How Eating Disorders Cause Thyroid Problems - HPA Dysfunction

How Eating Disorders Cause Thyroid Problems – HPA Dysfunction

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The Connection Between Eating Disorders and Thyroid Problems

You probably already know that the foods that you eat have a powerful impact on thyroid function, which is why you can change your diet to treat your thyroid. 

But did you know that your eating BEHAVIOR also has an impact on your thyroid gland?

I'm talking about the behaviors associated with certain eating disorders such as anorexia and bulimia. 

If you are someone who has struggled with one of these eating disorders in the past then you probably already know what I am talking about. 

These eating disorders can have a profound effect on thyroid function such that they can cause uncommon thyroid lab patterns, a reduction in metabolism, and damage to your hypothalamus. 

Today you are going to learn:

  • How eating disorders impact your thyroid gland
  • How these eating disorders cause damage to your BRAIN and not the thyroid gland
  • Why it can be tricky to diagnose these problems using standard thyroid lab tests
  • How eating disorders indirectly affect your thyroid gland
  • And more...

Let's jump in:

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How Eating Disorders Damage your Thyroid

It's important to first point out that when I refer to eating disorders I am referring primarily to anorexia and bulimia. 

I am not referring to eating disorders such as food addiction (1). 

The reason I am focusing on these eating disorders and their impact on thyroid function is that they tend to be overlooked by many physicians. 

Most doctors (and perhaps even some patients) fail to recognize the downstream effects that eating disorders have on hormone balance, thyroid function, metabolism, and long-term health (2). 

At the basic level, they probably understand that these things do occur, but they fail to understand how they change or impact treatment decisions and how to help patients recover from these consequences. 

As someone who has had an eating disorder in the past, it's important for you to completely understand how it is impacting your thyroid. 

Having this understanding will help you when it comes to management and treatment. 

I should also point out that I learned much of this information in helping my wife who struggled with an eating disorder in her early life. 

What I didn't realize at the time is that eating disorders tend to cause issues that persist LONG after the damaging behavior has stopped. 

In her case, she suffered from mental changes, a suppressed metabolism, and low T3 for many years even after her eating habits returned to normal. 

With this in mind, let's talk about how eating disorders can damage your thyroid: 

#1. Disruption to the Hypothalamic Pituitary Thyroid (HPT) Axis

The first, and probably biggest, issues stem from the impact that your eating behavior has on your brain. 

And when I refer to your brain I am talking about 2 organs that communicate closely with each other: your hypothalamus and your pituitary gland. 

These two organs form the backbone of a complex hormone system that communicates and receives feedback from the hormones that your body secretes. 

In the case of the thyroid, the hypothalamus communicates with the pituitary gland which then communicates with the thyroid gland which then communicates back with the hypothalamus in a feedback loop. 

Something similar also occurs with your adrenal glands, ovaries, and testicles (if you have them). 

What you need to understand here is that there are certain stimuli that can cause problems in this hypothalamic-pituitary system. 

One of those stimuli comes from eating behaviors. 

A history of binging and purging or of continued caloric suppression sends signals from the body to the hypothalamus which suppresses the normal feedback loop I just explained. 

This stimulus manifests as hypothalamic suppression (3). 

Put in simple terms, it causes the hypothalamus to send fewer signals to your pituitary and thyroid gland. 

This results in decreased thyroid function and a decrease in circulating thyroid hormones such as free T3 and free T4. 

It's not clear exactly what causes this suppression as it may come from the fat cells or other cellular messengers, but we do know that it does happen. 

This isn't the only system damaged if you have a history of eating disorders, by the way. 

Some women also experience disruption in their menstrual cycle or something called amenorrhea which is an absence of the menstrual cycle. 

The same problem that causes the menstrual irregularity problem also causes the thyroid problem I just outlined above. 

The bad news is that this system is very difficult to treat. 

We just don't have very many good treatments that target the hypothalamus or pituitary gland. 

So even though doctors know that these problems occur they just sort of scratch their head and don't have much to offer. 

#2. Disruption to Thyroid Conversion which Results in Low T3

Another direct method in which eating disorders impact thyroid function is through T4 to T3 conversion

T4 to T3 conversion is the process where your body activates thyroid hormone. 

If your body is unable to activate T4 into T3 then you will experience low T3 levels. 

And this is a problem because T3 is responsible for managing your metabolism and your weight

So as T3 levels fall thyroid function will also fall. 

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The good news is that you can measure your T3 levels by ordering the lab test free T3. 

The bad news is that the effects from category #1 cause a strange lab pattern that can throw doctors off

I mentioned earlier that eating disorders cause hypothalamic-pituitary suppression. 

This suppression manifests as a LOW TSH level or at least a lower than normal TSH level. 

Why is this a problem?

Because doctors associate a HIGH TSH with a low thyroid. 

In the presence of hypothalamic and pituitary suppression, your TSH may appear FALSELY normal (4) even though you are suffering from low T3 and other hypothyroid symptoms. 

This is the uncommon thyroid lab pattern that I mentioned previously. 

In order to catch this pattern, you must be aware of the impact that eating disorders have on your brain as well as thyroid conversion. 

It's only when you put both of these together that the thyroid lab pattern begins to make sense. 

Of course, to do this you will need to see a knowledgeable thyroid or hormone doctor

#3. Stress to the Body and Adrenal Glands

Numbers 3 and 4 affect your thyroid in an indirect way rather than a direct way. 

Anorexia and bulimia can directly impact thyroid function but they can also indirectly impact thyroid function by damaging it through other systems. 

In this case, I am specifically speaking about stress. 

It should come as no surprise that eating disorders cause stress to the body. 

As your body goes through a stressful situation it releases mediators, signaling factors, and hormones which impact another hormone known as cortisol. 

Cortisol is your primary stress hormone and excessively stressful situations can cause adrenal problems such as adrenal fatigue. 

And we know that issues in cortisol cause issues in thyroid function. 

So stress is one indirect way that your eating behavior can impact your thyroid. 

#4. Weight Gain

Lastly, you should be aware that thyroid function can be impacted by changes in your weight. 

People tend to think about eating disorders as behavior that almost always result in weight loss. 

But this isn't always true. 

In fact, many women with bulimia, for example, tend to be slightly overweight (5). 

And people who are actively being treated for anorexia will notice that they gain a significant amount of weight during this treatment. 

So it's not uncommon for people with eating disorders to have their weight fluctuate, sometimes significantly. 

And weight gain, from any cause, will have an impact on thyroid function. 

Extra weight gain alters leptin signaling, inflammatory levels, and hormones such as insulin, which alter thyroid hormone function and thyroid conversion. 

To complicate things further, it may be required to gain weight in order to fix the metabolism which was damaged from the eating disorder. 

The weight gain aspect of eating disorders can be tricky to navigate but is necessary in order to manage your metabolism and your thyroid. 

How Do you Treat or Reverse Thyroid Damage from Eating Disorders? 

What if you've had an eating disorder in the past and you are now suffering from the symptoms listed above? What then?

The good news is that you CAN be treated and your situation CAN be reversed. 

The bad news is that it can take a significant amount of time, usually on the order of several years. 

There are 3 main areas that you will want to focus on in order to reverse thyroid damage:

  • Repair your relationship with food - The first step is to overcome any issues you might have either with your body image or with food. If you don't have a handle on these aspects then whatever treatment you undergo may not be permanent and the longer you have an eating disorder the more damage it will cause. So get this under control first. There are many therapies out there that can be effective including cognitive-behavioral therapy (6) which can be very effective at changing your thoughts and therefore your behavior. 
  • Repair your metabolism - The next step is to repair your metabolism which will almost always require an INCREASE in the amount of food that you consume. And yes, this will probably result in some temporary weight gain. But this weight gain will be necessary in order to repair your metabolism and thyroid function and you should be able to lose that weight down the line. This is also why you must repair your relationship with food prior to this step. For many people, weight gain is something that can trigger binging/purging behavior. 
  • Take thyroid hormone if necessary - Lastly, you may want to seriously consider the use of thyroid hormone, especially pure T3. Pure T3 therapy, in the form of Cytomel and liothyronine, can bypass the thyroid conversion process and supply your cells directly with the thyroid hormone they need. In the case of my wife, pure T3 therapy in the form of liothyronine was very important for her treatment. She didn't see significant improvement in her metabolism or her mood until we added this therapy in. 

The Bottom Line

While the consequences and impact that eating disorders have on your thyroid can be long-lasting and severe, you should not give up hope!

There are ways to treat and repair the damage as outlined above. 


The longer you binge/purge/avoid food the more damage you will cause to your body. 

So if you are currently struggling with that process make sure you get it under control as soon as possible. 

Seek help out immediately and don't be afraid to enlist the help of your loved ones and family. 

Now I want to hear from you:

Do you have a history of an eating disorder in your lifetime? Even if it was decades ago?

If so, do you feel that your eating disorder played a role in your current thyroid problem?

Have you been able to get the lab testing that you need to evaluate your thyroid?

Have you seen improvement in your metabolism or thyroid function with the recommendations I've listed above?

Leave your questions or comments below! 

References (Click to Expand)

the connection between eating disorders and thyroid problems

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About Dr. Westin Childs

Hey! I'm Westin Childs D.O. (former Osteopathic Physician). I don't practice medicine anymore and instead specialize in helping people like YOU who have thyroid problems, hormone imbalances, and weight loss resistance. I love to write and share what I've learned over the years. I also happen to formulate the best supplements on the market (well, at least in my opinion!) and I'm proud to say that over 70,000+ people have used them over the last 6 years. You can read more about my own personal health journey and why I am so passionate about what I do here.

P.S. Need more help? Check out my free thyroid downloads and resources.

20 thoughts on “How Eating Disorders Cause Thyroid Problems – HPA Dysfunction”

    • Hi Lesley,

      It can, but only if you overfast. Some fasting, provided it is not too much, can be beneficial to the thyroid.

  1. I have a history of yo-yo dieting and binge eating. In the past when I lose weight I feel so miserable at a lower bod weight that I gain it all back, like my body wants me to be 200lbs and I’m only a 5’6 female. I’m on armor + levo and my labs now show that I’m in the high end of the normal range for both Total T3 and free T4 but my TSH is so low now it doesn’t even register. When I started my TSH was in the normal range and both total T3 and free T4 were low. I’m still having symptoms and haven’t been able to lose any weight even with improved labs. Any thoughts on where I should go from here? My doc doesn’t seem to want to test free T3, reverse T3 or Leptin. Thanks so much for any advice!

  2. Such an interesting article. I’ve been exactly through it. I’ve been diagnosed with PTSD after 1 year of severe anorexia that made me end up in intensive cares. At that point, my t3 level were 0,0003 (belgian norms) so inexistant. I went through the 3 phases of healing. I had to make sens of my eating and be at peace with food. Then I had to accept all the weight i gained back while i was adding T3 to my treatement. I think it is awefully sad how belgian doctors have no knowledge ln thyroid. My T3 had gone down for 3 years, i made it notice to my doctor who told me that as long as my tsh was in the norms, i was fine. I hope people here could study through you. Thanks a lot

  3. Hi Dr. Westin Childs,

    Have you ever talked about scalloped tongues in regards to hypothyroid?

    I’ve been hypo for four years but for the past 10 months, my doctor made a pretty big error in my meds while switching me to NP thyroid. I was undermedicated and along with all the typical symptoms I got a pretty dramatic scalloped tongue.

    I’m mostly curious about how long it might take for the tongue inflammation to reverse.

    Thank you!

  4. The available literature seems to indicate that those suffering with something Iike Bulimia will have lower serum levels of leptin. This is confusing, if leptin resistance is indicated by high serum leptin levels, how could both groups suffer from a slow metabolism?

    • Hi Stacy,

      Both low leptin and high leptin impact the body in the same way so it doesn’t really matter if your leptin is low or if you have high leptin with leptin resistance, both conditions lead to a slow metabolism and inability to lose weight. Also, just for what it’s worth, my own personal experience in treating women with bulimia suggests that they do indeed have high leptin levels, not low leptin levels. But in either event, it wouldn’t really matter for the reasons listed above.

      • I have a 28ish year history of anorexia nervosa. I believed I started developing this around 11, and at 20 I was diagnosed with papillary thyroid carcinoma. I’m curious if there is any research as to whether there is any correlation between endocrine cancers and inconsistent nourishment?

  5. Hi Dr. Childs,

    Great article! I have hypothyroid and I would tell people that I must have blown out my thyroid from all the years of suffering from an eating disorder as kind of a joke. I always thought it had something do with that.

    I am currently on amour and love it, I feel like a normal person. No mood swings, my energy is back and I able to keep my weight in the normal range. Before the meds I could not lose weight no matter what I did.

    Just a side note, do you know if eating disorders cause circulation problems?
    I always have cold feet another problem I blame on the eating disorder.


    • Hi Andrea,

      Eating disorders cause thyroid problems which can cause cold extremities which may contribute to that particular problem!

  6. This is what I am going through, I think. I have 20 years of severe anorexia.
    My thyroid is starting to get in range. It is very frustrating.
    Some doctors say not to treat this? I feel better on liothyroine but it’s hard to get doctors to agree.

    • Hi Nikki,

      Most doctors agree not to treat it but I feel differently. If you can see symptomatic improvement with thyroid medication then I think it’s worth it. They aren’t living day to day in your shoes so it’s impossible for them to know how it feels to be you.

  7. Dr. Childs- I initially believed my thyroid problems started with the death of my daughter in 2004, but I now realize that it was being abused growing up, then developing Bulimia in high school, bad marriages, Anorexia in college, followed by the horrible stressor of loss. I also pushed myself for 3 years following the loss doing distance cycling (kind of therapy for me). I still struggle with energy. I have Cortisol imbalances, low Adrenal functioning, weight gain (about 15 pounds more than I need). I follow a very healthy diet. Thanks for this article because it broadens my knowledge of why I have the problem.

  8. HI doctor.
    When I was 19 year old İ lost 18 kilos whithin two hair fell out and the color faded.A year later I started doing sport and my hair started to come out again. when i stopped they fell out again. After 3 years I went to military service and started to do sport and my hair came out again very black and live like before 19 age.
    Now I am 32 year old and my hair falls out but when I start doing sports it comes to life and starts to come out. As well as my eyelashes. And the yellowish color of facial skin comes to life.After meeting you, I realized that the reason for all this is related to the thyroid and metabolism.
    TSH (Thyroid-stimulating hormone) 3,662 µIU/mL (0,3 – 4,2)

    TSH (Thyroid-stimulating hormone) 1,978 µIU/mL 0,3 – 4,2
    FT3, sərbəst triyodtironin (Free T3) 3,05 pg/mL 2 – 4,4
    FT4, sərbəst tiroksin (Free T4) 0,83 ng/dL 0,54 – 1,24
    The above two results apply to the same laboratory
    13.12.2021-this is the result of another laboratory
    (TSH) 2,27 uIU/mL 0,35 – 5,6
    (FT3) 5,03 pmol/L 3,1 – 6,8
    (FT4) 9,16 pmol/L 7 – 20

    16.12.2021 and this is the result of another laboratory
    (TSH) 2,81 µIU/mL 0,27 – 4,2
    (a-TPO) 13,02 IU/mL < 34
    Anti-tireoqlobulin (a-Tg) 112,9 IU/mL < 115
    (fT4) 15,9 pmol/L 12,0 – 22,0

    If possible, I would like to know if the symptoms of hypothyroidism, such as hair loss and nail weakness, fast weight gain (for the first time these symptoms occurred as a result of an acute diet) are eliminates by exercise. Is the problem here related to the conversion of t 4 to t3 or Could it be related to thyroid dysfunction ?

    Thanks for this kind of explanatory articles and videos.
    Greetings from Baku (Azerbaijan).

  9. I mentioned this on another one of your blogs but I grew up with a mother who didn’t eat much and needless to say I was underfed. Thinking this was normal, the under eating behavior continued into adulthood which eventually progressed to thyroid dysfunction and I lost half my thyroid and the result from losing that half was a severely low appetite.
    Over three months I’ve increased my calories trying to get at least 1800-2000 per day. I gained 20 lbs fast. A lifetime of under eating will not be repaired in a short amount of time.


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