"carnivorous diet" and "ketogenic diet": affecting thyroid levels.
What is dietary ketosis? It’s a state in which the body has shifted from a metabolism relying primarily on carbohydrates for fuel to one using primarily fat and ketones for fuel.
When does ketosis occur? The body enters ketosis if the diet does not provide sufficient glucose to replenish glycogen stores. Any diet which contains less than 100 grams of carbohydrate per day will induce ketosis.
Glucose sources. The major source of glucose in the body is from dietary carbohydrate. However, liver and kidney also produces glucose from glycerol, lactate/pyruvate and the amino acids alanine and glutamine through a process called gluconeogenesis.
Macronutrients and Ketosis. The total carbohydrate ingested and produced by the body shall not exceed app. 100g.
Carnivorous ketogenic diet. If the protein is not restricted to some degree (less than 140g daily or so) on a carnivorous diet, an excessive protein intake will generate too much glucose, impairing or preventing ketosis.
From the above notions we may conclude that carnivorous diet does not necessarily induces ketosis. Bearing in mind the amounts of meats consumed by hunter-gatherers or Inuit we may assume they were rarely if ever in the state of ketosis, despite the lack of straight carbohydrates in their diets for most of the time.
The low and no-carb diets are mostly feared by their adverse affect on thyroid. It’s been shown that T3 levels (active thyroid hormone) in the body are primarily
related to the carbohydrate content of the diet. It is possible that as with other hormones in the body (for example insulin), the decrease in circulating T3 levels may be compensated for by an increase in receptor activity and/or number.
However, the mentioned study examined the standard ketogenic diet which restricts protein intake. Hence, it may be assumed that if protein levels were kept higher, it could have disturbed the ketosis and prevented drop in T3.
Back in September 2009 I started a higher protein non-ketogenic carnivorous diet. I was eating about two pounds of fatty lamb daily and felt more or less fine. I was able to consume that much meat only because of
Liposomal Vitamin C that I was taking at the time. As soon as I dropped it at the end of October my digestive abilities began to fade away very fast. As the time went by I consumed less and less meat. Finally I had to settle with a half a pound of lean meat daily. The rest of my diet was complemented by fat. Unwillingly I progressed to a standard ketogenic diet. Naturally I had some serious concerns how such restrictive diet could have affected my thyroid hormones levels and my metabolism.
My thyroid panel dated
April 25, 2008 (just after I stopped Intermittent Farcing):
TSH – 1.33 (range 0.25 – 5.2)
fT4 – 17.87 (range 10.0 – 25.0)
fT3 – 12.64 (range 5.4 – 14.0)
My thyroid panel dated
April 26, 2010 (after 8 ZC months):
TSH – 1.43 (range 0.17 – 4.05)
fT4 – 18.9 (range 11.5 – 23.0)
fT3 – 2.5 (range 2.5 – 5.8 )
Anti-TPO – 20.3 (range 0 – 12.0)
Anti-TG – 22.3 – (range 0 – 30.0)
Mild to moderately elevated levels of thyroid antibodies may be found in a variety of thyroid and autoimmune disorders, such as thyroid cancer, Type 1 diabetes, rheumatoid arthritis, pernicious anemia, and autoimmune collagen vascular diseases. Significantly increased concentrations most frequently indicate thyroid autoimmune diseases such as Hashimoto’s thyroiditis and Graves’ disease.
In general, their presence suggests that there is autoimmune thyroid involvement and the higher the level, the more likely that is. Rising levels may be more significant than stable levels as they indicate an increase in autoimmune activity.
In spite of my higher than normal Anti-TPO the doctor told me that I don’t have Hashimoto’s. He may be right but I’d like to retest it sometime later when I have available funds.
My fT3, which were well normal two years ago, plummeted down on raw ZC diet. With such fT4 it undoubtedly signals to the altered thyroid metabolism which is call thyroid underconversion.
I wonder if higher protein non-ketogenic ZC diet would have prevented the drop in t3…
