Is Keto safe for thyroid?

What is the thyroid? The thyroid is in the base of the neck, and it’s controlled by the pituitary. The thyroid makes T4, but T4 is inactive. T4 has to be converted to the active form, which is T3. 80% of the conversion happens through the liver, and 20 % happens through the kidney.

How does keto affect thyroid function? When you go on a ketogenic diet, T4 will decrease up to 40%.

But let’s look at the big picture. There are no studies out there that show any negative effects on the thyroid when you go on a keto or low-carb diet. Also, despite the 40% drop, there is no drop in metabolism. T3 is becoming more sensitive and more effective.  I believe that high carb diets increase the need for more thyroid hormone, so T3 is higher. With a keto diet, T3 goes down, but I think that’s not actually abnormal. I believe that number is normal for what our bodies are designed to use. 

So, is keto safe for thyroid function? Yes. When you’re on the ketogenic diet, you’re actually improving the efficiency of the thyroid.