Curious observation


Background: hypothyroid male taking levothyroxine, in ketosis for the last 5 months (“strict keto”), primary goal weight reduction but enjoying the other health benefits.

My basal temperature has always been low for as long as I can remember: usually 1.5- 2F lower on waking, rising through the day to 0.75F lower (than what is considered normal or average).

On keto I noticed fairly early on that my waking was around 0.75F low and rising to normal during the day.

A curious change has taken place over the last couple of weeks. My waking basal temp while still on the low side is rising much faster than before. When I eat I move to +0.5 - +1F within a few minutes and this effect lasts for a couple of hours.

It’s not a concern, in fact I’m quite pleased about it. Searching through the literature it could be something to do with how I process nutritional protein when in ketosis. Or it may be something to do with my body happy to “waste” energy it doesn’t need.

I’d be interested in other views :slightly_smiling_face:


Typically a sign of a lowered metabolic rate, which clearly fits here. Keto could be making your body happier, but T4 takes a while to work, it’s not instant like T3, plus your conversion rate comes into it which many docs suck at by always prescribing T4 and not a low dose of T3 to go along with it.

(Bob M) #3

I gotta say body temperature is not great for anything. I still am 97.5 every time I check, yet am at the lowest weight I’ve been in 20+ years.


In my experience it is impossible to get a doc to prescribe T3 here in the UK.

In the run up to my next routine thyroid function test I plan to reduce my T4 dosage to see whether keto, or more specifically lowered insulin/insulin resistance, has improved my thyroid function. Again though, getting TSH and T4 levels is easy but getting T3 levels is not here, so I’ll have to guess whether my T4 > T3 conversion is ok or improved.


Is that the same low temp right through the day Bob?

(Bob M) #6

Depends. Here’s one day with eating (blue) and one day fasting (orange)


The problem was that I was looking for a cold temperature, but I haven’t had that while fasting for a while. Not sure why not.

And I took my temperature for a bunch of days, until I couldn’t see the purpose. The original plan was to try Brad’s ideas of Fire in a Bottle, but I found that everything I tried from him gave me side effects. So, I stopped.

(Bacon enough and time) #7

There is a hypothesis that on a ketogenic diet, the body uses the thyroid hormones much more efficiently.


I read that all the time from the UK guys on the bodybuilding forums, side effect of gov’t healthcare. Don’t feel bad, we’re not (that) much better in the US when it comes to Thyroids, doc’s completely suck at them. I’d advise going private, most TRT clinics are also into that as well as anti-aging as well and do Thryoids right. Many also choose to just do it on their own.

Going private sucks because you’re paying out of pocket, but the treatment isn’t even comparable. You can also get your own labs done for everything, even over there.

See if this place is ever around you.

It’s owned by Dave Crosland, the bodybuilder, they travel everywhere and will check anything you want. If not, TRT clinics should all also deal with Thyroids. Or that nice Indina Pharmacy online :wink:


Yes, I’ve looked into that Paul but haven’t found any concrete evidence, just hypothesis.

Anecdotally though, having been hypo for 25+ years I have a “feel” to what my thyroid hormone levels are at any one time, hypo or hyper. For the last little while I have felt on the edge of hyper even though my blood levels don’t reflect that. Could be that as you say, I’m using what I have more efficiently.


I’ll look into that. Not come across that before

(Little Miss Scare-All) #11

I’m currently on 100mg of brand Synthroid for hypothyroid. Started Keto on 112mg, so after 1 year (now currently 3), the doctor dropped me down to 100mg and my blood has been good and steady.

Pre-keto, my avg body temp was around 97.5 F, give or take. After 3yrs, I can proudly say I’m often close to 98.6 F. My low body temp always irked me. I mean, I have leaned up, built muscle, meditated daily, used crystals lol, so there are other things to consider, but Keto seems to have been the key to a return to normalcy, or as normal as i’ll ever get :joy: