Keto and Hypothyroidism: A Treatment You Might Have Missed

The Ketogenic (“Keto”) Diet has grown in popularity significantly over the past several years. While low-carbohydrate diets have been around for a long time, The Keto Diet is something a little different. In addition to involving a different dietary strategy, The Keto Diet is also unique in that it is a medical therapeutic diet that can be used to manage certain health conditions, such as hypothyroidism.

Hypothyroidism is a complex, multi-factorial illness that is rarely caused by just one thing. However, dietary strategies can play an important role in management of the condition in a couple of key ways. In this article, we will explore what The Keto Diet is and how it differs from other low-carbohydrate dietary strategies. We will also discuss hypothyroidism and the diversity of subtypes, as well as how The Keto Diet touches on those unique parameters. Then, we will explore how The Keto Diet is helpful in addressing the specific types of weight gain seen in hypothyroidism, the autoimmune drivers of hypothyroidism, and the gut health issues that drive thyroid problems in general. Last, we will review the drawbacks of The Keto Diet, given that it is not appropriate for everyone.

What Is The Keto Diet?

The Keto Diet is a dietary strategy that shifts a person’s metabolic pathways. Ordinarily, metabolism works like this: we eat a well-rounded meal, and our bodies break down the food into individual macronutrients, and then further into sub-constituents. For example, proteins break down into amino acids, carbohydrates break down into simple sugars, and oils break down into fatty acids. Usually, our bodies primarily use carbohydrates for cellular fuel. The enzymes in our digestive systems break down the carbohydrates into simple sugars, which enter into our cells (with the help of insulin) to be further broken down into electrochemical ions that power up our cells. Meanwhile, fatty acids and amino acids are used for tissue repair and synthesis of other biological molecules, like hormones. They also can be coverted into glucose through a process called gluconeogenesis when more cellular fuel is needed.

However, in The Keto Diet, rather than carbohydrates serving as the primary fuel source, fatty acids do. While low-carbohydrate diets all restrict dietary intake of carbohydrates (and subsequently, calories), The Keto Diet is different because it also strategically increases intake of dietary fat. In doing so, the body shifts its metabolic pathways to generate cellular fuel from fatty acid products called ketones instead of the typical sugar molecules. Whereas other low-carbohydrate diets may have a higher proportion of, say, protein, thereby allowing traditional metabolism through the conversion of amino acids to sugars, The Keto Diet requires a certain macronutrient proportion, limiting carbohydrates to typically fewer than 50g daily so that the body can shift over the course of a few days into a ketotic state.

When the body is in ketosis, it’s not just cellular energy production that changes; other parameters of physiology shift, too. For example, our brains are traditionally programmed to run entirely on glucose. When the body shifts to ketosis and the brain is forced to run on ketones, it also changes how the neurons in our brains fire. Different neurotransmitters are released. Signals are more controlled. Likewise, ketosis shifts immune function, which creates a suppression of the Th2 division of immune function, which is implicated in autoimmune conditions. In individuals who have trouble controlling their blood sugar and experience inflammatory side effects, the lack of carbohydrates allows their inflammatory conditions to be better controlled. Finally, because The Keto Diet involves ketones as fuel instead of glucose, insulin is not needed for cells to produce energy. This means that any of the other bodily processes driven by insulin (such as production of sex hormones and certain adrenal hormones) also are not produced the same way. This may be beneficial or harmful depending on what else is going on with a person’s health.

What Is Hypothyroidism and What Is The Root Cause of Hypothyroidism?

Hypothyroidism is a condition in which the body is not sufficiently able to regulate metabolism because of a deficiency of brain stimulation of the thyroid, response of the thyroid to said signaling from the brain, or responsiveness of the body’s tissues to the signals sent by the thyroid. More specifically, there are several subtypes of hypothyroidism which include primary hypothyroidism (a damaged or otherwise ineffective thyroid gland), autoimmune hypothyroidism (in which the body attacks the thyroid, causing damage), stress-induced hypothyroidism (where chronic psychological or physical stress suppresses the thyroid’s production of hormone), disorders in which the body lacks the ability to use thyroid hormone on a cellular level, exposure to toxins that damage cells or the thyroid itself, liver problems that affect transport of thyroid hormone, and nutrient deficiencies that deprive the body of the building blocks it needs to synthesize thyroid hormoen. I wrote a comprehensive post titled The Root Cause of Hypothyroidism which I encourage you to read if you have not already.

Because the thyroid is responsible for regulating metabolic function, symptoms of hypothyroidism reflect a decreased metabolic state, such as impaired fertility, weight gain, hair loss, depression, fatigue, constipation and more. The Keto Diet is uniquely equipped to help reverse these symptoms and also may help address the underlying root cause of the disorder.

How The Keto Diet Can Help Reverse Hypothyroidism

The Keto Diet was initially popularized as a weight-loss strategy, and it is certainly effective for weight loss. However, it is uniquely appropriate for treatment of hypothyroidism in a couple of key ways, which depend on the root cause of hypothyroidism. In this section, we will outline how The Keto Diet helps address both the symptoms and underlying root cause of hypothyroidism.

How The Keto Diet Treats the Root Cause of Hypothyroidism

In functional medicine, the goal is always to treat the root cause of a condition rather than to simply mask over the symptoms. In the traditional medical model, the treatment for hypothyroidism is hormone replacement therapy, classically with the drug levothyroxine. This may be essential for some people regardless of the root cause, and regardless of concurrent, conservative management strategies. However, in many cases, we can reduce the need for medication or potentially alleviate the need for it completely. Here’s how The Keto Diet can treat the root cause of hypothyroidism, of course dependent on what the root cause actually is:

1. The Keto Diet suppresses autoimmunity: Because The Keto Diet shifts metabolic pathways, it suppresses the Th2 division of the immune system, which is the more aggressive, “fight-stuff-off” part of the immune system. In cases in which the root cause of hypothyroidism is autoimmunity, for example Hashimoto’s Hypothyroidism, suppressing the immune system is beneficial. Immune suppression calms the tendency of the immune system to attach the thyroid, which reduces inflammation of the thyroid and improves its function. Controlling the immune system in this way also helps with the other inflammation-driven symptoms of Hashimoto’s, like body aches, fevers, and fatigue.
2. The Keto Diet improves gut function: Consuming sugar is a primary driver of intestinal dysbiosis, a phrase that refers to imbalances in good and bad bacteria in the gut. While it is not the only driver, sugar tends to increase everything from problematic commensal bacteria, to pathogens and the harmful yeast, candida. Sugar also negatively impacts the body’s ability to fight off pathogens (a different pathway from the immune suppression seen in The Keto Diet) which increases the likelihood of needed antibiotics, which most certainly are not helpful for gut health.
   • Fiber: Additionally, when done right, The Keto Diet involves an increased consumption of dietary fiber, which is a source of prebiotics that promote diversity and abundance of beneficial, gut-healing bacteria. Impaired gut function plays a tremendous role in driving multiple types of hypothyroidism. GI dysbiosis and resultant gut inflammation affects the body’s ability to absorb nutrients from food, which drives nutrient-deficiency hypothyroidism.
   • Gut inflammation also also worsens autoimmune conditions and creates inflammation, which drive Hashimoto’s hypothyroidism.
   • Hormone Metabolism: Poor gut health also affects metabolism of hormones, which is important in peripheral conversion disorders (refer back to The Root Cause of Hypothyroidism article) because the gastrointestinal tract is one of the primary places that the body converts the hormone T4 into the more active form, T3.
   • Detox: Finally, the increased dietary fiber in The Keto Diet (when done correctly) helps the body eliminate toxins through its normal detox pathways, which reduces the overall toxic burden and the resultant toxic effects to the thyroid.
3. Liver Function: One of the major drivers of liver problems in American adults comes down to insulin resistance and the development of non-alcoholic fatty liver disease. This inflammatory condition affects the liver’s ability to detoxify. The insulin resistance that also typically accompanies this problem has a similar negative impact on the thyroid for a couple of reasons. For one, insulin resistance tends to suppress the body’s ability to produce globulin proteins, such as thyroid-binding globulin, which helps transport thyroid hormone through the blood stream and deliver it to the tissues that need it. Insulin resistance is also associated with driving the metabolic-fertility condition PCOS in women, which is associated with increased likelihood of hypothyroidism. Insulin resistance is also a major driver of inflammation and stress on the body, which has implications for hypothalamic hypothyroidism. Because The Keto Diet all but completely eliminates the need for insulin, it plays a significant role in controlling these insulin-related problems and their implications in liver and thyroid function.

How The Keto Diet Treats the Symptoms of Hypothyroidism

In addition to addressing many of the root causes that drive hypothyroidism, The Keto Diet can also be helpful in controlling the symptoms that accompany hypothyroidism, regardless of the individual root cause.

1. Weight Loss: While not everyone who struggles with hypothyroidism experiences weight gain, for those who do, hypothyroidism can make it even more challenging to lose weight. The Keto Diet is accompanied by a calorie deficit because of the increased fiber intake and decreased consumption of highly palatable but not-so-filling foods (namely, ultra-processed carbohydrate foods.) The Keto Diet also decreases appetite because of the shift to emphasize satisfying fats and oils and slow-to-digest fiber and protein. It also eliminates the influence of insulin in driving appetite and associated blood sugar swings which cause sugar cravings. All of these help promote weight loss in those who need to lose weight.
2. Anti-Inflammatory: By suppressing the Th2 division of the immune system, The Keto Diet reduces inflammatory processes in the body. Inflammation is associated with everything from fatigue to depression, and this anti-inflamatory effect of The Keto Diet can help control these associated symptoms.
3. Fiber + Digestion: The Keto Diet, in some people, causes loose stools because of the increased oils and the metabolic shifts. The accompanying intake of high-quality vegetables and fiber also bulk up stools and promote elimination. Because constipation is a common symptom associated with hypothyroidism, this stool-softening, stool-bulking effect of a Keto Diet done right significantly alleviates hypothyroidism-associated constipation.

Drawbacks of The Keto Diet in Treating Hypothyroidism

The Keto Diet is a wonderful means for controlling the symptoms of hypothyroidism and may even be helpful in addressing the root cause of hypothyroidism, depending on what is driving it for a given individual. However, it is not a panacea and also may not be appropriate for everyone. Because The Keto Diet affects metabolic pathways in the whole body, it may actually cause new problems for some people. In medicine, the first pillar is to do no harm, so it’s important to recognize when The Keto Diet is not an appropriate treatment for hypothyroidism.

1. History of Eating Disorders: Relationship to food matters for health in significant ways. The Keto Diet places significant restrictions on types of foods consumed, which may trigger a new eating disorder or a relapse in susceptible individuals. The dietary thought and considerations involved may create preoccupation with food, anxiety, binge eating, and other problematic factors in the food relationship. I do not ever recommend extreme dietary modification in my patients who are at risk of disordered eating.
2. Fertility: The Keto Diet may suppress fertility in women, even when still having regular periods. Many women need to consume a certain number of carbohydrates (typically around 150g ) in order to maintain healthy, ovulatory menstrual cycles. This is mediated separately from reduced body fat percentage, which is also a consideration. Particularly for women who do not need to lose weight, the decreased body fat that comes with The Keto Diet may negatively impact fertility and menstrual cycles. Not having menstrual cycles is dangerous to a woman’s health if she has not yet reached menopause.
3. Nutrient Deficiencies: Because nutrient deficiencies can worsen both hypothyroidism and numerous other health conditions, it is important to ensure a nutritionally adequate diet when following a Keto Diet. When not done correctly, The Keto Diet can produce new nutritional deficiencies, which is problematic on its own.
4. Other: It’s also important to note that even though The Keto Diet may improve lab markers and certain symptoms of hypothyroidism, some people just generally feel worse on that diet than they do when the consume moderate amounts of healthy carbohydrate foods. It’s always important to listen to your body and trust your gut when evaluating a given medical intervention. If you feel worse on a Keto Diet, it is not appropriate for you.

Overall, the Keto Diet is a commonly overlooked treatment for hypothyroidism that could help control symptoms and reverse the underlying root cause that drives hypothyroidism. Many doctors do not discuss this option with their patients, which is another reason that functional medicine is such an important part of the medical system. If you are concerned about your hormones or your thyroid, talk to your doctor about whether The Keto Diet is a good fit for you in managing your hypothyroidism.

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I’m Dr. Alexandra MacKillop, a functional medicine physician, food scientist and nutrition expert.

I specialize in women’s health & hormones, addressing concerns like fertility, PCOS, endometriosis, dysmenorrhea (painful periods), PMS symptoms like bloating and mood changes and more.

If you’re looking for a new way to approach your health, I’m here to help you through it. Click to learn more.