How to lose weight when you are hypothyroid

How to lose weight when you are hypothyroid

If you are hypothyroid, you know all about the swollen, lumpy, heavy fat that seems to pile on your body, especially your belly, overnight.

Written by Sophie Anson & Dr. Hugh Melnick

Thyroid function & body weight  

Anyone with a low thyroid function knows that losing weight feels nearly impossible. Some of us try starving, some of us are exercising excessively despite a distressing lack of progress, and some of us have simply given up. Before I was diagnosed as Hypothyroid, I was doing all of the above.

The thyroid gland produces hormones that ultimately control a person’s metabolism, which is the way in which the body burns calories to provide cellular energy. When our thyroid hormone levels are low, calories are not burned effectively, resulting in weight gain even when very few calories are consumed. You might feel as though everyone around you eats normally, without consequence, whereas you eat very little and yet continue to gain weight. Water retention also tends to be high.

Ideally, treatment with thyroid hormone increases an individual’s metabolic rate, thereby increasing the amount of calories that are burned which results in weight loss. In most cases, however, treatment with thyroid hormone alone cannot entirely correct metabolic problems and relieve symptoms. Simultaneous nutritional therapy is essential to maximize weight reduction and eliminate many of the troublesome symptoms that plague people with low thyroid function.

Low thyroid function frequently occurs when the body becomes “allergic” to its own thyroid gland. The confused immune system forms antibodies against its own normal thyroid tissue, killing off the thyroid-hormone-producing cells, resulting in low thyroid function. This situation is called autoimmune or Hashimoto’s thyroiditis. Antithyroid antibodies rarely disappear, but with life-long treatment via a combination of thyroid medication and dietary modifications, symptomatic relief and the maintenance of a healthy body weight can be achieved.

If ever a person has been challenged with weight gain, it is someone suffering from an underactive thyroid. Prior to being diagnosed, I observed my own weight creep up slowly but surely, despite strict adherence (I am a nutritionist after all) to what I believed would be a fat-reducing diet. Frustrated, I consulted with two doctors who wanted to prescribe antidepressants, despite my insistence that my “wanting to sleep all day” wasn’t a euphemism for wanting to commit suicide. Finally, I was diagnosed as hypothyroid by an endocrinologist and put on Synthroid. When asked how to manage  weight gain, I was told to “start eating like a woman”. By that she meant eat no more than 800 calories a day and to drink my coffee black.

I wasn’t going to do that, and neither should you, as it is unhealthy and potentially dangerous. As a nutritionist, I know (and everyone knows) that 800 calories a day is not sustainable (although I do have a number of overweight hypothyroid clients who eat less than this). That was not a path I was willing to take. I am willing to work harder and eat cleaner than those who do not have a thyroid issue, but I am also a confirmed foodie, and I wanted to eat proper meals. There had to be a better way.

So, how to lose weight when Hypo. Warning: It will be slow. It took me 20 months to lose 20 lbs, but the alternative was 20 more. A year and a half later – I’m glad I never gave up. Losing weight this slowly can, with the normal fluctuations that occur during weight loss, (especially if you are a pre-menopausal woman) make it appear that no progress at all is being made after a month or two. It’s crucial to watch the trend, not the actual number and as I tell my clients: to chase the low. What I mean by that is: keep looking for the next new low (no matter the fluctuations in between, and no matter how small they might be).

Key steps to thyroid weight loss 

Watch your insulinLosing weight has far less to do with watching calories than it does with watching insulin. Insulin, a hormone just like T4, T3, melatonin, testosterone or estrogen, is the hormone used to lower blood sugar, and store body fat. If Insulin is the bear, when the bear is poked (by eating carbs, i.e., sugar), we gain weight. In the absence of insulin, we lose, even if calories are high. This is why cutting calories does nothing, if the calories that remain are poking the bear. Don’t poke the bear!

Be patient and tireless in your quest to find the right medication for you. I was put on Synthroid, then Armour, then Synthroid and Armour, then Nature Throid, then generic T3, then generic T3 and Armour, then Cytomel. I am now on a T3 only protocol. I’m not the only one. Find a doctor who is willing to keep working with you. It took me two years to find the right medication and dosage thanks to an amazing doctor who never gave up on me.

Eliminate Gluten. Even if you don’t have Hashimoto’s. Even if you have “no adverse reactions”. Eliminate gluten. There are no universal rules except this one.

We burn a greater percentage from fat when we sleep than during any other time of the day (including when we exercise), so skimping on sleep will thwart your weight loss efforts. If you are having trouble sleeping, talk to a doctor or nutritionist for tips on how to get or stay asleep.

Lift weights, but don’t do excessive cardio. One of the ways we lose weight when Hypo is by losing lean mass (muscle mass) which is not a good thing. This is due to two things: 1) we are exhausted, and therefore moving and lifting less and 2) some medications (such as t3) are catabolic, meaning they break down both fat and muscle indiscriminately. Weight lifters who take t3 to cut fat also take steroids to preserve muscle (this is a very bad idea!). It’s essential to preserve and indeed gain lean mass while trying to lose body fat, as our lean mass supports our metabolism. Excessive cardio can actually make it harder to lose weight. Lift weights over running.

Have your Iron, D3, Selenium, B12, Ferritin, Folate, DHEA, Estrogen, Progesterone (including men) and testosterone (including women) tested. Make sure they are optimized and not merely “in range”.

Find a doctor who will treat your symptoms, and who examines your bloodwork only within the context of these symptoms. Before I met my current doctor, I saw doctors who would ONLY prescribe Synthroid and told me the weight gain was age related (I was 39). If your doctor only talks about your TSH, run. TSH testing is outdated and much too broad, and yet some doctors will ONLY test this hormone. You need a complete panel: Total and free T3 and T4, TPO and Tg thyroid antibodies, T3 uptake and reverse T3. If they are “in range” and you still have symptoms, you need to further adjust your medication.

Don’t believe that you have to eat 1000 calories a day or less to lose weight. If you are properly medicated, this is simply not true.

Be fanatical when it comes to grass fed meat, wild fish, pasture raised (NOT free range) eggs and organic dairy. The hormones and antibiotics used in conventional farming and dairy get passed along to us. Thyroid hormones are hormones, and are affected by such practices.

Don’t drink too much alcohol. Alcohol is sugar. Sugar triggers insulin. Remember the bear. 

Never assume that the Paleo, Keto, Vegan, EatStrong Plan a friend is following will work for you. Just because a friend feels great on Synthroid and eats gluten, don’t assume it will work for you, even if you are similar in every other way. Most of us need a personalized approach to medication and nutrition.

Regardless of the plan you choose to follow, stick to this rule, and you WILL LOSE WEIGHT: Eat more fat, more protein, and less carbohydrate. Dietary cholesterol has a 0% impact on blood cholesterol. Saturated fat has no impact on heart disease. Sugar (carbohydrates) affect both cholesterol and heart disease. Eat more fat, and more protein. Bacon and eggs for breakfast, burgers with avocado for dinner! When including carbs (but try not to do so) focus on Round-Up-free (organic) veggies, sweet potatoes, and oatmeal.

Avoid fruit if you are trying to lose weightI know. Am I crazy? But fruit is so healthy! Yes, it is, if you don’t have weight to lose. But fruit triggers insulin just as does a cupcake. It has exactly the same effect on your insulin as a pack of gummy bears, so while full of healthy vitamins and antioxidants, don’t think you can lose weight if you are eating fruit. You can have plenty of fruit once you reach your goal. I gave it up for two years and eat it every day now. Everyone fights this concept, and I know it’s hard, but you will be having fruit again soon. The exceptions to this rule are avocadoes and olives. You may have both.

Speaking of avocados, eat one every day. Or two. Remember – we aren’t counting calories. A burger or two topped with avocado and bacon makes a great dinner.


Do not believe that you are destined to be heavy, are the exception to the rule, “can’t lose weight”, or are too old, too female, or too tired to lose weight. Everyone can lose, including you. If you feel you need support, enlist the help of a competent nutritionist with whom you feel connected, until you have the confidence to work alone.

Losing weight when hypo is undeniably harder than is losing weight with a perfectly functioning thyroid. Yet so many things that are hard are worthwhile. Try to view the journey as something exciting, a tremendous challenge, which you will be proud to overcome. Try not to dread the process. You will NOT be hungry on the right plan. Losing weight will give you a profound sense of accomplishment, and you are worth the effort.

About this Nutritionist/MD Thyroid Team

Sophie Anson is the Founder of Eatstrong, a multifaceted wellness company in New York City that has helped hundreds of people achieve their personal goals in terms of weight, fitness, health and overall wellbeing. Originally from Switzerland, Sophie came to the US in 1992 to attend Hamilton College, where she earned a bachelor’s degree in psychology. Struggling with her own weight, she later obtained her American Council of Exercise certification as a nutritionist.

Dr. Hugh D. Melnick, MD, is a reproductive endocrinologist who has been treating patients with hormonal and fertility problems in NYC since 1976. He began to notice the number of infertile women visiting his offie who were symptomatically hypothyroid. They would go on to finally conceive after treatment with thyroid medication. Dr. Melnick’s vast clinical experience together with his own personal experience having hypothyroidism himself has enabled him to develop a unique approach to the diagnosis and treatment of hypothyroidism. In addition to his fertility services, he works with women and men with hypothyroidism at

READ NEXT: Are you living life with thyroid brain fog?

Take Back Your Thyroid Health! Sign up and never miss a post - it's FREE

About Dana Trentini

Dana Trentini M.A., Ed.M., founded Hypothyroid Mom October 2012 in memory of the unborn baby she lost to hypothyroidism. This is for informational purposes only and should not be considered a substitute for consulting your physician regarding medical advice pertaining to your health. Hypothyroid Mom includes affiliate links including the Amazon Services LLC Associates Program.


  1. Jody Holmes says

    My doctor put me on Naturethroid since the T3 was still low on Levothyroxine. However, I don’t feel as good and would prefer to go back on Levothyroxine. My TSH is .9, which is in range but I felt better when it was .4. I doubt my doctor will increase my meds.

  2. I’ve heard that cabbage, broccoli and cauliflower should be avoided by people with hypothyroidism. It affects the use of iodine by the thyroid. Is this true.

    • Hi Sylvia, The concern with goitrogenic foods is in cases where people are eating large quantities of raw goitrogens, such as when placing large amounts in smoothies. Cooking including steaming goitrogenic foods reduces the goitrogenic effect. I do not eliminate these nutritious vegetables from my diet but I do limit the amount of raw form that I eat and I do steam whenever possible. Good to have you at Hypothyroid Mom.

  3. Hello, I had Thyroid Cancer almost 11 years ago. They took out both and was doing fine for awhile but they had to play with my meds and now I am on 100mcg. I work 5 days a week on my feet all day and by the time I get home I am just exhausted. I will be 56 in November and I just want to lose the weight. I don’t drive so walk almost everywhere but can’t lose. It seems I gain overnight, what can I do??? Thank you for listening

  4. I had hyperthyroidism that went out of control and caused severe heart failure. God saved me. I almost died. I had my thyroid removed shortly thereafter. It’s hard because I went from a size 10 to a size 18 to 20. This was in 2.5 years. Since exercising with weight lifting i went down to a size 14 in 6 months but its hard to stay there. I go to dr all the time for my thyroid testing and am having a very hard time losing weight. I do eat some sugar and fruit. I think you may need to find out what and why you have hyperthyroidism before it’s to late it and resolve the underlying causes. If medication cannot bring bring the hyperthyroidism under control then dont wait. Uncontrolled high hyperthyroidism causes heart failure!

  5. Eileen carter says

    Iam 80 years old and still get hot flushes since my menopause.i also have under active thyroid.and take thyroxine .are the too connected ?

  6. Janice Raney says

    I hope you answer this question. How does HCG fit into the equation? Every other year,
    I do the HCG injections for 8 weeks so that my 500 cal. a day on a very specific diet of minimal amounts of allowed foods works. I’m 82 and have been doing this diet sporadically for 48 years. I feel better and am not hungry when injecting this HGC hormone. It worked better in the 70’s and early 80’s when it was a natural serum made from the urine of pregnant women. The FDA got involved, and now it is a synthetic serum that isn’t quite so perfect, but maybe that’s because I am so much older. Please respond. Thank you

  7. Evelyn Murphy says

    How do you “watch your insulin”?

  8. I disagree with fruit being cut out of diet, as fruits are healing and nutritious and not to be compared to a cupcake, where is the logic in that? Doctors who say things about nutrition and do no seem to be really educated on that particular topic, , shouldn’t be able to spread this type of information as its passed on to people who do not doing any research and say it because a doctor said so.
    To Rachael, I would find more information on that, doctors who think or say things like this do not seem to be listening to the patient or their concerns. Thyroid meds can also cause osteoporosis…I believe there are ways to get off the meds and i am researching that , for myself too!

    • I don’t have a thyroid, and I really limit fruit. It helps – I don’t cut it out completely, though. Thyroid meds can cause osteoporosis if you are on too much for a long period of time.

  9. Hello I have hyperthyroidism I been on
    Methimazole for like 10 years my endo doctor; says I should have my thyroid taken out cause either way gonna be on medication .She said over long time usage it can affect liver;My numbers been good and I feel fine ,should I still schedule the surgery for it to be removed or wait .im not sure what I should do ..cause once removed will I feel worse ??As I’m seeing reviews??What fo you guys think??—Rachel

    • Yes. I had hyperthyroidism and was on methimazole for two years before definitive treatment. Methimazole can cause immune system suppression and an overactive thyroid can cause heart, kidney and liver damage. Go ahead and schedule the surgery in my opinion

    • Amanda Dodson says

      Rachel, I had hyper for over a year and I was miserable. methimizole didn’t work for me. I didn’t have surgery, my doctor gave me the option of nuking it with a pill. It was really easy and I have been on levo ( thyroid replacement med) for almost a year now. It takes a while to get it all even out and obviously now I am hpyo, which has its own set of issues but, i will tell you i feel a million times better then when i was hyper.

    • Search on the benefits of Iodine and Selenium, they will help balance your Thyroid.

Speak Your Mind