Extended Fast - why aren't I feeling cold?

(Andrea) #1

I’m an experienced faster. I’m three days into a 5 day fast (water and herbal tea only). It feels way easier than any other time I’ve fasted and I’ve lost 7lbs already. Strangely, I don’t feel very cold at all. Does anyone know why this could be? Thanks very much!

(Old Baconian) #2

I would imagine it has something to do with how well you were eating before embarking on the fast. But that’s just a guess on my part.

(Michael - When reality fails to meet expectations, the problem is not reality.) #3

Why do you think you should feel cold?


Around the 6:30 minute mark.

The action on BAT is most likely due to elevated growth hormone from fasting. WAT can be converted into beige adipose tissue and then acts somewhat like BAT. I don’t remember if it’s ketones or growth hormone that converts the WAT into beige adipose tissue.

(Andrea) #5

I’m not sure - I wasn’t eating particularly well. I use fasts to reset my eating habits and reexamine my relationship with food and nutritional goals. Prior to that, I had some life changes (a big move) and was eating some processed foods I don’t ordinarily eat (very small amounts of sugar and processed foods).

(Andrea) #6

Michael - usually, when I’ve fasted before, I’ve felt exceptionally cold. I don’t have the same level of coldness that I’ve had in the past this particular time. I was wondering if there was some metabolic or macronutrient thing I hadn’t considered.

(Michael - When reality fails to meet expectations, the problem is not reality.) #7

Note: Not too technical but still helpful. Open “SHOW MORE” in the Description to display links to studies mentioned in video in the References & Resources section.

PS: Maybe it has something to do with how much onboard fat you’ve got to work with. Or thyroid.

(Carnivore for the win) #8

That’s what was thinking. I feel cold, especially feet, when my thyroid is slow from not getting enough iodine.

Could be more salt, with iodine, in these processed foods, increasing thyroid function.

(Doug) #9

I think it’s an individual thing, and also that it can vary a lot for a given individual. Only a couple times in a lot of fasts and more than 4 years have I ever felt cold. I know that being ‘cold’ is the norm for many people, though (and I’d like to see how actual temperature readings match up with perceived feelings).

Have also had times of being extra warm. Not sure why this would be - ‘brown fat activation’ or the body really being well synched up with the fat stores and the process of burning that fat (for a change :smile:). A couple years ago, 5.5 days into a fast, I had about 20 minutes of feeling very warm on my upper torso and neck. It was really pleasant, but it did make me wonder what in the heck was going on.

(Bob M) #10

I think there are many possible options. I did too much fasting and became so cold that I had to stop fasting. I think that was likely my metabolic rate decreasing to protect the body.

At the time, I thought it might be my thyroid, so I got an extensive thyroid set of tests done and also started taking mega doses of iodine. (I can’t remember which came first.) But everything on my set of thyroid tests came out fine. And after a while, too much iodine seemed to cause heart palpitations.

I’m still afraid to take iodine, though I might restart this weekend with a drop or so.

Iodine is one of those things where there’s no good test for it. And even the tests there are (you take a huge amount of iodine, then gather up all your pee for 24 hours and send it to lab) have faults.

And if I look at symptoms for thyroid:

I basically had none of those. (Though I do sweat a lot…but always have.)

And, I only get cold when fasting. If I eat, I’m rarely cold.

I do still get cold when fasting, though it’s dramatically better than it used to be.


Prostaglandins(made from long PUFAs) as thermogenic compounds.



(Tad Sampson) #12

Feeling cold is normal for the body when fasting. The body reduces the blood flow to the extremities to keep the organs with better temperature and your brown fat.

I measure it and it really lowers the temperature. I took my temperature and it was in the normal range, but at very low level, borderline.

I hate that. I like cold (winter time), but feeling that fasting cold is different. It hurts in my hands.
I fight that with taking salt and water and then the temperature improves. The cold also stops when you eat.

(Bob M) #13

This is what I’ve heard Cate Shanahan say too: heat is caused by burning PUFAs. This is Cate: