Nutrition with an underactive thyroid

Hello all. I'm new and hoping you can help me or signpost me to good resources for nutrition ands weight loss. I have been trying too lose weight since the birth of my second child and that was a catalyst for my diagnosis. I was diagnosed in Feb, prescribed 25mg of levo and was with a personal trainer and couldn't lose weight no matter how many different levels of calorie deficit I was in. I just gave up after that. Especially as some personal trainers are cynical about the thyroid having any effect on weight loss. I am now on 50mg and exercising/weight training like crazy but not getting anywhere. I would like to be able to get info and advice about calories/macros and what I should be eating. Can I ask for a dietician referral? I need to lose weight fast as my family history includes type 2 diabetes and heart disease.

29 Replies

Forgot add a thank you

First thing is do you have any actual blood test results? If not you need to get hold of them. You are entitled under data protection laws.

You may be able to view test results online - ring and ask about this. If you can then apply for online access to your account. All GP practices are supposed to offer this, in reality very few have blood test results available online.

If not then ask for print out of recent tests. Pick up in a day or two. They may make a nominal charge for paper.

You need to know results for TSH, FT4 and FT3.

Do you also have high thyroid antibodies? You need to know. Did GP or Endo ever test these? If not ask that they are tested.

If your antibodies are high this is Hashimoto's, (also known by medics here in UK more commonly as autoimmune thyroid disease). About 90% of all hypothyroidism in Uk is due to Hashimoto's

With Hashimoto's, until it's under control, our gut can be badly affected. Low stomach acid can lead to poor absorption of vitamins. Low vitamin levels stop thyroid hormones working.

Essential to test vitamin D, folate, ferritin and B12. Always get actual results and ranges. Post results when you have them, members can advise

Exercise really uses up T3, so until optimally medicated, it can make you worse.

50mcgs is a starter dose. Likely under medicated

I think that just might be 'optimally medicated', not 'optically'. lol

I like the look of my food, so opticallly functionally medicated works for me. 😀 🌶🍎🍊🥑🍆🥕🍅🥛🍵🍫

Maybe if I tried to consume through my eyes I would have better look.😂

My advice? Stop fretting, eat more and exercise less! You're making things worse, the way you're carrying on. :)

Forget calorie-counting. It's a very un-natural way to eat. Concentrate on nutritional content. There is no magic diet for hypos, just eat good clean food. No processed foods but don't freak out about a little sugar from time to time. And don't do crazy things like cutting out salt! On the other hand, make sure that no unfermented soy ever passes your lips. It's not even food.

This is what happens : you go on a low calorie diet, and your body slows down your conversion of T4 to T3. You are hypo, and taking T4 only, so your only source of T3 - the active hormone - is conversion of T4, and that takes a lot of calories. You then go to the gym and 'exercise like mad', and use up all your calories. So, conversion stops. And, then, the exercise uses up what little T3 you've got, which you can't replace because you've got not calories, so you get more and more hypo, and put on more and more weight. Result! Not.

That's what being hypo means : low T3. T3 is needed by every single cell in your body to function correctly. If there's not enough to go round, then all sorts of weird symptoms occur. On of the symptoms is putting on weight and having difficulty losing it. But, who ever said that weight-gain was fat? More than likely it isn't. Hypos get this delightful substance called mucin, that snuggles up under the skin and absorbs water. Lot's and lots of water! And water is very heavy. And no amount of starving yourself, or killing yourself at the gym is going to get rid of it. Why would it?

You are only on a starter dose : 50 mcg. How long have you been on that dose? When did you last have labs done? Do you know the results? Did you get a print-out of them? If not, get one, and post your results here, with the ranges. You have got to be under-medicated on such a low dose, so what chance weight-loss? None. These things take time, I'm afraid. Hormones have to be started low and increased slowly. And doctors know little about hormones, and often don't understand the necessity of increasing doses. I'm afraid you have got to learn about your disease and how to treat it, and how to look after your new body, which isn't going to react like a healthy body, anymore. And, it needs more calories than you're giving it at the moment, to be able to cope with these new challenges it's facing. So, be kind to yourself and forget this obsession with your weight. It will come. With time and correct treatment you will lose the weight. But, with hypo, any attempt at short-cuts just ends up with you back to square one. Patience is the key word, here. :)

Hi Greygoose....i am new to this forum too....and always appreciate your straight forward advice. I have been struggling with chronic fatigue for a few years put it down to menopause...I’m 53.. in April this year I went to Docs because I felt so depressed. Luckily for me the doc took bloods and confirmed that I had underactive thyroid, she said my results ( I didn’t ask for them) showed that I had possibly been overactive and now I had burnt out my thyroid.....being new to this I had absolutely no idea what she was talking about....she put me on a starting dose of 50 levothyroxine.....and an appt for 4 weeks....I went back still feeling the same, if not more tired and depressed....the levo was increased to 75....I had other symptoms of a persistent cough and was choking on got a referral for an endoscopy... they took 4 biopsies from duodenum and bloods .4 weeks later still exhausted was diagnosed with very pronounced Coeliacs. So I’ve been trying to eat gluten free for the last 2 months.... i had lost 6 kilos on initial diagnosis of hypo...and have started to gain weight quickly since removing gluten..... I haven’t had bloods taken again as she said to leave the dose at 75 as my small bowel would soon start absorbing nutrients and medication and that I’d then be right as rain. I went back to work a month ago, and now I am exhausted...I wake up late...and go to bed as soon as I get home.. I need to go back for a check up.....but I need to know what to say as she can be very dismissive...and would again fob me off with it will take time.... blah blah ... my fingers and toes are freezing and sore all the time and she said I possibly had white finger...she said auto immune disorders hunt in packs....I was advised to take folic acid and vit D....I .have muscle fatigue ..I’m out of breath and feel my lungs are going to burst going upstairs...or feel faint when I get up from a chair or get out of bed... can you advise me what to say to my doc....sorry I don’t have the numbers...I a bit of a wimp when it comes to crabbit doctors....

Hi CS1964, welcome to the forum.

I'm afraid you're going to have to post this in your own thread - just copy and paste - because it gets so very confusing when people piggyback on other people's threads. And, this question, I imagine, will entails some detailed explanation and other questions, and it's not fair to do that on someone else's thread. So, just start a new thread, and people - not just myself - will be happy to reply. :)

Try NDT you should then get back to your correct weight.


Before being diagnosed with an underactive thyroid I had noticed a weight gain and despite running 15km a week at the gym couldn't lose any weight. I believe I have Hashimotos as my antibodies were found to be high. A friend recommended I go on a gluten free diet as apparently gluten attacks your thyroid and its now almost two years since doing so. I have lost some weight - I don't know if this due to the gluten free diet - but most importantly I feel I am maintaining my current weight without even exercising. If you look on this website you will see that lots of people recommend a gluten free diet for reasons other than weight loss. A gluten free diet may seem daunting at first but it is now second nature to me and it helps if you like cooking.

No, gluten doesn't attack the thyroid - let's be quite clear on that, before the rumours start to fly! :) Gluten contains a protein - forget the name - that is similar to the make-up of the thyroid gland, and incites the immune system to attack the thyroid. Without the gluten, the immune system calms down somewhat. That's why it helps. :)

Oh yes! That's right. Thank you, BH. :)

Follow greygoose advice I've stopped running only walk now, I've cut out gluten and I eat as much as I want fruit veg fish etc good fats coconut oil olive oil avacado, I've lost 21lb in seven months, I found izabella wentz books useful too.

Just book marked her website. Thank you.


I agree with the comments that say stop the calorie counting. Concentrate on getting maximum nutrition, minerals and trace elements into your body. The fact we developed a disease means we were lacking things the body needed to keep fully repaired.

Important to eat good fats, especially coconut oil, organic butter and extra virgin organic olive oil. Lots of info out there about why that works. The body works on fats. The brain is made from cholesterol. Do cut down on sugar and starch, especially cakes, biscuits, bread etc, it is those that build fat stores in the body. Proper fats get used.

I had accumulated 3 extra stone and with my son's wedding only 4 months away I lost it by replacing 2 meals a day with a SiseLean protein shake (organic, no soy, still has the active . 5 years later some has crept back on and I have just started to use Sisel Ript, because I want more muscle after an inactive time. See both at

Toxins that are harmful to us get stored in the liver and the fat cells. So do you use shampoos and personal care with sodium lauryl/laureth sulfate? Children are now born with more than 300 of these toxic chemicals in their fat cells. I benefitted by cutting all the toxic stuff out and swapping to lovely, effective safe stuff, again Sisel.

Hi :) I agree with the other comments about focusing on good nutrition first and foremost.

I too have a family history of heart disease, have high cholesterol, and also always felt like I would become diabetic as I would go 'floppy' if I didn't eat every two hours! I went on a low carb high fat diet ( is a pretty good starting point for info) and lost 2.5 stone without eating any less food.

Recently I've started learning more about the thyroid connection. And apparently a low carb diet can not be the best approach for low thyroid, so I have upped my carbs a bit.

Also I believe T3 can 'run out' with heavy exercise - had this happen last week and it took me all week to feel vaguely human again! - so I'm not sure intensive exercise is the best route forwards for you.

Since finding out about the link between high cholesterol being caused by hypothyroidism - and subsequently finding this wonderful forum and all the fabulously knowledgeable people here :D - I have increased my thyroid meds and lost another half stone without trying.

So, I'd focus on getting your thyroid sorted. Definitely ask for a print out of your most recent test results as there are some really great people here who would be able to advise you. And, if the last test only tested TSH, it's worth paying for a private blood test to get a proper thyroid panel test done, which would include TSH, T4, T3, reverse T3, and thyroid antibodies.

Good luck! and here's to your health :)

Will I have to go private for a full thyroid panel. I imagine my doctor would be reluctant to do so when my TSH and T4 are in a good range. I couldn't do very low carb. I had a month of it with the Body Coach and it was horrific. I was evil and nearly crashed the car a few times. Another good low carb/keto website to google is Fit Men Cook

Thanks folks for your advice. Probably should have put more context around it.

I lost my baby weight by doing the Body Coach in Jan 2016. When that finished I was weight training and counting calories and macros as I want to be lean but muscular and strong. I got to December 2016 and had hardly lost any more weight. Staying roughly the same. That was from trying everything...a range of cals from 2200 per day to 170". Different exercise splits from 5 days to 3 days a week.

By last December I was displaying other symptoms too and my husband thought it might be hypo as it runs in my maternal line (mum was diagnosed at 50 but should have probably been diagnosed earlier, her mum died of something heart/myxodoema related, mum's cousin has it'.)

I had a blood test between Christmas and NY and my TSH was 5.01 and T4 was 11.9. Because it was borderline We had a retest 4weeks later and my TSH was 3.90 and t4 was 12.5. The doc wouldn't do anything so a few weeks later I got a second opinion from the practice lead. He said that the bloods may not clinically say it but my his and symptom do so we'd test again and do a low dose. Test in early feb said 4.11 and 13.6. Retest in lateMarch after nearly 2 month of 25mg said 3.36 and 16.1. I've had my antibodies checked twice and they're fine.

In Feb I started with a PT who gradually dropped my cals again. Over 3 months from 1800 to 1500 and we did a lot of metabolic workouts which are high intesity. In fairness he didn't know about the condition and I am probably as clueless. After 4 months I decided to pack it in as the food and last of weightloss was making me miserable. I went to the doc and explained that I still had symptoms and the lack of weight loss and asked to be put onto 50mg. The results from the follow up test (I haven't got them to hand) were something like 1.6 and 18. By that stage I had stopped the gym completely and was eating pure cr@p.

I have started back at the gym because I love it. If I go first thing it sets me up for the day and it really helps stabilise my mood. I went back up to 1750 cals a day and trying to take it from there but I just feel like I am stuck. I wouldn't want to give up exercise especially weight training which is my love.

I am not desperate to lose weight because of looks but of health reasons. My mum has so many health problems now because of being at least 5 stone over weight and having her hypo uncontrolled. She also has high blood pressure and cardiac problems. My dad had type two diabetes which runs in his family and the women on his side have heart attacks. If I can't get a handle on this I will get to 70 and be a wreck. I want my children to not have to worry like I do.

I just can't seem to find anything with an evidence base or PT and nutritionists that have a thyroid specialism. The PTs I see are cynical that cals in vs cals out don't seem to work on those of us with hypo. I can't work out if anything I am doing is right because nothing changes when I make changes (I try to give a good 4 weeks before I make changes so it has time to work). I also feel rubbish about it and the fact that I have not been as poorly as some people to get diagnosed.

It feels like nothing is geared up for us.

Did you actually read my response above, explaining how it works? You are still trying to treat your body as if it is a normal, euthyroid body; But it isn't. The rules have changed since you became hypo.

Do you even know your FT3 level? Do you know how well you convert? Without knowing those things, you are not going to get anywhere. If your doctor won't give you all the tests you need, you can do them privately. Details of private tests are on ThyroidUK main page.

I am starting to understand that from reading the thread. I know I need to do my homework and get some more tests.

Hi Elmear 78,

I am a personal trainer with Hashimotos, so understand how hard it is to lose weight and become healthy. It really is a combination of eating a healthy unprocessed diet and getting your medications, vitamins and minerals to the correct levels for you. For me to lose weight I have had to go on a very low carb diet. My average carb intake per day is 80g per day or below, so really I eat a lot of dark green vegetables. Along with this I have amended my medication dose and taking supplements. Currently I have lost about 8% of my body weight going down from 80kg to 72kg, but more importantly this has mainly come from fat as my muscle mass has only reduced by 1.2kg.

So far my personal experiment is positive, but I could not have done this with out the help and support on this web site.

What I would say is that this condition does effect people differently and a solution for me may not be the same for another person, but it is about trying different suggestions until you find the right one for you.

I have really struggled with low carb in the past. I lack concentration and I am so irritable. The last cycle of the Body Coach I nearly crashed the car a few times.

I am fed up of struggling to get it right. Am I over exercising?Run two days and weights two days.

Take a look at HU’s Healthy Eating forum, also read SeasideSusie’s excellent responses re nutrients, & maybe take a look at Chris Kresser’s functional medicine site re diet & probiotics.

Thank you. I have never come across him before.

Just posted some of his gluten links further up.

I really like his dietary advice, even though it contradicts my eating habits as I'm veggie.

I need a few hours and a good read.

Hi everyone. Thanks so much for your advice and guidance. I have dug out an old journal and started making notes from this and other threads and tomorrow I am ringing the docs for all of the results and to request another full panel and vitamins with ranges. If they won't give it to me I will get a private test. I will start there and let you know how I get on.

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