Feeling cold at night at the end of a 36 hour fast

[Chris24Main]

Anyone with an experience of this?

I've been on a journey all year since around January, gradually leaning in to Keto eating regime, and at the same time starting off fasting every alternate day, then easing off that after the first set of blood tests, to one fast a week, and now roughly once a fortnight, quite random and I also miss the occasional meal, to go longer between meals. I'm not snacking really at all, but might have some cheese or salami as I'm preparing a meal..

I'm not being very strict, except no sugar starch or seed oil. On fasting days - only water, coffee and salt. 36 hours from one dinner to the following day breakfast, so two sleeps.

I had plenty of visceral fat to get rid off to start with, but all my numbers are pretty much optimal now, so I tend to fast when my scales show an uptick in visceral fat, and it goes back down. Simple really, except that as the period between fasts grows, the more difficult planning becomes, and the hungrier I tend to feel between the lunchtime and dinner time on the actual fast - so overall while I'm fasting much less, in some ways it's more difficult to continue.

I still believe in the good of a 36 hour fast for Autophagy, and generally I feel so much better; blood glucose and insulin control only being one aspect of that.

Anyway (I can hear the cry of "get on with it!") - the question.

One of the things that's generally improving, is the thermal regulation of my lower legs at night, and leg cramping (in the feet, toes, and calf). I would have had to wear socks to bed to stave off the otherwise inevitable night cramps - but I don't now. That's all great.

However, more recently, I find that on fasting days, I'm quite cold all over, and on my last fast, I was up for hours trying to get my legs warm - nothing really worked at all, though I wasn't really cramping.

My thoughts are that overall, my vascular health is getting better - I have a readout for that on my scales, and it's pretty clear about this - that would explain the general improvement over the year. On the other hand, the general improvement in insulin resistance will lead to lower level of Thyroid hormone, and that in acute cases (and when it's genuinely cold, like now...) may lead to just feeling cold, in ways I don't normally.

Over time, improving sensitivity to thyroid hormone should sort it out, and if I know in advance, I can wear something to keep me warm on fasting nights.. it isn't a massive problem,

But - I wondered if anyone had similar experience ? - I think this will not be a thing for the 16:8s out there (and maybe that's also a good solution, just switch for the winter) as it's a combination of fasting and leading into night having already fasted for 24 hours.

It's really the first thing I've struck on this journey that's made me question whether my plan is optimal - I'm not sure a regular 36 hour fast is worth the massive sleep disruption. Any thoughts?

 

[Antje77]

I don't fast (except for often postponing my breakfast until late afternoon), but on days I haven't eaten much, and if I'm cold too for whatever reason, the quickest way to warm up for me is to eat something, even cold food works.

Can it simply be that our bodies prioritise other functions over keeping warm when it looks like not enough fuel is incoming?

edit:

Anyway (I can hear the cry of "get on with it!") - the question.

You? Long winded?
Never!

 

[Chris24Main]

Well, thanks @Antje77 - not too helpful, but at least I got a good laugh...

 

[Melgar]

@Chris24Main I’m going to come at this from a weird angle. You know how much this circadian rhythm thing interests me, well as you know the circadian system revolves around the light / dark cycle . And …… well my thoughts immediately went to the possibility that food also becomes part of the circadian process. Could it be that night time with no food for 36 hours may interfere with energy regulation and by extension your temperature regulation. Here is an extract from

Sleep and circadian rhythms: Key components in the regulation of energy metabolism​

Edited by Peter Tontonoz and Laszlo Nagy

“ A wide-range of less-easily observed rhythms occurs internally and includes the daily regulation of body temperature, adrenal corticosterone and pituitary hormone release, neuropeptide and neurotransmitter levels, sympathetic activation, energy metabolism (e.g., lipolysis, gluconeogenesis, insulin sensitivity, basal metabolic rate), as well as gene transcription.”

I‘ve tried to add the link to my quote, but for some reason I am unable to, but the name of the article is included in my post.

 

[Chris24Main]

Yeah.. I'm very much with you as far as circadian rhythm goes.. but this is.. once roughly a fortnight, on a pretty random basis. There is deliberately no rhythmn in fact.... also sleep itself is not affected. I'll read the article again though ...

 

[Resurgam]

I found fasting for over 12 hours didn't help, my HbA1c was higher than expected. I did lose some weight, but it was a normal HbA1c I wanted and did not get.
Recently - with the loss of the winter fuel allowance and it being cold so early in the season, our house has been colder at night, so I added a lightweight duvet on top of the normal one - I tried a second winter weight one, but that was too heavy on my feet. The lightweight one actually feels warmer, and I have noticed that my feet have shrunk down in size, plus I am sleeping better and more normal hours.

 

[MrsA2]

I work on only half a thyroid so have no idea whether that has any effect on the rest of my body. Any tests have me in the "normal" range for thyroid

However, since going low carb and losing 3 stone I am often cold, feet especially (apart from the times when I'm sweating hot often mid evening).
I've put it down to the loss of insulation and just cope by going to bed with a hot water bottle (or wheat bag) and by always wearing fluffy slippers after 60 odd years of loving going barefoot. I often have 2 or 3 blankets piled on top, much to hubbys disgust, but they tend to get thrown off in the early hours as my temperature rises to sweat level!

Your post raises interesting alternative possible reasons and I'll be interested to read what you find.

Meanwhile I'll just keep to my physical resolutions and suggest they may help you while your research continues.

 

[SimonP78]

I don't fast (except for often postponing my breakfast until late afternoon), but on days I haven't eaten much, and if I'm cold too for whatever reason, the quickest way to warm up for me is to eat something, even cold food works.

Can it simply be that our bodies prioritise other functions over keeping warm when it looks like not enough fuel is incoming?

I'm with you here, if I don't eat breakfast (FotF) and am WFH so get straight into doing computer work and I don't do any exercise (which would warm me up, as well as dealing with FotF - sometimes it can't be fitted in though) I also feel cold (and generally tired). I can certainly see the logic in your argument!

 

[MrsA2]

Addendum
Tonight I was out at social event so
1 food was consumed much later than usual
2 a few carbs were consumed
3 alcohol was drunk
4 walked there and back ( only 5 minutes each way but am usually sedentary of an evening)
5 feet are still warm now, whereas usually they would be cold

No idea which of these if any affect my circulation or temperature but am definitely different to most nights at this time

 

[SimonP78]

Alcohol has this effect - I think it's due to vasodilation, which means more blood reaches the skin, which then feels warm (though potentially also means you get cold quickly.)

Also exercise (probably due to a combination of vasodilation and certainly due to internal heat generation due to inefficient muscles.)

 

[Antje77]

I'm with you here, if I don't eat breakfast (FotF) and am WFH so get straight into doing computer work and I don't do any exercise (which would warm me up, as well as dealing with FotF - sometimes it can't be fitted in though) I also feel cold (and generally tired). I can certainly see the logic in your argument!

My thinking made sense to me as well, although I have no sources to back it up.
Getting warm almost instantly after eating when I'm cold looks significant to me, but it's up to @Chris24Main to see if he can find something useful on this information. Might be worth doing some experimenting with this on yourself @Chris24Main , even if it means breaking your fast early to see what difference it makes.

@SimonP78 , I do exercise most mornings before spending a while on the computer, but it doesn't really help to get warm, my exercise consists of open water swimming and I can assure you it doesn't warm me up at some 4 °C currently.

 

[DougDyl]

I found fasting for over 12 hours didn't help, my HbA1c was higher than expected. I did lose some weight, but it was a normal HbA1c I wanted and did not get.
Recently - with the loss of the winter fuel allowance and it being cold so early in the season, our house has been colder at night, so I added a lightweight duvet on top of the normal one - I tried a second winter weight one, but that was too heavy on my feet. The lightweight one actually feels warmer, and I have noticed that my feet have shrunk down in size, plus I am sleeping better and more normal hours.

I also use the double duvets at night. I also invested this winter in a single duvet with cover for the cold Scottish days for when sitting on the couch as my house can be very cold and you get scared to put the heating on.

 

[SimonP78]

@SimonP78 , I do exercise most mornings before spending a while on the computer, but it doesn't really help to get warm, my exercise consists of open water swimming and I can assure you it doesn't warm me up at some 4 °C currently.

Brrrrrr!

I wonder though, once you've recovered from the fact it's cold and dried off, etc., do you then feel warmer - from a combination of the exercise and also I wonder if ones body raises its "setpoint" and whether this reminds raised afterwards. Interesting stuff, would be good to find some journal papers, I'll do some Googling.

 

[Outlier]

I don't fast unless one counts time restricted eating - usually 20/4 but if I'm hungry earlier, I eat. I am always really cold first thing, and warm up a bit after my morning walk. But I do feel the cold and wear more layers than most people. I was like this before I lost my T2 weight as well, so for me, the midbody fat didn't insulate.

 

[IamResistance]

Hey There!
A good fella shown me this thread, mine was here.
Even though I don't feel cold, fasting makes me hypothermic. I just wonder if your body temperature lowers also.
My only discovery is that contrast showers help to prevent me from catching colds all the time. But I am in this business not for long time - 1.5 months, after I had a flu in October. I think that having these contrast showers help me feel energetic and even warm. Nonetheless, the thermometer shows I have hypothermia.
I don't know what to do here... I was thinking of exercising before bedtime, but it is said to have no effect. I'll try it for myself and measure the temp.

 

[jeano999]

Anyone with an experience of this?

I've been on a journey all year since around January, gradually leaning in to Keto eating regime, and at the same time starting off fasting every alternate day, then easing off that after the first set of blood tests, to one fast a week, and now roughly once a fortnight, quite random and I also miss the occasional meal, to go longer between meals. I'm not snacking really at all, but might have some cheese or salami as I'm preparing a meal..

I'm not being very strict, except no sugar starch or seed oil. On fasting days - only water, coffee and salt. 36 hours from one dinner to the following day breakfast, so two sleeps.

I had plenty of visceral fat to get rid off to start with, but all my numbers are pretty much optimal now, so I tend to fast when my scales show an uptick in visceral fat, and it goes back down. Simple really, except that as the period between fasts grows, the more difficult planning becomes, and the hungrier I tend to feel between the lunchtime and dinner time on the actual fast - so overall while I'm fasting much less, in some ways it's more difficult to continue.

I still believe in the good of a 36 hour fast for Autophagy, and generally I feel so much better; blood glucose and insulin control only being one aspect of that.

Anyway (I can hear the cry of "get on with it!") - the question.

One of the things that's generally improving, is the thermal regulation of my lower legs at night, and leg cramping (in the feet, toes, and calf). I would have had to wear socks to bed to stave off the otherwise inevitable night cramps - but I don't now. That's all great.

However, more recently, I find that on fasting days, I'm quite cold all over, and on my last fast, I was up for hours trying to get my legs warm - nothing really worked at all, though I wasn't really cramping.

My thoughts are that overall, my vascular health is getting better - I have a readout for that on my scales, and it's pretty clear about this - that would explain the general improvement over the year. On the other hand, the general improvement in insulin resistance will lead to lower level of Thyroid hormone, and that in acute cases (and when it's genuinely cold, like now...) may lead to just feeling cold, in ways I don't normally.

Over time, improving sensitivity to thyroid hormone should sort it out, and if I know in advance, I can wear something to keep me warm on fasting nights.. it isn't a massive problem,

But - I wondered if anyone had similar experience ? - I think this will not be a thing for the 16:8s out there (and maybe that's also a good solution, just switch for the winter) as it's a combination of fasting and leading into night having already fasted for 24 hours.

It's really the first thing I've struck on this journey that's made me question whether my plan is optimal - I'm not sure a regular 36 hour fast is worth the massive sleep disruption. Any thoughts?

I too suffer from cold legs and feet and often wear socks in bed - even during summer. I also often feel generally cold when doing a long fast. My nightly foot and calf cramps have not been so frequent recently - don't really know why but have lost over a stone in weight (taken 6 months btw). I am in the habit of using a hot water bottle in bed to help with warming my feet, legs, buttocks, hands, chest etc. I move it about till I am toasty. Watching TV in a warm room I use a blanket over my legs until I can kick it off when I warm up. Hubby says it is poor circulation - who knows?

 

[Chris24Main]

OK- so quick recap...

Not a general circulation situation - my general circulation is improving - I no longer need to wear socks at night, and my feet are warmer when I'm paddling on cold mornings.

So - that's all good, and maps to the expectation that low carb and low insulin and some autophagy should be improving vascular health.

then - due to the general lowering of blood glucose, and the greater ease of dealing with it over time, my body needs less thyroid hormone - which has 2 jobs -

1. helping to get glucose into cells (it's the thing that opens the Glut-4 receptor for anyone interested)
2. regulating mitochondrial action to control temperature - in brown fat cells (like normal fat cells, but specialised for heat generation)

So, the assumption is that I have acutely less thyroid hormone during the last stage of a fast, and so my brown fat cells are not being activated, and I feel (strangely - I mean it's kind of the opposite of feeling "strangely" hot when you have an infection) cold, when normally I should be warm.

as @Antje77 suggests - I'll be turning myself into another trial subject here - I've been perfectly toasty and slept well since my last fast, but I think it's the combination of long fasting (I'll lose 1kg or so, and very low blood glucose with high ketones, so quite an effective fast) and colder nights, and possibly in this case because I had no exercise in the afternoon before bed.

So - next time, I'll do that, I'll go for a walk (tend to do a 45 min with a slendertone belt on, so reasonable exercise, but nothing too severe) and report back on whether that made a difference.

 

[Antje77]

Brrrrrr!

I wonder though, once you've recovered from the fact it's cold and dried off, etc., do you then feel warmer - from a combination of the exercise and also I wonder if ones body raises its "setpoint" and whether this reminds raised afterwards. Interesting stuff, would be good to find some journal papers, I'll do some Googling.

Interesting questions and I'm curious on what you'll find!
Also off topic here so I'm taking it to this old thread on cold water swimming: https://www.diabetes.co.uk/forum/threads/cold-water-swimming-and-diabetes.200255/post-2738773

 

[LittleGreyCat]

Quick observation.
I tend to eat OMAD in mid afternoon.
If I haven't exercised that day I tend to get chilly in the evening.
Eating or drinking something warm can lift the chill, snuggling under a duvet less do.
Tentative conclusion: my body is going into the first stages of energy saving, where metabolic activity decreases.
Or hibernation, perhaps?
We keep the house warm around 20C during the day and not lower than 16C at night, so probably internal not external factors.

 

[Resurgam]

I was out shopping and spotted electric blankets !! in several supermarkets.

If they'd had anything other than single sizes left I might have been tempted.