Intermittent Fasting as a Therapy for Hypothyroidism

Reader Adam Kadela has begun intermittent fasting and wonders how it might affect his hypothyroidism:

I have a question pertaining to the section at the end of the book covering extended fasts. I regularly practice the 16-8 fast/feast protocol (breakfast at noon, last meal before eight), and plan to throw in a 36 hour fast once a month per your book. However, I am hypothyroid (hashimoto’s) and take synthetic T4 and T3 (unithroid and cytomel), so I’m wondering if an extended fast could affect my thyroid function negatively.

This is a great question. I think the daily 16-hour fast should be therapeutic for hypothyroidism, but I’m not sure about the 36-hour fast.

In today’s post I want to talk about why daily intermittent fasting may be therapeutic for Hashimoto’s, which is an autoimmune hypothyroidism.

Food Sets The Circadian Clock

The circadian clock is strongly influenced by diet: indeed, food intake dominates light in setting the circadian clock. If you regularly eat at night and fast during the day, the body will start treating night as day and day as night. [1]

(Alcohol consumption at night will also tend to reset the clock, which may explain why college students are often night owls!)

This suggests that controlling the timing of food consumption can help to maintain circadian rhythms.

The Circadian Clock and Hypothyroidism

The thyroid follows circadian rhythms. There is a circadian pattern to TSH levels:  high at night, low during the day.

The thyroid’s circadian pattern is diminished in autoimmune hypothyroidism. In a study of hypothyroid children, the night-time surge of TSH averaged 22%, compared to 124% in normal children. Only one of 13 hypothyroid children had a night-time TSH surge in the normal range. [2]

The study authors concluded:

We suggest that the nocturnal surge of TSH is important for maintenance of thyroid function and conclude that the nocturnal TSH surge is a much more sensitive test than the TSH response to TRH for the diagnosis of central hypothyroidism. [2]

Shift Work and Hypothyroidism

If circadian rhythms are important for thyroid function, we would expect shift workers to have high rates of hypothyroidism. Shift workers sleep during the day and eat at night, which disrupts circadian rhythms.

It turns out that shift work doubles the risk of autoimmune hypothyroidism:

Stress induces autoimmune disorders by affecting the immune response modulation. Recent studies have shown that shift work stress may enhance the onset of the autoimmune Graves hyperthyroidism. On the other hand, the possible association between occupational stress and autoimmune hypothyroidism has not yet been investigated…. Subclinical autoimmune hypothyroidism was diagnosed in 7.7 percent shift workers and in 3.8 percent day-time workers with a statistically significant difference: Odds Ratio (OR) 2.12, 95 percent Confidence Interval (CI) 1.05 to 4.29; p=0.03…. Our data show a significant association between shift work and autoimmune hypothyroidism. This finding may have implications in the health surveillance programs. [3]

Shift Work Affected Adam Too

In a follow up email, Adam told me that night shift work may have helped cause his hypothyroidism:

[T]he paper about thyroid and fasting … is particularly interesting to me due to my experience with night shift work for 10 months last year. My circadian rhythm was all out of whack due to experimenting with different sleep schedules and trying to workout around midnight before going into work at two a.m. I also played around with different diet strategies (grazing method w/ small meals, warrior diet, and ultimately settling on the 16-8, which is by far superior imo). My thyroid, along with other hormones, did not enjoy these trials.

Intermittent Fasting May Be Therapeutic

Since the circadian rhythm is affected by both food and light exposure, lifestyle practices can enhance natural circadian rhythms. These practices should optimize the circadian cycle:

  • Light entrainment:  Get daytime sun exposure, and sleep in a totally darkened room.
  • Daytime feeding: Eat during daylight hours, so that food rhythms and light rhythms are in synch.
  • Intermittent fasting: Concentrate food intake during an 8-hour window during daylight hours, preferably the afternoon. A 16-hour fast leading to lower blood sugar and insulin levels, and the more intense hormonal response to food that results from concentration of daily calories into a short 8-hour time window, will accentuate the diurnal rhythm.
  • Adequate carb intake:  Eat at least 400 “safe starch” carbohydrate calories daily during the afternoon feeding window. Relative to a very low-carb diet, this will increase daytime insulin release and, by increasing insulin sensitivity, may reduce fasting insulin levels. It will thus enhance diurnal insulin rhythm.

Adam tells me that intermittent fasting seems to be improving his hypothyroidism:

I think you’re correct in that I’ve experienced some curative effects. However, with the improved nutrient absorption and gut health from healthier eating and fasting, I think I fluctuate a lot b/w slightly hypo, normal, and hyper, since my medication is constant. I’m still in the process of finding a balance, but it’s a bigger improvement than my past state.


Many doctors mistakenly assume that little can be done to cure autoimmune disorders. In fact, however, autoimmune conditions commonly disappear once the chronic infections, food toxins, or poor health practices that cause them are eliminated.

Circadian rhythms have powerful influences on many biological processes, and disrupted circadian rhythms are a common feature of disease. Without clinical trials it’s impossible to be sure, but efforts to enhance circadian rhythms may be therapeutic for diseases such as hypothyroidism.

Intermittent fasting, daytime light exposure, excluding light from the bedroom, night fasting and daytime feeding are simple practices. But they may be underappreciated keys to good health.


[1] Fuller PM et al. Differential rescue of light- and food-entrainable circadian rhythms. Science. 2008 May 23;320(5879):1074-7.

[2] Rose SR et al. Hypothyroidism and deficiency of the nocturnal thyrotropin surge in children with hypothalamic-pituitary disorders. J Clin Endocrinol Metab. 1990 Jun;70(6):1750-5.

[3] Magrini A et al. Shift work and autoimmune thyroid disorders. Int J Immunopathol Pharmacol. 2006 Oct-Dec;19(4 Suppl):31-6.

Leave a comment ?


  1. Hi Mark,

    Particularly on your sleep schedule, it may be best to make breakfast the largest meal and skip dinner. Eat all food between 7 am and 2-3 pm.

    The advantages of this are (1) all food is eaten in daylight hours, which enhances circadian rhythms, and (2) you go to sleep lightly fasted which should improve sleep quality and immune function.

    The world’s oldest man, Walter Breuning, ate on that schedule – no dinner, finish eating by 2 pm.

    Best, Paul

  2. The Listless Lawyer » Closing Tabs - pingback on June 18, 2011 at 6:42 am
  3. Hi Paul:

    I found this website that takes the opposite view of iodine supplementation, which I find now very confusing.

    As I also have Hashimoto’s hypothyroidism, nicely controlled with Armour thyroid, I have held off on too much iodine supplementation. I get a total of 250 mcg from a multivitamin and a “thyroid essentials” type supplement. I was also iodine deficient before presenting with hyperthyroid and then hypothyroid symptoms.

    I’m frankly afraid to take much more iodine.

    Still, I have poorly controlled Epstein Barr virus, which keeps reactivating. My latest blood work shows:




    My neutophils are also consistently low, with other out of range blood work like High MONOS at 15.

    I wonder if taking iodine might help me to finally overcome this virus.

    The Perfect Health Diet is my last stop, as I've told you before. Starting with a Paleo diet Christmas day 2010, I found the Perfect Health Diet about three months ago, and fine tuned the Paleo a bit more.

    I would appreciate any comments on iodine supplementation safety for Hashimoto's people AND any insight anyone might have on Epstein Barr Virus recovery.

    Like chicken pox, I understand that once one acquires the virus, one always has it, but the immune system keeps it under wraps, so to speak. I have been losing this battle for years. I do think EBV may be what is keeping me from fully recovering.

    I take a great deal of sodium ascorbate for EBV also up to 14 grams a day, depending on how I feel. My Lyme disease doctor encouraged that while I was being treated for Lyme. He also said that Lysine helps to suppress EBV. He had me on Valtrex for the EPV, which seemed to help. I'm going to talk to my family doctor about starting that treatment again, as my Lyme/bartonella treatment is over.

    Your discussion on telomeres and EBV was interesting. EBVs connection with depression and cancer is not encouraging. I'd really like to put this virus in its place.

    Thanks for all of the comments and continued beneficial work for all of us seeking health.

  4. Hi Mary,

    EBV is also associated with MS. I will have to work up some EBV posts. The issues you raise are too complex to deal with in comments.

    I would recommend iodine for Hashimoto’s. Dr K is a top thyroid doctor and I respect his work, but I would place him on the iodine-skeptic side of the spectrum of reasonable views. The negative experiences are usually explainable by selenium deficiency, too-rapid increase of iodine, or some other remediable problem. Many people have had positive experiences from iodine. I think it’s possible to get the positives without the negatives with some care.

    Just be very cautious with iodine. Get all of our other supplements in place first, stabilize, start very low in iodine, change dose only once a month with no more than a doubling of dose. I think getting to 3 mg/day, which might take you 6 months, is where the major challenges for the thyroid come.

    Best, Paul

  5. Hi,
    I also have hashimoto. The GAPS folks say that safe starches are too hard to digest and can aggravate overgrowths of bacteria and therefore recommend fruit. You say, fructose is toxic and you recommend starch. On the other hand, a zero-carb diet leads to glucose deficiency and hypothyroidism. I’m a little bit confused. What to do now?


  6. Hi JP,

    Do you have some sort of gut dysbiosis that requires you to exclude some type of plant food, such as starches? In that case you’ll need to restrict certain foods and work to remediate your gut flora.

    On the other hand, if your gut flora is supportive of all types of foods, you’ll be able to eat both starch and fruit without difficulty. In that case I think starch is preferable, as glucose is a more useful macronutrient than fructose.

    Best, Paul

  7. Hi Paul,

    I have a general hypothetical question regarding your views on chronic disease:

    Do you think that, in some cases of chronic infection, it is possible for the immune system to defeat the infection without the aid of antimicrobial medications once immunity has been fully optimized through diet, micronutrition, and lifestyle improvements?

    My personal health problems have always been relatively mild (in comparison with serious diseases such as MS, Alzheimer’s, Crohn’s, autoimmune disorders, etc.), and I can’t help but wonder whether my immune system might still be capable, over time and with continued nutritional support, of defeating and/or controlling whatever chronic infections I might have. At the age of 23, this doesn’t seem like an unreasonable expectation. What do you think?


  8. Hi Brendan,

    Controlling, yes; defeating, no.

    Usually the infection will lie low when your immune system is functioning well, and resurface when you are stressed, weakened, or older. Most of the common pathogens are very good at evading the immune system.

    I think on a good diet, antimicrobial medicines give you a good shot at a cure, diet alone merely improves the prognosis. I think on a bad diet antimicrobial medicines will usually fail.

    Of course, at 23 and with mild symptoms, you may wish to try diet only, and wait to try antibiotics until you have more evident symptoms, which might take decades.

  9. Thanks, Paul.

    Horror stories on various websites of people taking antibiotics for upwards of FIVE years and yet remaining ill have made me a bit gun-shy when it comes to exploring antimicrobial drugs. It seems like a rabbit hole of potentially life-destroying magnitude, and I simply cannot afford to spend the next five years of my life taking antibiotics of any variety, enduring significant die-off symptoms the entire time, and worrying constantly about whether the treatment is working (or is even appropriate). I’m at an age where such a lengthy, convoluted, and debilitating process is simply not a practical option.

    So I’ve continually returned to interventions that I know I can comfortably sustain indefinitely under almost any circumstances, like diet, supplementation, stress management, and sleep hygiene.

    From some other comments you’ve made, however, it seems that you believe that many chronic infections can be effectively treated with diet and antibiotics in 6 months or less, once the appropriate methods have been determined. Would you say this is accurate?

    On a personal level, do you think it’s likely that I, with a relatively youthful body and considerably milder symptoms than many, might be able to identify any significant pathogens and treat them effectively within a matter of months, not years?

  10. Hi Brendan,

    We’re at such a level of generality that I can’t really say; I don’t know your symptoms or your pathogen. I can tell you that 3 months of antibiotics made a huge difference for me.

    Of course, if you can diagnose your pathogens precisely then everything becomes much easier. You know the right medicines and you can use the diagnostic methods to tell when the therapy has succeeded.

  11. I’m referring mainly to members of the “Cpn-help” website, many of whom seem to have been on antibiotics, without much improvement, for years and years. Your experience is encouraging, however, because it seems to indicate that this may not be necessary.

    In my case, the only pathogens that have been identified thus far are gut parasites: whipworm, entamoeba, H. pylori, and campylobacter.

    My symptoms/issues include hypothyroidism, low cholesterol, rosacea, and depression/anxiety/insomnia and other brain-related problems.

    I’m working on treating the gut infections right now, but I can’t help but worry that these might be just the tip of the iceberg. I think that some of my symptoms suggest a systemic issue, or at least one that is not entirely confined to the gut. I suppose a diagnostic trial of doxycycline would be valuable in determining whether my brain symptoms are related to a bacterial infection. But I’m not comfortable doing this until my gut is certifiably healthy. And it’s possible that most of my symptoms might clear up once the gut pathogens are gone.

    Anyway, I’ll continue giving periodic updates on my progress. And if I do eventually manage to tackle all of these issues successfully, I’ll give you a nice thorough testimonial for your blog, because the PHD has been an enormous component of the success I’ve had thus far. So thank you. 🙂

  12. Hi Brendan,

    I think you’re right to focus on the known gut pathogens and eating a good diet. Getting healthy is like peeling an onion, you have to go one layer at a time. You don’t know to what degree your symptoms will disappear when you get rid of each pathogen. So get rid of the known pathogens and maybe everything will be fixed. If not, you’ll be better placed to diagnose what remains.

  13. Hmm…I thought I have automatically gut problems due to a leaky gut that causes my hashimoto disease? When I eat something bad like dairy or legumes I’m instantly getting slightly acne or at least at the next morning. Isn’t that a sign for a gut dysbiosis? By the way, I’m also trying to lose weight.



  14. From sweet potatoes I just get some spots. White potatoes are especially bad for my skin.;)

  15. Hi,
    is a 24h-fast/one meal per day even better for hypothyroidism than a 16h-fast/two meals per day? Especially in the winter?



    Hi Jasmin,

    Well, it’s not going to be better for everybody, but it might be better for some. If you try it, listen closely to what your body is telling you to decide whether it’s helping or hurting. And maybe get thyroid hormone levels tested after a bit.

    Best, Paul

  16. Hi JP,

    Yes, it is a sign of gut problems.

  17. The circadian rythms implicate also the same bedtime and get-up protocol every day. What about going out, for example or?

  18. Hi JP,

    I think it’s more important to sleep to a natural waking than to go to bed at the same time every day.

  19. Thank you for a great reference source for being able to get better health. If you ever offer on-site trainings, I would be very interested. Possibly for shopping, cooking, supplements, exercise, the whole gambit. I am a 58 yr. old menopausal retired RN, 5’8” 170lbs. I have Hasimoto’s, overweight, somewhat sedentary (no energy) and elevated lipid panel. From reading your book it seems as though I need to regulate the thyroid first before addressing weight and lipids, which may be corrected along the way. Some of the difficulties are HMO docs who seem to only what to address the lipids and put me on a statin (which I have not). After being in nursing for 23+ years I am very aware of the Big Pharma and how a lot of our docs are trained and nutrition uneducated. It is very difficult for me to persuade my primary (internist) to do any labs outside “the box”. When I went in for a checkup 11/11 (well women’s visit) I was told by the NP that I was a diabetic, which surprised me as no one had ever mentioned this; apparently on a BMP that was required for a diagnostic test the result was 129(FBS) (done in 10/10, wow and no one told me). I went to the drug store and bought a glucose meter and yes my morning sugars are 112-130 but (if there a but) my post prandial at 1 hour is 120ish and at 2 hours 106ish. Anyway, I am trying to remedy my health prognosis in a better direction; mom died at 62 of alcoholism and dad died at 62 CVD; mom drank and smoked during all of pregnancy and no breastfeeding…blessing in disguise? I have never researched nor tried Paleo before thus excited that these ideas are plausible. I have made a few meals from your book and I can’t believe how full I am. I am not very adept in the kitchen so any trainings would be favorable and if not maybe a dedicated cookbook. Again thank you for opening my eyes.

  20. There’s a comment on your book on about the dangers of feedlot meat and the benefits of its pastured counterpart. What do you say?

  21. “The circadian clock is strongly influenced by diet: indeed, food intake dominates light in setting the circadian clock. If you regularly eat at night and fast during the day, the body will start treating night as day and day as night. [1]”

    I think the above wording could lead to misinterpretation. I read the article as saying that food intake can effectively override the circadian rhythm, particularly if animals are hypocaloric. Certainly, this could mean that food also reinforces the light-day entrained circadian rhythms, but I don’t agree it can be read is saying that food dominates light, except under unusual circumstances.

  22. Hi Paul,

    i’m very interested in the protocol you laid out here (reminds me of Jack Kruse’s eating pattern). I’m wondering if there is anything that could be consumed before bed to ward off evening hunger and prevent nightime waking from hunger that would not disrupt the fast. This is esp. a problem for me because i train in the evenings and get hungry after a workout. How about a small amount of the food you mentioned in your Food for a fast article ? I was thinking something like some thin broth and MCT oil, or some BCAA + hydrolysed collagen powder + MCT oil?

    • Hi Rob,

      The natural way to do this is to make your post-workout meal and last meal of the day heavy in carbs. … That may put the meal at night, which is suboptimal, but eat as early as you can and get carbs.

      • Thanks for the reply Paul. Its a shame i have to train so late but i dont have a choice with my work patterns.

        So i should not worry about this pattern of IF, and just get some carbs and a small amount of protein in after training?

        How about a baked potato with some butter and / or cheese PWO?

  23. Thanks for this post!
    I have been doing this for a week now and it works!
    I was desperate because I wasn’t able to get asleep… I have two small kids so imagine how tired I was! But I was doing it all wrong. Now I skip breakfast, have an early lunch, some merienda at 17 h and dinner at 20:30. Then a cold bath at 22h and get asleep in 5 minutes!

  24. Hi,

    due to my hypothyroidism I go low blood pressure, especially in the morning. Would it be better to eat breakfast instead of doing intermittent fasting?


    • Hi JP,

      Yes, if your body is unable to maintain normal homeostasis during a fast, then don’t fast. But continue to work on fixing whatever pathology is preventing you from fasting.

  25. Jacquie Grimmond

    Hi there,
    this is all very interesting, I have been on the 16 hour fast for a month now, I have hashimoto’s. It is very easy for me to do the 11-7pm eating window, I also make sure I am easy healthy during that time, my problem is I haven’t lost any weight, does it take some time to kick in? Is this fast generally the best way to lose weight when you are struggling? Any help greatly appreciated, many thanks

    • Hi Jacquie,

      Weight loss comes naturally as you get healthier. You can force it by restricting calories, but it’s not clear whether that is a good or bad thing to do in terms of health. The more obese you are, the more likely you are to benefit from calorie restriction. If it is just a few pounds we’re talking about, I wouldn’t calorie restrict but rather focus on health improving steps (eg exercise, circadian rhythms, etc).

      Hashimoto’s is often preceded by gut dysbiosis, and that is associated with weight gain, so gut health is a good place to start. Also circadian rhythms.



    • Hi Holly,

      I don’t know enough about hormonal influences on this type of cancer to comment on specific thyroid hormone treatments, other than to say that I can see how TSH might stimulate growth of this cancer and why they would want to suppress TSH, but that excess thyroid hormone also stimulates growth of many cancers so the balance of evidence re what to do may not be entirely clear. I’ll leave that issue to your doctors.

      The one thing I can say with certainty is that proper circadian rhythms are extremely important for cancer prevention and recovery. So it is a very bad idea to work night shifts. I would try hard to get your employer to accommodate a day time shift for you based on your cancer.

      It is good that you are fixing your vitamin D issue but why with prescription D? Vitamin D3 is inexpensively available over the counter. Make sure they are not giving you D2 or an excessive dose. I think it is best to take a normal dose daily for circadian rhythm reasons. Actually, the best thing is to get ~2 hours of outdoor sun exposure daily if you can, exposing as much bare skin as possible.

      I think you should implement all the circadian rhythm tactics described in Chapter 42 of our book. Also be sure to eat some liver weekly, preferably chicken/duck/goose liver. This is a very important food for cancer prevention.

      Best wishes Holly!


  27. Hi Paul,
    I am a terrible insomniac, and I have been following the 16/8 eating schedule for a while now. I’m still reluctant to eat the safe starches because I have gut dysbiosis, but at the same time I think not eating them is affecting my sleep. My integrative Doctor wants to start me on the Dr. Brown protocol because I have lupus, lichen sclerosis, and hashimoto’s. He also wants me to go in hyperbaric chamber, and do IV nutrition. Do you think the antibiotics will help with the insomnia? Is it safe to do this regimen with SIBO? I want to treat these conditions in the best, safest way. I have not succumb to methotrexate or steroids and never want to.
    I love your work, and I’m always recommending your book!!!
    God bless,

  28. Hi Paul,

    is there any common chronic infections people with hashimotos can be checked for?


  29. While practicing intermittent fasting, is dark chocolate ok to consume in the 16-hour period? It looks like coffee and coconut oil are ok, so it would follow that chocolate is ok, except that most chocolate contains some sugar. Thank you!

  30. The article says a 16 hour night fast – 8 hour day feast protocol works best, but is exactly the opposite of what humans seem to have thrived on. According to Ori Hofmeckler, Nate Miyaki and other supporters of intermittent fasting, fasting from 2 hours before sleep( Let’s say from 22:00 ) to around 13:00 next day and feasting during the remaining hours is better. Thoughts ?

    • Doesn’t that match what Paul is saying…

      If i go by what you have written in you comment, then the Ori/Nate eating/feasting window is,

      example 1. from 13.00 to 22.00 = 9.00 hrs eating window (bed time = midnight)

      example 2. from 13.00 to 20.00 = 7.00 hrs eating window (bed time = 10 pm)

      • may as well add the example inbetween,
        the Ori/Nate eating/feasting window is,

        example 3. from 13.00 to 21.00 = 8.00 hrs eating window (bed time = 11 pm)

        • Let me make myself clear , because apparently I made a mistake. Paul says feast during daylight hours especially in the afternoon and fast during the night because the circadian clock says so.
          Ori Hofmeckler says undereat or fast completely during daylight hours and feast during night time but stop eating 2 hours before sleep, because the cyrcadian clock says so.
          It’s absurd ! Which one is right ?

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  33. Hi Paul,

    First, I am so impressed that you take time to answer all these reader questions!

    I have Hashimoto’s. Been following a low-inflammatory diet, relatively rich in fat and between 50-100 grams of carbs/day for several years and have seen great improvement to my overall health. I have long-lasting energy, sleep soundly for about 7-8 hours/night, very little chronic pain, good blood sugar regulation, and no more depression. My CRP went from 17 two years ago to 10 one year ago and I expect it will be lower when I get my latest lab results next week. I’ve lost 45 pounds, with about 100 more to go.

    My weight loss has plateaued, though, so I’m considering new regimes to see what might help with that. The 16-hour fast came up on Hashimoto’s 411 (a great Facebook support group) and I’m considering it. Before I began healing, I had to eat breakfast within 30 minutes of waking or I would experience headache, shaking, irritability. Now, I go several hours without eating breakfast…usually just ginger tea at 6am and then breakfast at 9am. If I go much longer, though, I frequently experience asthma and/or itchiness. I’ve assumed this is a sign my adrenals are stressed, but I’m not sure.

    Anyway…I’d love your thoughts on that particular symptom, but my question is more about timing of a 16-hour fast. I live in Portland, Oregon, at in the winter, it’s dark by 5pm and we usually eat dinner around 6pm. I stopped eating carbs in the later part of the day because that seemed to trigger early cortisol release and 4am wake-ups. I’m tolerating carbs better now, but still find if I overdo, I go back to that pattern. My preferred pattern is 9am hearty breakfast, 2pm light lunch, and 6pm simple dinner. Any reason why that 8 hours of eating would be less beneficial than the noon-8pm pattern?

  34. I wonder if you could address IF and adrenal fatigue as well, especially since AF is often seen with Hashimoto’s. I practiced IF in the past, but then heard it could stress adrenals. Thanks!

  35. Will PHD help to gain some weight to thin people?
    What cause a chronic constipation? and how to correct it. Thanks

    • Hi Eva,

      Yes – we’ve had many underweight people gain weight and muscle. For constipation, search on it in our Google custom search box in the upper right, or click on Constipation in the Categories > Diseases > Constipation list in the right sidebar.

  36. Hi Paul,

    I have a question for you sir. I have tried Keifers fasting protocl in the past…MCT oil in the a.m. and then eat about 4 hours later, so I had “fasted” for roughly 12-14 hours and backloaded all my carbs to the night. I lost quite a bit of fat but I noticed that my thyroid was affected and I had blood work done and it confirmed this. My question to you after reading this article is do you think that the I.F. had something to do with this? does carb timing matter when fasting and could taking in too little carbohydrate affect thyroid levels?

    Thanks for answering,

  37. Hi Paul,
    My daughter who is 19 just got some labs back and they show a Thyroid Peroxidase Antibody level of >1000! Her TSH is also high at 5.2
    We have not met with the dr. but I think he will want to put her on thyroid meds. What would you do with these numbers?? Is it ever beneficial to start a thyroid med to ‘get back to normal’ while also taking the selenium and low dose iodine?
    Thank you!

    • Hi Jenn,

      Yes, it’s almost always a good idea to take replacement thyroid hormone. I would take low dose iodine also. Selenium may not be necessary if you live in the US and eat beef/lamb/seafood and 3 egg yolks a day as we recommend. She could take selenium once a week.

  38. Paul, just want to make sure I understand correctly. Is the “fast” actually just a fast from carbohydrate and protein?

  39. Hi,
    I am having hypothyroidism. taking 50mcg synthyroid since 3 yrs. The hypothyroidism I got with pregnancy. My mom too have this condition. Recently getting lite muscle pains. After starting yoga it got controlled but didn’t disappear. I am confused. I really want to get healthy stopping the medication and follow some good principle/ concept that helps. Pls suggest.

    • Hi athidi,

      I would recommend reading our book and following our diet and lifestyle advice. Most people are able to gradually reduce their thyroid meds and eliminate them within ~2 years.

  40. I’m turning fifty in a couple of weeks, am going through menopause, and am hypothyroid (on 100 mcg Synthroid). I’m considering doing a 72-hour fast to try to reset my immune system as described in this article ( I’m also hoping that it might help me break through a 2-year weight loss plateau. Do you think a 3-day fast could help me? Do you think it particularly risky? What effect, if any, do you think it might have on menopausal symptoms such as hot flashes? I realize you can’t give medical advice, but am curious whether you would warn against such a fast.

    • Hi Mary,

      I don’t recommend that, especially if you haven’t previously been intermittent fasting. I would recommend doing 16 hour fasts daily, maybe once a week increase it to 23 hours, but eat normal amounts of food daily.

      There are risks to stressful fasting. It is usually not necessary to go to such extremes to get the benefits of fasting. Consistent practice of overnight fasting is more important than an occasional long fast.

  41. I’ve seen it on here before but can’t find it again, can someone please remind me what the PHD recommends as correct TSH level to aim for.

    • Hi Shaz,

      It depends somewhat on personal context / health status but it will always be in the range 0.5 to 2.0. People with superb health tend to be around 1.0. Elderly tend to be around 1.5.

  42. gosh thanks paul
    my tsh wax 0.01 last june then it jumped to 8.28 in October. I’m lost as to why and my gp is puzzled too. im awaiting results of my latest bloods this week but unfortunately i just don’t feel we’ve got it under control yet!!

    • Hi Shaz,

      That’s a common pattern. You had a severe thyroid injury which impaired the function of most of your thyroid, and also created a nodule that made you hyperthyroid through uncontrolled formation of thyroid hormone. As the nodule healed, you were no longer hyperthyroid but still have the damaged thyroid, so now you show as hypothyroid.

      You have to treat the hypothyroidism and just keep healing.

  43. thanks so much for responding Paul. so by treating the hypothyroidism do you mean by taking the right dose of levothyroxine to get my tsh levels stable? i struggle with very low energy levels and food cravings where all i want to eat is wheat and sugar and chocolate it just feels out of control which sounds silly! I’ve been following PHD which works then suddenly the cravings are back and my eating is out of control again!! i do feel muddled 🙁

    • Hi shaz,

      Yes, although in severe cases such as yours seems to be there is often benefit in taking T3 as well as T4.

      Hypothyroidism usually originates in the gut so you need to address gut health. Work on immunity (liver/spinach/sunshine/circadian rhythms/intermittent fasting/iodine), wound healing (bones/joints/tendons + vitamin C), and other gut flora improving steps.

  44. thanks Paul, here in the UK its near on impossible to see a doctor who seems to understand the thyroid they just dish out levothyroxine. do you have any advice on how to find a specialist in this field please?

  45. hi paul,

    Im glad i came across this site… Do you know much about going low carb diet and then having your thyroid malfunction? and would it be good it intermittent fast while trying to heal from this?

    I tried a very low carb diet abruptly for 5-6 weeks – i began to lose hair, ive gained about 15 lbs and counting, can’t fit in my clothes i was constipated for days and just felt awful.

    I then began to add carbs back up about 8 days ago, im less constipated but am still gaining weight and am still tired. im supplementing also and eating more iodine

    Is intermittent fasting 16:8 a good way to re boost my thyroid function… or is it going to make it worse?

    any help is appreciated!

    • Hi Ocean, We’ve written extensively on low carb diets and the thyroid. Click on the hypothyroidism category,, and read the various posts.

      Low-carb diets decrease levels of T3 thyroid hormone and therefore tend to exacerbate hypothyroidism. It’s not uncommon to experience hypothyroid symptoms such as hair loss and constipation when the diet is too low in carbs.

      Intermittent fasting is good for your health and good for the health of your gut, so ultimately it will help the thyroid, but don’t expect an immediate fix.

      Best, Paul

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