Why Keto and Very Low-Carb Diets May Not Be the Best Choice for Hashimoto’s
- Dec 31, 2024
- 4 min read
Updated: Jan 26
When managing Hashimoto’s thyroiditis, your diet plays a crucial role in supporting your thyroid, reducing inflammation, and promoting overall hormonal balance. While ketogenic and very low-carb diets are often praised for their benefits in weight loss and blood sugar control, they may not be suitable for everyone, especially those with Hashimoto’s.
In this article, we’ll explore why these diets might not align with the needs of someone managing this autoimmune condition and what alternatives may be better suited to your health.
Understanding Hashimoto’s and Thyroid Health
Hashimoto’s thyroiditis is an autoimmune condition where the immune system mistakenly attacks the thyroid gland. This eventually can lead to hypothyroidism, where the thyroid doesn’t produce enough hormones to regulate metabolism, energy levels, and other essential bodily functions.
Supporting the thyroid is vital, but many people overlook how diet choices, particularly very low-carb or ketogenic diets, can also impact thyroid health.
Insulin and Its Role in Thyroid Hormone Conversion
One of the lesser-known factors in thyroid health is the role of insulin in hormone conversion. The thyroid primarily produces T4, an inactive hormone that must be converted into T3, the active hormone your body relies on for energy, metabolism, and proper cell function.
Insulin, the hormone released when we consume carbohydrates, plays a key role in this conversion process. Low-carb diets, including keto, significantly reduce insulin production because carbohydrate intake is minimal. This can impair the T4-to-T3 conversion, potentially leaving the body with insufficient active thyroid hormone.
For individuals with Hashimoto’s, this can exacerbate symptoms like fatigue, brain fog, weight gain, and sluggishness.
The Impact of Low-Carb Diets on Cortisol Levels
Low-carb diets can also increase cortisol, the body’s primary stress hormone. When carbohydrate intake is restricted, the body relies more heavily on fat for energy, a process that can trigger a stress response. Elevated cortisol levels are problematic for thyroid health, as they can suppress thyroid function, increase inflammation, and disrupt the delicate hormonal balance needed to manage Hashimoto’s effectively.
For someone with an autoimmune condition, chronic stress, whether emotional, physical, or dietary, can worsen symptoms and make recovery more difficult.
Carbohydrates: An Essential Macronutrient for Thyroid Health
Carbohydrates often get a bad reputation, but they are an essential part of a healthy, balanced diet, particularly for individuals with thyroid issues.
Glucose, the primary energy source derived from carbohydrates, is vital for supporting energy production and maintaining proper thyroid function.
Healthy carbohydrate sources such as sweet potatoes, squash, root vegetables, fruits, and whole grains (if tolerated) provide steady, nutrient-rich energy. These foods also help regulate insulin levels, which supports thyroid hormone conversion and overall hormonal balance.
Balancing Blood Sugar Without Going Too Low-Carb
While stable blood sugar levels are important for managing Hashimoto’s, extreme carbohydrate restriction is not the answer. Instead, a moderate, balanced approach that includes healthy fats, proteins, and fibre can help stabilise blood sugar without putting the body under unecessary stress, depriving the body of the glucose it needs for thyroid and immune system function.
Why Keto May Not Be Sustainable for Hashimoto’s and Thyroid Health
The ketogenic diet, with its focus on extremely low carbohydrates and high fat intake, can work well for certain individuals.
However, for those with Hashimoto’s, the lack of sufficient carbohydrates can lead to unintended consequences:
Impaired thyroid function due to reduced T4-to-T3 conversion.
Increased cortisol levels, which exacerbate inflammation and stress.
Nutrient deficiencies if the diet isn’t carefully balanced.
For individuals with an autoimmune condition, a diet that places additional stress on the body or requires constant adaptation may not be sustainable or supportive in the long term.
A Better Approach to Supporting the Thyroid: Balanced, Individualised Nutrition
Rather than adopting a one-size-fits-all diet like keto or very low-carb, those with Hashimoto’s benefit most from a personalised approach to nutrition. A balanced diet that includes nutrient-dense foods from all macronutrient groups can support thyroid function, stabilise blood sugar, and reduce inflammation.
Key components of a thyroid-friendly diet:
Healthy carbs: Include sweet potatoes, parsnips, squash, berries, and gluten-free whole grains (if tolerated).
Protein: Choose high-quality sources such as grass-fed meats, fish and eggs. We tend to lean on animal sources when we refer to protein rich foods as these do a better job at stabilising blood sugar and providing a wide range of vitamins and minerals.
Fats: Incorporate healthy fats like oily fish, avocados, olive oil, and nuts.
Anti-inflammatory foods: Add leafy greens, cruciferous vegetables, and omega-3-rich fish like salmon, sardines and mackerel.
Personalised Support for Thyroid Health
At The Autoimmune Clinic, we understand that no two health journeys are the same. That’s why we work with you to develop a nutrition and lifestyle plan tailored to your specific needs.
We help you identify triggers driving the autoimmune process behind your Hashimoto's, whether that be dietary, infections, lifestyle or environmental exposures while ensuring your nutrition is suiting both your autoimmune and thyroid health.
Whether you’re managing Hashimoto’s or other autoimmune conditions, our goal is to help you restore balance and feel the best you can. It is possible to feel well even if you are managing an autoimmune disease.
If you’ve been considering keto or very low-carb diets but feel unsure if they’re right for you, we can help you understand what a more balanced, sustainable dietary approach looks like for you that supports your thyroid and overall health.
