Why does my stomach and gut protrude when I have an underactive thyroid?

There are two causes: 1) You are getting fat, 2) You have reduced gastric motility, which causes the stomach and intestine to protrude.

I am going to talk about abdominal distension. I will only touch briefly on the body fat.

Increased Body Fat From Hypothyroidism

This happens because your thyroid (which is effectively the engine of the body) operates at a slower rate, due to lower levels of thyroid hormones. All chemical processes in the body are governed and magnified by the amount of thyroid hormone in your body. That just doesn't affect your personality and other issues such as fatigue; it affects your basal metabolic rate. When severely hypothyroid, this can be reduced as much as 30 to 50%. The only way to not get fat when you are hypothyroid is to eat less calories, or correct your thyroid hormone levels.

There are no excuses. If you are underactive (hypo), you must eat less, or you will get fat.

There are no excuses. If you are underactive (hypo), you must eat less, or you will get fat.

When you are underactive or going through a period of change and not in a state of regular thyroid homeostasis, all sorts of bad things happen to the body - the wear and tear on your organs is proven to shorten your life.

In this article, I am going to talk about why the stomach/gut/belly not only protrudes (frontwards) but also distends (laterally). It makes you look like a teenage mutant ninja turtle.

Having said that, unless you are an athlete and have under 10% body fat, you probably won't even notice it. Except you may feel constipated and bloated.

But, if you're like me, you want to look your best undressed, on the beach or even on the stage, you most certainly will.

Gastric and digestion motility

It appears to be the case that thyroid hormones are near directly proportional to your rate of digestion motility. If you're hypo (running slow), food will stay in the stomach and intestines and easily accumulate - even on the same day.

I am going to show you some photos of myself below, which are taken within days of each other. In the left-most column, I will have a thyroid belly. The right column will be within 2 - 3 days later of taking T3 (fast-acting) to rid me of kilograms of "stuck" food, which alters my appearance significantly.

Before the images, I am going to address the Question: Why not just take your thyroid HRT medication and why doesn't it stay the same each day?

Answer: When training hard, using supplements, gaining muscle (lean body mass) and reducing body fat, your dosage absolutely cannot remain the same. It must be modulated. Your UK endocrinologist probably won't help you with that - he'll tell you to stop training.

I have tried everything from glutamine, probiotics, super hydration, fibre to prebiotics. Nothing moves the food through the intestine until thyroid levels are corrected. I have been battling this for Twenty years and I still make mistakes.

Those who are informed may wonder whether I have been abusing bodybuilding drugs such as human growth hormone and insulin - I have not. This is thyroid-related.

Aldosterone

So, I'm pretty certain the MOA of thyroid hormones being out of homeostasis is stimulating the aldosterone receptor as well (the hormone which determines salt and fluid retention). But if this theory were correct, a fat face and significant subcutaneous water would ALWAYS coincide rather than sometimes. So, I'm not certain. But I do recall one endocrinologist prescribing me epleronone for days when I had a fat face and had a social event - it is an aldosterone receptor antagonist, therefore the theory does make sense.

Images of thyroid belly / abdominal distension - note there is NO significant change in body fat between the side by side images