Low Carb Eating and Your Thyroid

The thyroid gland produces hormones, primarily T3 (triiodothyronine) and T4 (thyroxine), which regulate metabolism, energy production, and overall body function. Thyroid hormones are influenced by various factors, including dietary intake, particularly carbohydrates.

Low-carb diets typically restrict carbohydrate intake to promote ketosis, a metabolic state where the body burns fat for energy instead of carbohydrates. While this can lead to weight loss and improved insulin sensitivity, it can also affect thyroid function in several ways.

How Low-Carb Diets Impact Your Thyroid

Decreased T3 Levels

Carbohydrates are essential for the conversion of T4 (inactive thyroid hormone) to T3 (active thyroid hormone). Insufficient carbohydrate intake may lead to decreased T3 levels, which can slow down metabolism and lead to symptoms of hypothyroidism such as fatigue, weight gain, depression and cold intolerance..

Increased Reverse T3

Low carb intake can increase the production of reverse T3 (rT3), which blocks the action of T3 and further disrupts thyroid function.

Stress Response

Prolonged adherence to low-carb diets may increase stress on the adrenal glands, which can further impact thyroid function. The adrenal glands and thyroid gland work closely together in regulating metabolism and energy production. Low-carb diets can trigger the body's stress response via the adrenal glands, leading to elevated cortisol levels. Chronic stress and high cortisol can suppress thyroid function and exacerbate hypothyroid symptoms.

Nutrient Deficiencies

Foods that contain carbohydrates are also often rich in other essential nutrients. Although you can absolutly get many of these nutrients from foods that are low in carbohydrates, including as much variety as possible in your diet has other health benefits separate to the effects on your thyroid (like feeding your microbiome). Carbohydrates are often rich in essential nutrients like fiber, B vitamins, and antioxidants. These nutrients support thyroid health and overall well-being. A lack of these can contribute to thyroid dysfunction.

Other nutrients central to optimal thyroid function

To support optimal thyroid function while following a balanced diet, consider including the following nutrient-rich foods:

Iodine-Rich Foods: Seafood (such as seaweed, shrimp, and fish) and iodized salt are excellent sources of iodine, a key component of thyroid hormones.

Selenium: Brazil nuts, fish (such as tuna and sardines), and lean meats are rich sources of selenium, which is essential for converting T4 to T3 and protecting the thyroid gland from oxidative stress.

Zinc: Include foods like lean meats, shellfish, seeds (such as pumpkin seeds), and nuts to ensure adequate zinc intake, which supports thyroid hormone production.

Complex Carbohydrates: Opt for complex carbohydrates such as whole grains (e.g., oats, quinoa, brown rice), legumes (e.g., lentils, chickpeas), fruits, and vegetables. These provide essential nutrients and fiber without causing rapid spikes in blood sugar levels.

Omega-3 Fatty Acids: Cold-water fish (e.g., salmon, mackerel), flaxseeds, and walnuts are rich in omega-3 fatty acids, which have anti-inflammatory properties that may benefit thyroid health.

So, the biggest thing to remember is that balance is key!

Instead of cutting out carbs entirely, aim for a balanced diet that includes healthy, complex carbohydrates like fruits, vegetables, and whole grains. These provide the energy and nutrients your thyroid needs to function optimally.

One important point to remember is that if you have autoimmune hypothyroid problems, it’s best to avoid gluten. Finding a quality gluten free bread (that is not nut based!!!) is super important

Remember, everyone's body is unique. If you're experiencing thyroid issues or considering a significant dietary change, chat with one of our naturopaths or nutritionists.

Our Nutritionists also specialise in the Metabolic Balance program. This program takes into account your health history and biochemistry to determine your optimal eating pattern and foods.