, in his writing, he warns people they may experience fatigue in the first few days or weeks after going very low carb. Unfortunately, for some people, the fatigue never improves, and they give up on low-carbing altogether.

 Instead of giving up, I believe you can try again but next time don’t go cold turkey on carbs. Cut back gradually.

Incidentally, none of my patients reported feeling worse when they went low carb. I suspected it had something to do with the fact that I introduced them to low carbing one meal at a time beginning with breakfast. I made this recommendation simply because I didn’t have time to go over everything with them in one visit. I only had time to give them ideas for one meal, and had them start by cutting carbs from breakfast because that is the time of day we are most able to switch our dormant fat-burn enzymes from off to on.

Bottom line: If you jump into the Paleo (or any low-carb) program and hit a brick wall because of side effects, instead of giving up on low-carbing for good, add back your carbs until you feel better again and then try cutting down again, but go slow to give your body the time to adapt to the idea. This way, your low metabolism can gear up to give you the fat-burning benefits of hibernation without having to take the four-month winter snooze.

Come out of the Carb-Cave and into the light of a rejuvenating diet!

With over two decades of clinical experience and expertise in genetic and biochemical research, Dr. Cate can help you to reverse metabolic disease and reshape your body.

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This Post Has 201 Comments

  1. […] Low carb has been all the rage for quite some time. We stumbled onto the whole thing about 3 or 4 years ago when my hubby had some serious health issues. Initially the greatest warning I could find were about ketosis. As time passed I started struggling with some imbalances and I started really digging into it. Turns out, low carb too quickly, too much is really really really dangerous. Ketosis is the least of your problems so take it very slowly. In this article Dr Cate touches on thyroid problems that could be triggered by going low carb too quickly. But go read for yourself. Dr Cate on low carb and the thyroid […]

  2. You specifically mention folks who develop rT3 but have no other blood lab signs of hypothyroidism. What about someone who has hypothyroidism PRIOR to going low carb, then 18 months in, his/her rT3 to free T3 ratio is terrible? I believe all of this was tested prior to 2009 (the rT3 ratios before), but I’m not certain, as I don’t have ready access to those records. That being said, I do have evidence showing TSH issues (and negative antibodies tests – both types) and treatment with T4 medication before I pushed for rT3 testing this time, and got numbers showing that I needed treatment there, too.

    I’m an all or nothing person – and always have been. I can’t (easily or successfully, so far) do moderate carbs without flaring up my insulin resistance to the point I faceplant into ALLTHECARBS… It’s frustrating. I started low carb at the behest of my endocrinologist on 1/15/15, aiming for 50 grams of carbs. I was close for that first month, then realized I was closer to keto levels, so I took that leap on 2/18/15. I lost weight steadily until the end of March/beginning of April, and then I started gaining. I’ve managed some of that gain again, but have yet to find my footing solidly again as far as losses. I did take some time off my low carb plan around the holidays (about a total of 30+ days, but not all in a row). Other than random 100 grams of carb days, I’ve been back low carb since 1/25/16, but I’ve not lost more than 5 pounds in that time, though I have gotten back down my previous size jeans I was in prior to going off plan.

    I’m just curious specifically how the rT3 issue can be present with and without underlying other thyroid issues – and whether it’s still related to this issue…of needing to up carbs, etc.

  3. […] Going Low-Carb too Fast May Trigger Thyroid Troubles … – At first they lose weight as hoped but then, … which will trigger the conversion of a thyroid hormone called T4 into something … If you have gone low carb … […]

  4. […] References: – Vreugdenhil, A. C. E., Snoek, A. M. P., van ‘t Veer, C., Greve, J.-W. M., & Buurman, W. A. (2001). LPS-binding protein circulates in association with apoB-containing lipoproteins and enhances endotoxin-LDL/VLDL interaction.Journal of Clinical Investigation, 107(2), 225–234 – Horton, J. D., Cuthbert, J. A., & Spady, D. K. (1993). Dietary fatty acids regulate hepatic low density lipoprotein (LDL) transport by altering LDL receptor protein and mRNA levels. Journal of Clinical Investigation, 92(2), 743–749 – Tosco A et al. Molecular bases of copper and iron deficiency-associated dyslipidemia: a microarray analysis of the rat intestinal transcriptome. Genes Nutr. 2010 Mar;5(1):1-8. – Harvey LJ, McArdle HJ. Biomarkers of copper status: a brief update. Br J Nutr. 2008 Jun;99 Suppl 3:S10-3. – Juan J. Díez, Pedro Iglesias. (2014) Serum cholesterol and triglyceride levels in diabetic patients with subclinical hypothyroidism. Endocrinología y Nutrición (English Edition) 61, 419-425 – N. Silva, O. Santos, F. Morais, I. Gottlieb, M. Hadlich, T. Rothstein, M. Tauil, N. Veras, M. Vaisman, P. d. F. Teixeira. (2014) Subclinical hypothyroidism represents an additional risk factor for coronary artery calcification, especially in subjects with intermediate and high cardiovascular risk scores. European Journal of Endocrinology 171, 327-33 – […]

  5. […] Dr. Cate Shanahan – I’ve referred to this same post a while ago, but I’ll link it again here.  She’s part of Mark Sisson’s Primal Advantage program.  In this post she describes reading about people that have gone low carb and developed elevated rT3, and thinks this is mainly due to going low carb too abruptly.  She says that she’s been able to avoid this problem in her patients by transitioning them to low carb gradually over time. […]

  6. Hi,

    I was doing a cyclic ultra low carb diet that (I think) caused my LDL to go up rapidly. After doing a Thyroid test, it was on the low side. I’ve added back carbs and will retest LDL soon but I really preferred the effect of low carb (leaning out) what do you think is to low? is 50 grams a day too low or would that be gradual enough to prevent LDL issues? All my other numbers are great CRP, LDL is big and fluffy, particle count low, just not clearing from the blood.


  7. Paleo is not lowcarb, that is a misconception. Paleo is carb neutral. It means whatever carb level that suits you. Going grain free doesn´t mean going lowcarb necessarily, it just means getting rid of this type of carbs that can trigger inflammation, leaky gut etc. Some prefer a lowcarb Paleo diet, some say that high or medium carb paleo is the best but it is very individual. There are healthy carbs in many other vegetables.

  8. You may want to read some of Paul Jaminet’s work. I too felt like crap on a very low carb diet but after following Paul’s advice I’m finally regaining my health. Good luck.

  9. Hi Dr Cate, I have been following a Ketogenic Diet without dairy and eating mostly oily fish, eggs, avocado – for protein between 60 – 70 g day. Appropriate for my body weight and energy expenditure. Leafy green carbs. In total net carbs below 20g; and coconut fat. Eating in total between 1,200 to 1,500 cals a day. I am not really overweight but have lost nearly 9lbs which I am happy about – presumably some of that ‘water weight’. By adding MCT oil I finally managed to get into nutritional ketosis after 4 weeks of not getting there and cutting way back on the carbs. I never get above 1.3mM using the blood ketone monitor. I have had several days of feeling really well…but now this is my third day of feeling so awful – dry eyed, low body temp despite it being midsummer, can’t think straight, and no energy, also feeling vaguely nauseous. Constipated (I am drinking adequate water). No hunger pangs at all.
    I am following this diet because I have intolerances to certain foods, chronic fatigue type symptoms when I over do things – with a feeling I’ve got flu when I haven’t; and because I have blood sugar issues, sleep problems and a mood disorder. Blood sugar and mood has remained more stable, and I have been able to fall asleep very easily, whereas before this diet I was not able to at all. However, as I write to you, I am making a little brown rice to eat now to introduce a little carb back and see if this helps address these immediate symptoms, because I realise I cannot go on another day feeling like this. I am in a dilemma regarding all this! Of course, nothing is as clear cut as things seem; but I am very disappointed that various experts in the field of KD are not pointing out the problems that can happen attempting such a diet and way of eating. I am grateful to Dr Peter Attia for at least mentioning he didn’t honestly know why some women, in particular do not seem to do so well on a KD when pre and menopausal. I am post menopausal and although I took bio identical progesterone in the premenopausal stage, I don’t now, and I never suffered hot flushes. And, now, I am sure, for me, who already had a thyroid that I suspected was not functioning optimally is now seriously in distress.
    If I reintroduce some starchy carbs back – less than 100g to start with, no doubt this will take me out of ketosis, certainly as I was struggling to get to ketosis when eating max 20g net carbs. From the way Drs Volek and Phinney describe in their book ‘The Art and Science of Low Carbohydrate Performance’ it seems, to me, they are saying your body either operates by using carbohydrates for fuel OR ketones once the body is no longer ingesting enough carbs, it will then adapt to making and using ketones – which they say usually takes between 1 and 4 weeks…so, I guess I am asking if I am no longer in ketosis, how can my body adapt to a low carb diet? Yet, that is what you are saying, I think. Will this mean I can eventually try to go back to being in nutritional ketosis, or not?
    Please advise – I live in the UK and I have friends who are doctors and they are so sceptical of the whole LC thing anyway, and my own doctor would not support me in this. I feel overwhelmed now by feeling I am weakening my already not too strong body and mind. I do not have the money to spend on a nutritionist – and if I did find one it would have to be one who knows about KD and knows of these potential problems and how to address them.

    1. Not to state the obvious but we wrote 2 books and if you have not read either you will learn a lot about what you might be doing wrong.

  10. Hi Dr. Cate! I learned about you from Sean Croxton’s podcasts and I am a big fan of both of you! I myself am an orthopaedic surgeon and now use natural health principles in treating my own patients – thanks to you! Could I get your advice for my wife please? She’s 45 and had radioactive thyroid ablation when she was 18 for Graves disease. She’s been on levothyroxine since then. We have been gluten free for 2 years, but not dedicated paleo tho’. She tried porcine thyroid last december and she went severely hypothyroid over 2-3 months. Her family doc then put her back on levothyroxine and stopped the porcine. Since then, she remains hypothyroid (no blood work to support this…just symptoms). She just doesn’t feel right. She’s gaining weight, has muscular pains and back spasms, dry scaly scalp, cold intolerance, low energy, etc. Any advice? Thank you so much! Jaydeep

    1. If t3 has not been checked that may be an easy fix. Otherwise, make sure her diet is optimized to exclude bad fats and include all Four Pillars and a consultation with a knowledgeable low-carb doc in your area may be worthwhile.

  11. This article explains exactly what I have been going through. May 2012 I decided to go on a low-carb diet, after having exercised intensely for 8 months without changing from my high-carb-low-fat diet– and without losing weight. Within two months I was so lean that my girlfriend begged me to put on a little weight again. But then, at the same time I started feeling extremely tired especially after 7-8 PM, I would feel as if I was half asleep and exhausted. Interestingly, at first I was feeling good, relaxed and not hungry at all when this occurred. But after another month or two of a strict low-carb diet I started feeling really exhausted, plus I started having problems with constipation and insomnia– and during winter I started to gain weight around the mid-section, as well as losing a bit of muscle.

    I am now much less strict about my carb intake. I usually eat low-carb meals, but I’m not afraid to eat a small serving of potatoes or white rice once in a while if I start feeling fatigued and brain fog. Usually I will get a surge of energy and high spirit within 30 minutes of eating just one small potato at night– this has also helped me sleep much better.

    Anyway, thanks for the article, I guess my switch to a low-carb diet was very abrupt and it seems like I put too much stress on my body during the last year. I am now trying to reverse that with more carbs and better sleep.

  12. Hi, I started low carb in Jan 2013 and have been losing weight (a lot at first and now about five pounds a month). A few months ago I started having these symptoms (of feeling extremely cold and muscle fatigue, losing hair, etc). I started taking magnesium/supplements and made sure I was eating enough fats and calories since I really reduced them – though not on purpose. This seemed to make things better and I would have days with bursts of energy. Now a few months later it is happening again though I have not slacked off in making sure I am eating enough. I recently was reading about certain things (PUFAS, etc) being stored in your fat and as you are losing weight that these may be being released into your system. Have you heard anything like that, I am a relatively new follower of your blog/Facebook, so forgive me if you have addressed something similar already. Do you think it is possible that these work themselves out the longer you remain low carb/Paleo?

  13. Hi! I recently had my cholesterol levels tested, and the doctor said my HDL was too high, at 63. But i read your book, Deep Nutrition, and i was under the impression that was good. But then my triglycerides were 49. is that really low? there are resting levels….

    On another question, do you recommend any holistic doctors in NYC or Chicago?


  14. I live in England and have recently started the Terriann 123 plan. It is a zero carb diet for 10 days and then introduce healthy carbs after. I am hypothyroid and whilst losing weight on this plan am now concerned it could cause me more problems in the long run? I am on 175mg of Levo and feel tired and lethargic all the time even off plan.

  15. I had the opposite effect – after going low carb, my thyroid went into the stratosphere, with T3 and T4 levels being 3 times higher than ‘normal’ and my specialist expecting me to go into a thyroid storm. I did not associate it with the diet, but decided to leave the diet go until my thyroid was under control. Could it have had something to do with the low-carb diet?

  16. I just had the Gastric Sleeve surgery two weeks ago. I am forced into low carb because Imof how little I am eating, and what I am allowed to eat. I am now on puréed foods. I am getting around a little over 30 grams of carbs a day. I cannot do this gradually. I already am being treated for a hypothyroid. I don’t know what to do. My whole body itches. I am supposed to see my doctor, but they don’t seem to have heard of problems in Ketosis. Is there other help besides doing low carb gradually?

    1. There are many potential explanations for your symptoms aside from thyroid, each with their own unique solutions. It’s best to get help from a low-carb professional in your area. I have a collection of links under the “About Dr Cate/Make an appointment” tab, at the bottom of the page

  17. I jumped into the low carb diet because in the past I had been able to lose weight easily on it. However this time there had been heart issues in between having to have two stints , I had been eating lots of carbs and sugars etc and Hashimoto had been diagnosed. After about 3 weeks I noticed a lot of fatigue but more importantly my heart rate slowed to a low of 57 resting and not going up much hight during the day. Could the low carb diet cause such as this? I introduced oatmeal back into my breakfast and had some rice last night with my dinner without noticing any change. How should I proceed I do need to lose about 40 pounds according to my DR.

  18. […] across this fantastic article that pretty much confirms my the conclusions I came to after my recent thyroid tests, only she says […]

  19. I was low carb for a year. less than 50 a day. i felt amazing, AMAZING. however, when i went off the diet, my hormones went insane. my periods have been all over the board, the doctors diagnosed me as perimenopause and I began losing hair on my head, growing hair on my face, insane acne, ( i just turned 30 ) my psoriasis has spread from a 3 cm patch that i have always had, to all over my scalp. my skin is extremely dry, I have horrible pms. anxiety,depression, cold all the time, cramping hands.all after stopping low carb. these symptoms came on within a week of eating normal again.My doctor advises me NOT going low carb again, i have been eating healthy and excercising, no more than 1400 cal a day, and i have slowly gained 40 pounds. what do i do??!! i want to go lc again but doc says no it will make things worse

  20. Hi,

    I am a 37 yr old male weighing about 220lbs.I recently started this diet (low to zero carb).I have been doing this for about 2 weeks now and my ldl level has shot up to 220+.Triglycerides are very low (about 75) and the HDL numbers are low too (36).Total cholestrol is 274.The CRP test that measures that inflammation came out negative (0.8).Still awaiting the results of VAP tests.

    Can just 2weeks of zero (low) cab diet cause this?.I dont have any familial history of cholestrol.I am thinking of now reverting back to my normal (high carb) diet for a month and get my cholestrol tests done again to see if it become normal.I am thoroughly confused.
    Can you provide any recommendations if I should continue with the low carb diet or revert back to my old diet and start again by slowly cutting down on carbs?.Should i wait some more time in this low carb diet and see if it makes a difference or am I going down the wrong path?

  21. I was doing great on my low carb woe for about 10 months. The problems started when I tried to go VLC to break a long plateau. Within 3 days I had a terrible anxiety attack (I’ve never had one before and didn’t even know what was happening). I immediately went back to eating normal low carb and never really felt “right” again. After several weeks I tried again to lower the carbs and all heck broke lose. Anxiety went through the roof and I couldn’t sleep (can’t fall asleep/can’t stay asleep). I increased carbs 3 days ago and still haven’t regained sleep. I had one night where I didn’t sleep at all. The other nights I slept but not long and not well. I’m left mystified. So many say that carbs are completely unnecessary for human survival but if that is true why does reducing them so far make me feel so terrible? I don’t think I transitioned too quickly. I gave up sugar first then I went to about 100 gr/day then lowered further to around <50 gr/day. It's only when I attempted <20 gr/day all these problems started. I have an appointment tomorrow with a low carb friendly naturopath to begin the process of evaluating my thyroid, cortisol and other hormones. This whole mess is truly upsetting.

    1. After following advice from Paul Jaminet to add back some starch to my diet (according to him my symptoms were classic glucose deficiency) I am starting to bounce back. I am sleeping better and feeling less “ill” overall. I have a ways to go to feel optimal again but so far I’m thrilled to be turning this situation around. Time will tell what adding these “safe starches” will do but for now I’m thrilled to be sleeping.

  22. Thank you for the great information. I’ve been yo-yo dieting over the last thirty years. Up to the age of 21 I was a serious athlete and now, am mostly inactive due to work schedule etc. I go to an ND and am treating my adrenal fatigue and am at the beginning stages of insulin resistance. A few years ago, in 2009, I lost fifty pounds going low carb, low calorie on Lindora but hit the wall with the symptoms you describe in this article and the last few years have gained all the weight back and am on T3 supplementation. I’m so confused about the best approach towards nutrition and wondered if you can recommend someone who can help with dietary changes in Orange County Southern California area. I’m currently a few days into a sugar cleanse, incorporating green smoothies, bone broth etc. and I’ve managed to gain a pound. I’m currently approximately 75 pounds overweight. Thanks for any help you can give!

  23. I have been doing low carb for a couple of years. I found my A1C to be 5.9 about 2 yrs ago and I became very strict. It’s down to 5.5 and I’m still striving to lower it. The problem lies in my latest thyroid tests. I feel fine, I workout, I’m 114 lbs at 5’3″. I’m 58 and have been weight training for almost 30 yrs. I walk every evening, and I do Peak 8 cardio 2x a week. My last TSH was 5.08, T-antibodies 7 and <20, Free T4 1.11, Free T3 2.1. I have no fatigue or any glaring hypo symptoms. My AM temps tend to be lowish (97.3-97.7). My question is …would it be safe to take herbs like Ashwaghanda and Guggul and the iodine that Byron Richards prescribes on his site I am not comfortable messing around with hormones.

  24. Please help me understand this paleo/high cholesterol/hypothyroidism delimma. I have eaten Paleo on and off for about a year – recently did the Whole 30 Paleo version. I lost 5.5 pounds, 4 inches off my waist, with a total of 9 inches overall. At the end of it, just so happened it was time for some blood work to be drawn for wellness insurance benefits plan and my cholesterol skyrocketed and now I have been diagnosed with hypothyroidsim. CHOL 135 to 412; TRIG 59 to 221; LDL 86 to 292; HDL 50 to 76 / and they said my Thyroid testing was over 100, norm should be .45 – 6.675. I am freaking out. I thought this was a healthy plan for me. I have felt really good. Felt stronger than ever. Started Crossfit over 10 weeks ago and felt like I was stronger than I had been in a long time. I am a 49 year old female. So confused now as to what I should do. I do not want to take medications if I do not have to.

    1. Karen if these labs were not done fasting the lipid numbers are not meaningful. If they were, you may be doing a little too much fruit or carb or have the wrong oils. Best bet is to find a nutrition-literate practitioner. For a listing check these sites: and and or schedule a consult with myself

  25. Hi Dr Cate

    As with most topics in health the arguments go back and forth regarding the subject of lo carb diet and thyroid. I find that with my patients T3 reduces and T4 increases due to the inhibition of T4 to T3 conversion. That finding, in part, supports the current data.
    However, not all patients respond the same to that decrease in T3 and that, of course, reflects the complex relationships of the body and the biological individuality of the patients.
    Interestingly, alcoholics have a faster conversion of T4 to T3 and therefore the Lo carb shift to T4 may be an unexpected treatment for them (or hindrance). Although, it is still too early to tell.

    Good luck with your patients.

    Dr Downing
    Director of Clinical Education & Research European Council of Diplomat Doctors

  26. I went through this phase. It is called the “Keto Flu”. It is entirely normal and passes in a week or two if you are managing your macronutrient ratio and electrolytes effectively.

    1. I don’t think that can be the case – after all, then the low carb wouldn’t make sense, because you’d be burning less because you’d be sedentary.

  27. Hi.

    I was wondering if this kind of a diet/ exercise plan will work for fat loss without muscle loss when I am a 78kg, 184cm male in my early 20’s:

    Monday: HIIT (20 min) – 2200 kcal
    Tuesday: Heavy upperb. – 2450 kcal
    Wednesday: Free – 2200 kcal
    Thursday: Heavy lowerb. – 2450 kcal
    Friday: Free – 2200 kcal
    Saturday: Mixed calisthetics – 2350 kcal
    Sunday: 45 min steady cardio – 2350 kcal


    2200 kcal = 200g prot, 120 g fat, 85 g carbs (veggies)
    2350 kcal = 215g prot, 130 g fat, 85 g carbs (veggies)
    2450 kcal = 240g prot, 105 g fat, 135 g carb (veggies and fruit)

    and a re-feed of 3000 kcal every 14 days with the heavy lifting on thursday looking like this:

    240g prot, 138g fat, 200g carb

    Thanks a bunch.

    p.s. I also take 600mg phospatidyl serine, 400 mg EGCg, multivitamin x2, 5000 IU d-vitamin and will start taking 10g l-leucine on workout days (5g on non workout days).

  28. just found you and this thread… exactly what happens to me!!! i purchased and read your food rules, hoping it would answer this question but it didn’t. just wondering how high my carbs should be to start and how quickly i can lower them.

  29. wow- excellent.. that article explains this issue so well….

    If only i wasnt diabetic so I could try carb cycling and also perhaps adding back more carbs to then reduce them gradually – but the irony is that I wouldnt have ever been interested in low carbing unless I became a diabetic in the 1st place ! lol

    some days I have an extra meal meaning I get to 40 or 45 grams carbo per day. but not often….. when i initially went low carb back in April 2010 I adjusted very easily – but my LDL cholesterol went from 80 to 285!!!! – now finally with T3 its reduced back down to 159 and prob still on its way down further..

    Needing to take thyriod meds (t3) for the rest of my life is worth it to be able to stay on low carbing to get good blood sugars right?… (I have diagnosed Hashimotos and type 1 diabetes)….

    I think this topic needs to be really put out there as much as possible so people going low carb may be able to avoid these problems or be prepared for them…. If I had of known this 2 years ago then it would have saved me many headaches wondering why my LDL suddenly ski rocketed.

  30. Great Post Dr Cate…….loved it, i went from sugar burner to fat burner overnight and only had about a week of feeling like shit…now a pure fat burner with no side effects luckily 🙂

  31. Hi Dr Cate,
    Your post makes complete sense to the way I’m feeling, but I wondered if you could fit some more symptoms into your hibernation theory. I think they fit but I’m not sure how. I’m 40 now, not overweight, but have had very low energy levels and hair loss for a few years. Insulin resistance was mentioned, but nothing further was said or done. My thyroid levels were nearly normal, but I was prescribe synthroid. This made me worse. I was prescribed Armour instead and this made me worse too. I’ve been gluten and dairy free for ten years and processed food and sugar free for 5. I gave up all grains about a year ago and ate lots of fresh organic produce, sprouted food, meat on the bone and broths, but no fermented food. Three months ago I started a very low carb candida diet. But just before I started it I had been prescribed a low dose of T3. This also made me feel terrible, with no energy and a longing to hibernate I felt like a leaden zombie. So that was stopped. I’m still on the VLC diet, but still feel awful. I’ve tried dessicated adrenal (containing small amounts of adrenal hormones) and cortisol on it’s own. These have the same debilitating effect. And so does Vitamin D (a summertime sunshine vitamin) and even coconut oil (a fat metaboliser). Since starting the VLC diet I have got fatter and flabbier, but my hair loss has slowed right down. Also I feel at my worst just after eating and it doesn’t matter what I eat but a bit brighter if I don’t eat for a really long time. However when I do that I feel even worse the next day.
    Can you explain why thyroid hormones, cortisol, vitamin D, and coconut oil (and eating!)make my symptoms worse, and why I’ve got fatter on the VLC diet, using the hibernation theory?
    I’m scared to eat carbs again and don’t know which ones to try first.. The candida diet recommends beans/pulses. What do you suggest?

  32. I am a 6 yr survivor of Thyroid cancer. I had to have my thyroid totally removed. I take 150 mcg Synthroid daily. Been on the Paleo diet for 5 days now…..have no energy at all, getting cranky and moody. I feel like I do when I have to come off my Synthroid for 6 wks to have a cancer scan done….HORRIBLE, a real Nightmare.

    Is this diet going to work for me?? Should I even be trying this type of diet, not having a thyroid?? I am truly at my wits end…..I am approx 100 pds over weight and have not had real energy in years.

    Can anyone shed any light on this for me??

  33. Hi Dr. Cate, great post. I started eating lower carb in late February of this year and then in March cut out all grains/most starches. I’ve lost 35 pounds so far and hope to lose another 40 – 50. In June I noticed my hair was thinning but thought it was my imagination until my husband exclaimed, “you really are thinning” one day. Ugh … I have had some dry patches of skin on my face but no where else and I don’t think I’m fatigued (I have two small kids so hard to say … lol). I did a search a few weeks ago and read what Dr. Eades says about telogen effluvium and assumed that maybe it. How can I tell if it’s that or a thyroid problem? I feel so much better eating this way but this situation is a little distressing. Thank you!

  34. This is exactly what happened to me. After being on Atkins for 4 months I lost 47 pounds and felt great at first. Then the fatigue started, the dry skin, and worse of all my hair is falling out like crazy. My thyroid tested normal. Please, are you saying that by adding back carbs (say maybe fruits) I can stop these symptoms? I really don’t want to go back to eating bread and sugar.

    1. Possibly. Atkins is not necessarily a balanced diet (several of the Four Pillars are missing) and until you identify and add back what you are missing it may be easier for your metabolism to get a break from ketosis for one to two days per week using fruits, sprouted grains, beans–whatever suits you best.

  35. Hi,
    First, I want to thank you for your book, Deep Nutrition. I found that it explains very logically some mechanisms in the body that “regular” doctors simply dismiss as explainable.
    I say this due to the experiences of my parents which have several health issues but got virtually no useful advices beside lots of pills and a recommendation for bypass.
    I finally convinced my mother to start using Kefir and she was ecstatic to have her fasting glicemia drop from 237 to 125 in few days.
    I for one had as a teenager aches in my joints following a streptococcal infection. That lasted for over a decade when I quit eating meat. Even now, my joints are completely free of aches, except low back pains due of a spina bifida occulta. Now, at 40, my joints are a bit stiff and I annually „clean” those using bay leaves infusion.
    While I was vegan, I had little interest in eating healthy, so after sever years I discovered a severe anemia. It got better with medication. So I went back on meat, liver, but anemia kept coming back.
    After having my second child, I gained a lot of weight I could not loose for vanity purposes.
    For about a year, I decided to get back my health. I hate taking medication and it seemed with my family history and borderline obese I wasn’t to far away from it.
    I found the nourishedkitchen blog which opened up a window to new possibilities, introduced me to bone broths, sprouted and fermented foods, W.A. Price studies, your book and lots of interesting stuff.
    So I cleansed my urinary system with lots of cinnamon and of stones with the parsley tea recommended by Dr. J Howenstine.
    I had a gallbladder cleanse with Epsom salts, olive oil and lemon juice, which got me clean of the bitter taste in my mouth and the dull pan in my liver. Plus I have sub-lingual bleeds every 6 months (ancient custom here, in Romania).
    My digestion improved a lot with Kombucha over only two months. I also started to take Kefir which is clearly great to put on my skin instead of night cream.
    So I make efforts to clean up essential systems that are meat to maintain health, systems that after years of imbalanced lifestyle are overwhelmed and in need of assistance.
    I also take fish oil, alpha lipoic acid, and chromium, mostly for pancreas.
    After only a few days on Montignac, I went to Atkins, about a month ago. The rapid weight loss was, of course a lot of water, which made me very dizzy, but went away as I learned to drink water with lemon and have a pinch of salt afterwards.
    But after about a week on Atkins I had a horrible day, I felt like I was as dry as a desert inside, I felt like a something was crushing me from inside, despite drinking plenty water. So I went to my kitchen and had a huge glass of celery and cucumber juice (now wanting to make something out of sweet fruits).
    Therefore, I decided I need to eat more raw vegetables and fruits than only two tomatoes and a dozen of olives.
    And since is the time of year for strawberries and raspberries I eat them, more that what is “right” for a low carb diet. Most of them I let them ferment overnight in Kombucha (thanks to your passage about monkeys and the way they digest fruits). I hope that will lower the sugar content, while keeping the enzymes alive. I love the taste.
    I found out that adding grains (as in homemade noodles) is not the best thing for me, as I feel the post-eating fatigue if I ear more than a few bites.
    I also saw some information about alkaline diet, which makes sense to me.
    Thing is in low carb, ketogenic diets is easy to eat lots of proteins like lean meat that will have a certain impact over the body, acidifying it. I think that it also makes sense to eat according to seasons, eating most what is really fresh in the local market. I doubt cavemen hunted and eat a mammoth every week all over the year.
    And food is more than nutrients, the more energy of life which translates in physics as enzymes and so on, the more energy you get in.
    When starting to loose weight and gain health there are massive doses of toxins released from deep within our tissues, which may make us feel worse before we get better.
    Thank you.

  36. I have been on the Paleo Diet for about a month. I am thin for my height, not on this diet to loose weight. My husband read something that indicated it could resolve stomach acid problems so I decided to give it a try. Also, I have Grave’s Disease (hyperthyroid). I have read in a few places online now, including this site, about the issues with people who have hypothyroid, but not hyperthyroid. I have been on medication for this for over a year, and the only time I have had a recurrence of symptoms was when getting off the medication for a week, and now with this diet. Since being on the Paleo Diet my symptoms are unbearable: extreme anxiety, shakiness, no energy, can’t sleep, feel like I’m going to pass out all the time, cry all the time. I suspect it’s this diet and something similar to what you discuss on this site for those with hypothyroid. Have you run into anyone else who has hyperthyroid with these symptoms when on Paleo Diet? I went cold turkey, by the way. One day eating carbs, next day not.

      1. I had some symptoms immediately, but the websites all said the shakiness and light headed feelings were normal and to give it a few weeks, so I did. The anxiety and sleep issues hit around 2 1/2 weeks and are getting progressively worse.

        1. I’m assuming someone is checking your glucose levels and your only endocrine (hormone) issue is hyperthyroidism. You may have had some insulin resistance even with normal weight and one less-than-ideal but easy way to tell is if your glucose is over 90 in the morning after an 8-12 hour (and no longer) period of fasting. If this is the case you simply need to proceed more gradually with the diet changes. Even if you do not have insulin resistant gradual change is prudent. The changes you made in adapting paleo likely involve not only cutting carbs but also increasing protein. These beneficial changes demand upregulation of many genes that your previous diet may have downregulated and this makes gradual changes a necessity. (If this information has been helpful, please SHARE this post everywhere! 🙂

  37. Thank you for this article. After 8 months of very low carb dieting I hit a plateau, and had a bunch of symptoms: cold hands, constipation, dark circles under my eyes. All hypothyroid symptoms.

    Having lost over 100lb in a year I am terrified of eating carbs again, but I’ve had to do so. I’d still like to lose another 20lb, but it’s not happening. Frustrated, and worried about my poor thyroid!

    1. Great work on the 100 lbs! That is fantastic. There are so many reasons you may be hitting a wall here and permanent carb increase is not necessary the solution. I think you may neet to get some help from a good low carb doctor. Check out the American Society of Bariatric Physicians website, or Jimmy Moore’s website.

  38. I have shifted from high protein via meat, no milk/eggs, relatively low carbs (no wheat, corn, potatoes, minimal sugar) to your approach – adding in raw whole pastured milk products (yogurt, cream, milk, kefir, cheese, eggs). I did not need to lose weight but needed to reduce inflammation (asthma, osteoarthritis). Since starting, have lost 7 lbs- from 125 to 118 (I’m 5’6″) in about 6 wks. Should I be concerned? Should I change something? Should we talk?

    1. Good for you for making healthy additions. I hope you are also feeling better. If not, feel free to contact me about a consultation (click on tab: make an apt).

  39. Oh, and I realize I should eat protein as well as fat with all meals but the point I wad making was that before I could eat 50g sugar + carbs in a sitting, and yes I’d feel.the crash afterwards.and would sometimes feel hypoglycemic, but two weeks later and I have a much worse reaction to 1 cup of veggies – There’s got to be worsening insulin resistance happening by cutting so fast.

    1. Rachel, I will be doing a post soon about this common issue that is very often misunderstood. Stay tuned by subscribing and please pass the word around if it’s useful to you because this is the NUMBER ONE problem with folks going low carb on their own, that is, without medical guidance. Meanwhile, I recommend you call around to find a low-carb or Paleo doctor in your area.

  40. I’m wondering if I should keep on truckin’ through the hard times until my body adapts or if I should slowly incorporate a few more carbs per day? I feel like just reverting to my old diet would be too drastic for me again, seeing as how a cup of steamed greens caused such a huge dip in my blood sugar.

    Any advice would be cherished.

  41. And by low carb I mean from cakes, toast, pastas to one piece of toast and/or bowl of oatmeal with almond milk a day. Drastic. It’s only been a week and I feel so much more insulin resistant now than before and have been searching for WHY because I’m now eating no carbs other than veggies.

    I’ve had 3 episodes of hypoglycemia ~60 blood glucose level with symptoms in one week. I cant eat a bowl of veggies with avocado without getting hypoglycemic.

  42. I’m 24 and thin but for 3 years I’ve had anxiety, adrenaline rushes at night preventing sleep, feeling hungry all the time. I was told it was in my head and given anxiety meds. Truth be told, I never took the meds. I wasn’t convinced. I’ve been cutting so many different “allergens” from my diet attempting to find a “culprit” and after being diagnosed with PCOS recently, I realized my long list of symptoms sounded like insulin resistance!

    So without medical guidance I went low carb.

  43. Susan,

    Oh, I can really feel the frustration, and I understand it. For a lot of us, the books—even when we’ve taken the time to carefully read and study a number of them, as you have—can only take us so far. I’m so glad you commented, because I promise you there are a great number of others who have hit the same kinds of roadblocks.

    It for people like you that I decided to set up a one-on-one consultation service. Often, people have, all by themselves, managed to get just about everything in place, but cannot get those last pieces of the puzzle in place. That’s why I recommend that, if at all possible, you engage in a one-on-one consultation with a health care professional familiar with the fundamental concepts laid out in Deep Nutrition.

    If you think you might like to set up an on-line consultation, click here to learn more.

  44. sorry , i meant should i go for a high carb diet flush out RT3 and then slowly start on low carb ? not sure what to do..Been trying lots of diets and exercise but not able to loose weight.even if i loose it comes back again.Very low carb i feel nervous and not able to function.but what i have seen is if i keep my excercise constant i loose weight.But i dont have energy most of the days to workout and skip workouts.Please suggest what should be my next step.Thanks a lot

  45. so low dosage, plus low carb crashed me.i knew low carb is the way to go , but was not sure why i crashed.Now everything makes sense to me.and always i have had pretty high insulin levels and hypoglycemia.and its a vicious circle.Not sure how to break it.I did my blood work.TSH- 2.12 , Free T4 1.61 (0.82-1.77) , Free T3 3.0 ( 2.0 -4.4 ) , RT3 43.2 ( 13.5- 34.2)
    Is my RT3 in a very bad shape.Do you think if i should go on a low carb diet with this RT3.So should i go for a high carb diet

  46. Hi Dr Kate ,

    I am have hypothyroid for the past 12 years and i have been on Levoxyl.i am nealry 100 pounds overweight.I tried Tim ferris diet ( low carb ) for 20 days.I felt great in the beginning , but crashed at the end of 20 days.I was bed ridden for almost a month with low BP , dizziness and severe hair fall.My bad timing , i started birth control pills 2 months before starting the diet and was feeling hyper.So my gynec by mistake asked me to reduce the thyroid tablets.

  47. Hi, Dr. Cate!

    I read your post and now wonder if I, indeed, DID cause my pituitary or thyroid to tank. After being a vegetarian/vegan for all my adult life, I ate Paleo/Primal after the birth of my child and lost all my baby weight. I was later put on thyroid meds and sex hormones and have gained all the weight back and THEN some. Still gaining. I eat moderate carb and wonder if I have to increase the carbs more or wait till I get the meds correct. Is it even possible to lose when hypo?

    1. Whey hypothyroid is treated you can lose weight. Many women develop thyroid problems after delivery and it’s unclear why, but of course I suspect a pro-inflammatory diet has something to do with it. As far as what you should do now, I think you may benefit from working with a low-carb doctor in your area. (Or you could book an online consultation w/ me!)

      1. Thank you, Dr. Cate! I really could use a consult with you and will save to do so (as I’m getting nowhere with the professionals I deal with now). Thanks again for your reply.

  48. searched ‘sleep problems’ and this is the closest that came up, I am having problems waking up in the night hungry. What’s odd is that I felt full and slightly bloated after dinner (sashimi and beef w veg) but now I’m hungry. I’ve tried adding in extra fat (butter and lard) but it doesn’t seem to be helping. Thanks for any suggestions, I’m 37, lean and active and with no obvious health problems that might be the cause.

    1. There are numerous potenial causes underlying sleep disorders so giving you advice without a complete history could certainly send you down the wrong path as well as miss something important.

      1. ok, thanks for the reply. I live in Japan (Okinawa, of all places!) so open-minded healthcare can be hard to find – I once went to a doctor and all I got was sleeping pills 🙁 I’ll consider a consultation with you but in the meantime are there any books you can recommend that might help? Lastly, still couldn’t sleep last night after eating low carb, so I got up again and had a banana, and was then able to sleep. Could carbs/blood sugar be the issue? Thanks again.

        1. I’ll add that I don’t think it is stress. I’ve done a lot of this: (I cannot recommend this highly enough!!) and am now feeling happier, more in control, and more able to enjoy life than I have in years. It does feel like diet is the issue. Thanks again.

        2. Quite possibly but there are numerous other explanations that a history might uncover if you get to a good doctor!

          1. ok, thanks again for the replies (I’m sure you are very busy)! If adding in a few more carbs doesn’t solve the issue then I’ll look into the issue further, maybe get some bloodwork done (maybe even consider a phone consultation with you). Thanks also for your books, I’m looking foward to the TRIM book when it comes out.

  49. Without knowing background information that is not appropriate to discuss in the context of a blog I can tell you that I have yet to see a patient with abnormal thyroid function tell me they feel good! But–one can have normal function with abnormal growth processes so the ultrasound is important.

  50. Hi Dr. cate!
    Ironically, I went for an ultra sound today of my thyroid. I do not have results but my doctor wanted to be safe since she felt the swelling of my thyroid. I recently switched drastically from high carb to low-carb high fat. I’ve been successful and have not felt any symptoms from hypo/hyperthyroidism. I exercise 3-4 days a week for about 1 hour. Running or weight lifting and usually eat 3 meals a day.Should I incorporate a little more carb intake? Or will this go away? I feel great

  51. Hi Dr. Cate. Would you suspect something similar with hibernation mode for long term low carbers too? I’ve been low carbing for many years and have lost 175 lbs, but have hit a long plateau of over 4 months now with 30 lbs still to lose. My TSH has been in range with levoxyl (checked regularly the entire way), perhaps I should get my reverse T3 checked? I don’t have any symptoms of fatigue, etc. and my daily carbs is around 40 or so (30 net carbs) of good veggies, lots of fat calories, etc

    1. Unlikely to be a thyroid issue without the expected symptoms. You’ve lost an amazing amount of weight, very impressive, and with only 30 to go for a normal BMI then it’s probably just an issue of your body needing to be “sure” you want it to keep going. There’s a lot going on at the cellular level that requires consistent ‘messaging’ in the form of nutrients, sleep, exercise. Keep up the good work!

      1. Thanks! I may ask my endo to do the reverse T3 test the next time just to see. But overall, I feel pretty good and love the way I eat. I’m use to plateaus but this is the longest yet so I’m looking for ideas that might help me get past this one. I’ve tried adjusting nutrients (upped the fat and calories, eliminated stallers like dairy and yeast foods) and may trying upping the carbs next to see if that helps. Sleep and exercise are solid too. Started on bone broth this week too. Thx!

  52. Also, one more thing. What do you guys thing on this food combining idea? That one should not mix protein with carbs because the digestive juices cancel or whatever. I been doing that but I really don’t find much support for it and it does not make sense. For, example, Weston Price showed how primitive people eat their protein combined with carbs, almost al the time. And they were pretty healthy.

  53. I was on a low carb diet for a about a year (<100 g) but I could not gain too much muscle with it. I am a fairly slender guy, and upon adding high glycemic carbs and protein after a workout (raw skim milk with banana, some grass-fed whey protein, a tbsp maple syrup, no fat) adding muscle has been easier and I feel more energetic. I eat about 50 grams of carbs post workout to induce an insulin response. I still eat high fat the rest of the day, just not around my workout. Any thoughts?

    1. It’s an interesting idea, however in reality I’m sure how much insulin your body needs to ‘sop up’ those 50gm of carbs after a workout b/c hungry muscles will do this in the absence of insulin. You’ll probably get a better response by doing workouts in the AM, eating a big meal, then taking a nap.

      1. I do workout in the mornings and always eat after that. Before I used to have a smoothie with raw whole milk (or coconut milk) and 2 or 3 eggs and it was sort of hard for me to gain muscle. But now I can see that I am gaining more lean mass after getting the carb/protein combo and also have more energy. I guess it’s still okay since I eat less than 100 carbs a day. What do you think? By the way I love your book Deep Nutrition; it got me into bone broths! Thanks Dr. Cate!

        1. Carlos, perhaps you might find interesting the Cyclical Ketogenic Diet. It is designed for body builders. Consist of alternating low carb, for let’s say 2 weeks and a few days of high carb, to replenish live and muscle glycogen and gain mass. I saw it in Lyle McDonald’s book Ketogenic Died. Also there lots of information for sport oriented peoples. If could send it by email if interested.

  54. Thanks for guiding me here Dr. Cate,
    I get it, so adapting to low carb is key to maintaining t3. I also wonder what you think is true for athletes who expend more energy, if they may require more grams of carbs, with increased overall expenditure?
    Also, do you think that taking t4 supplementation may result in more thyronamines if rt3 mechanisms are in place?
    Also looking forward to a phone consult, as I was coming to see you last week, but the drive is simply to far.

    1. Athletes do require more energy, but I do not think it would matter whether it comes from fat or glucose. Those athletes who are able to store more muscle glycogen would tolerate a higher glucose intake. And yes, to your question about t4 supplementation.

  55. Thank you for the article! I went Paleo very abruptly and have had the hibernation fatigue and hair loss, and also a slew of severe PMS-like symptoms like irritability and depression. I hope the gradual approach will help.

  56. Cool post Dr. Cate, maybe if you have a chance to work with someone that has had this happen to them and your able to coach them through it you could post about how you were able to help them. I know you can’t really give medical advice but to know it’s possible to transition over slower would be encouraging. I’m not really willing to go back to low carb because of the anxiety and everything else along with it, even after working with a practitioner that says “it works for everyone”.

  57. Another trap you can fall into. You cut wheat and sugar, but you don’t have a lot of meat and cheese. Your body gets into a very alkaline state. You feel miserable. You wonder why your heartrate spikes when you take a vitamin c pill or 1/4 tsp of rice syrup. You eat more acidic foods like meat, cheese, and black tea and you feel like king of the world. And by you I mean me. No one talks about this except a local dr I know.

  58. This is fascinating. Ive spent 2 years looking for info on “when paleo goes wrong.” I started paleo 2 yrs ago. Felt awesome. 3 weeks in, massive gallbladder attack. Fought my Gb, and these thyroid symptoms, for 18 months. Finally had the Gb out when I couldn’t tolerate the pain anymore. Now I’m working with a traditional foods nutritionist to get back in the game and resolve my prediabetes. Im resolving to not do Lazy Paleo, relying only on meat and nuts! Dark green veggies with every meal…

  59. I’m still on my quest to deal with Very Challenging Symptoms…and am mostly coming up with more questions than answers! But it’s fascinating! And I just listened to a podcast interview with Chris Kresser last night, and took some detailed notes because I thought others might appreciate his thoughts on thyroid and hormonal health: . His approach complements yours, Dr. Cate–thanks for continuing the discussion.


  60. Awesome article Dr. Cate!

    I was excited to learn I am not the only one interested in the effects of hibernation. I’ve long thought it was so fascinating. Bears go to sleep in early Winter, wake up several months later with almost no muscle loss, tons of fat loss, little movement during the winter, they stay normal thermic, yet their HR plummets and they don’t even really drink water. Amazing.

    Mike T Nelson PhD(c)

  61. You are so right, Margarete. I sought the aid of a doc for hypertension. He gave me a prescription which lowered it to 140/80. I was not happy with this but was told it was okay at my age. Saw an endocrinologist to get hormones checked, told him about zero libido in addition to other stuff. He told me it was normal at my age. It’s wrong to tell people in their 60s they are old. I have contacted Chris Kresser & plan to see Dr. Cate (calling later today)

    Both are about 45 min from me!!!

  62. My doctor will tell me to take Prevacid or some other medication, I don’t trust medication…I do, however take my thyroid med daily. I refuse to take statins, too, they make me feel like crap. therefore I am trying to live a healthy life instead and eat well.
    so, that’s why I think people will try to make these changes on their own, fearful that a doctor will either ridicule them or just prescribe some other medication or both!

  63. Good advice. : ) One more question: if a woman had Hashimoto’s thyroiditis, is it caused by being low carb or would being low carb along with thyroid meds actually help that condition?

  64. Thank you. Dr. Kresser is the reason I first tested my blood sugar and found it high. I’ll contact him.