One of the most common (non-food-specific) questions I get regarding ketogenic diets is whether or not keto can cause thyroid problems. Like many health and nutrition questions, there really is no simple answer here. As most of the questions I receive ask about hypothyroidism and ketosis, that is what we’ll address here. I recently had an experience with underactive thyroid, and was able to sit down with my doctor for a half hour consultation to discuss it. Some of the information provided here is from that session, and will be cited accordingly!
In this week’s podcast, Stevie and I discuss our own experiences with a slowed thyroid, and discuss how you can mitigate the potential negative effects of a low carb diet on thyroid function. It should be noted that this podcast is not intended to be medical advice, but rather is what we would do in a situation where our thyroids were slowed due to diet and lifestyle, as opposed to an autoimmune condition. If you suspect you’ve got a slow thyroid, definitely go talk to your doctor!
What is hypothyroidism?
As the name implies, hypothyroidism is when the thyroid under-functions, or is “slow.” While most of the time, a chronically underactive thyroid is caused by an autoimmune condition called Hashimoto’s, there are a few other causes. Iodine deficiency and overconsumption of goitregens can lead to a chronically underactive thyroid as well. During my chat with my physician, she wanted to point out that sometimes lifestyle (often lack of sleep and stress) and diet can cause a temporary shift in thyroid function, and isn’t necessarily indicative of a permanent state.
How is hypothyroidism related to keto and low carb diets?
This is the argument at the crux of the keto/thyroid questions, and it pretty much boils down to the unavoidable fact that your thyroid requires carbohydrates for proper function. This article has a great breakdown of how calorie restriction and sometimes carb restriction can actually impact the thyroid’s ability to produce T3 & T4, the hormones necessary for carrying out metabolic functions in your body. Because your thyroid will often downregulate production of these hormones when carbs are restricted (and especially in the presence of intense exercise), problems can arise, and that is what we are discussing in today’s podcast!
Links to studies mentioned are below. We hope you enjoy this show!
Studies linking carb/calorie restriction and low thyroid function: