The ketogenic (or “keto”) diet is a low-carb diet emphasizing high-fat intake and largely limiting carbohydrates. Historically, the keto diet was developed as an alternative treatment for epileptic children and has been proven to reduce the number of seizures in patients with epilepsy.1 It also shows promise for use in treating other chronic illnesses, including diabetes, Alzheimer’s, Parkinson’s, and cancer.2 Given its potential health benefits, you may be wondering if you should try a keto diet if you have hypothyroidism. Here’s what I recommend.

The Keto Diet and Hypothyroidism

What is Hypothyroidism?

Hypothyroidism, or having an underactive thyroid, is when your thyroid gland does not produce enough thyroid hormone. Thyroid hormones affect nearly every part of your body, including your metabolism, brain, heart, muscles, hair, and skin. Without enough thyroid hormone, all of your bodily processes slow down to a sluggish crawl. Research shows that women and those with autoimmune diseases are more likely to develop hypothyroidism.3

The Role Your Adrenals Play

Chronic stress can also provoke hypothyroidism. Your adrenals produce stress hormones, such as cortisol. When you experience stress, a cascade of stress hormones signals your body to slow down all processes that are unnecessary for overcoming the stressor in front of you, including thyroid hormone production.

In our modern society, many of us experience one stressor after another with no time in between to physically recover. Chronic stress overworks your adrenals, which are unable to keep up with the constant demand for more and more stress hormones, inevitably leaving you in a state of adrenal fatigue. This flooding and eventual plummeting of stress hormones cause your thyroid activity to come to a screeching halt.

Adrenal Fatigue and Ketosis

The goal of a keto diet is to achieve the metabolic state known as “ketosis.” Depriving your body of its main fuel source, glucose (which comes from carbs), triggers your body to burn stored fat for fuel instead. It’s this fat-burning state of ketosis that is responsible for the rapid weight loss and enhanced energy and brain function people typically experience on a keto diet.

However, ketosis can be a major strain on the adrenals. Reduced carb intake leads to a decrease in thyroid hormone levels and an increase in cortisol—which decreases thyroid function further and means more work for your adrenals.4 If your adrenals are already fatigued, you do not want to stress them even more by going into ketosis.

This vicious cycle is why you should proceed with caution when it comes to a keto diet if you are hypothyroid, particularly if adrenal fatigue is one of the primary triggers of your hypothyroidism. For this reason, I would recommend avoiding a keto diet until you have addressed your stress levels.

Essential Nutrients for Thyroid Function

No matter which diet you choose to follow, if you have hypothyroidism, it’s important that your diet includes these important thyroid-supporting chemicals and nutrients:


Iodine is one of the two building blocks for thyroid hormones. Your thyroid converts tyrosine (the other building block) into thyroglobulin and attaches between one a four iodine atoms to create T1, T2, T3, and T4 respectively. Without enough iodine, your thyroid simply can’t produce its hormones.


The enzyme that converts T4 to T3 is a selenium-dependent enzyme, so without enough selenium, your thyroid hormones are stuck in their inactive state, causing hypothyroidism symptoms.


Like selenium, zinc plays a role in the enzyme needed to convert T4 to T3. Zinc is also necessary to trigger your hypothalamus’ thyroid hormone receptors, meaning that without enough zinc, your hypothalamus can’t accurately gauge thyroid hormone levels to increase production when levels are low. Because of these two factors, studies have linked zinc deficiency with decreased thyroid production and hypothyroidism. 


Iron contributes two key steps to thyroid hormone production. First, the enzyme that converts iodide to iodine (so that it can combine with tyrosine to become thyroid hormones) is dependent on iron. Second, like selenium and zinc, iron is required to convert T4 to T3.

How to Determine if a Keto Diet is Right for You

Everybody is different, so it’s important to listen to your body and know what you do or do not tolerate. You may do perfectly fine on a keto diet, or you might find your body doesn’t respond well to it. Either way, if you have hypothyroidism and are looking to experiment with a keto diet, be sure to consult your doctor first and monitor your thyroid levels closely during this time.

Because most thyroid conditions are triggered by autoimmunity, it’s just as important to determine if you should try a keto diet if you have an autoimmune disease. Whether you choose a keto, AIP, Paleo, elimination, or any other diet out there, by focusing on nourishing your body and giving it the nutrients it needs, you’ll be on your way to achieving optimal health.

Helpful Supplements for Adrenal-Thyroid Health

The best way to support your adrenals and accompanying thyroid problems long-term is to manage your stress. Realistically speaking, there will always be stress in your life but learning the tools and routines to leave a stressful situation behind after it’s over, instead of carrying it around with you, will reduce the physical effects of chronic stress. For additional support for adrenal-thyroid health, I recommend:

  1. Adaptogenic herbs help the body adapt and cope with stress. My go-to supplement to support the adrenal gland contains Rhodiola roseaPanax ginseng, and a number of other herbal extracts. I carry The Myers Way® Adrenal Support, in my store to promote a healthy stress response.
  2. All B vitamins are critical for the chemical processes within the adrenal glands, which makes my multivitamin ideal for adrenal support. It contains all 8 B vitamins in their pre-methylated forms.
  3. For added adrenal support, you can also take Omega-3 fatty acids, vitamin C, and magnesium.

If you are curious about your own adrenal health or would like further assistance in combatting your adrenal fatigue, I highly recommend seeking a Functional Medicine practitioner in your area.

Adrenal Support bottle

Article Sources

  1. Ketogenic Diet. Epilepsy Society.
  2. What Is the Keto Diet - And Is It Right For You?. . Better by Today. .
  3. Hypothyroidism (Underactive Thyroid). . WebMD. .
  4. Challenges with a Low-Carb Diet. . The Weston A Price Foundation. .