Discoveries never end, I guess. I have to believe that RMR is variable while fasting, just from the difference among feeling warm, normal, cool or uncomfortably cold.
For there to be a generalized decline in TDEE with RMR holding steady seems like a contradiction to me - how could this actually be?
I also experience the cold when eating but in strong ketosis due to a 0-carb diet so I attribute it to the lack of carbs and ketosis more than to fasting per se.
Fasting just get us to ketosis faster and deeper.
Update: Took 9+ days but my ketones are finally burning hot: 6.2, and GKI at 0.73
Herb, congratulations on your great progress so far, and on your enthusiasm too. 
I think there’s a lot of individual variation at work. Except for messing around in the 1980s, my first fast was 2 years ago, and on the 3rd day my feet felt cool, not uncomfortably cold but just enough that it felt good to get under the covers when I went to bed. Other than that one day, I have yet to feel cold during a fast. And of course many people feel cold regularly once they get to a point in a fast.
I haven’t noticed any ‘coldness’ while eating keto, even zero-carb, yet there is a difference. A lot of carbs will have me feeling hot and a mighty sweaty pillow in the morning. Can’t say it’s a bad thing - eating like a maniac, I only gained 5 lbs per year when it should have been 50.
Still have more-than-ample fat insulation around most of my body, and that presence, along with lots of energy available from so much fat, surely keeps me relatively warm while fasting.
58 hrs in and going to the gym in a few minutes. Slept the best I have ever slept when fasting. I have a new pillow and a new chair. I sleep in the chair at the end of the night, most nights. Both are helping. My sleep arrangements are complicated.
Will decide on breaking fast this morning or not after my gym workout.
Also fasted weight this morning was 198lbs. Woot, Woot!
Wow, you guys have been super busy while I was MIA…
I was sick the last few days (my lungs were rattling beautifully with every breath I took), stuck at home with a chestcold and messed up sinuses and didn’t go to work.
It probably would have been best to fast, I wasn’t really hungry at all but my mean brain wanted comfort, it doesn’t like to feel lonely.
My brain went on this morning when back to work. My usual “what is on the office kitchen table is not food” did not work as usual and I gave into some rhubarb cake carbage
I can probably not work out for the rest of the week until my lungs are better, so I want to start with a fast right away. an IF of 20h is the minimum I want to achieve to get back on track, 48h or even 58 would be even better…
Well, resting metabolic rate is just that - what your body expends if you were strapped to a bed. Running the machinery of life. So that can remain unchanged while the TDEE goes up and down.
It sounds like you are taking care of yourself and your lungs first. 
I broke my fast at 60.25. I was a little light headed at the gym after some resistance training. Could be BG or BP. Probably BP since yesterday was 111/68. I also realized I have an appt for teeth cleaning today and have to take a handful of antibiotics because of CVD. I don’t want to take them on an empty fasted stomach.
Refeeding is going well and I’m trying to eat a little and wait for my satiety signal. It tends to be 15 to 20 mins delayed.
Even though I cut this short I feel like it was my best EF so far. Hunger intensity was a problem at 45-48hrs and I handled it. Fasted wt 198 (oh my, so happy) and felt great. Brain fog is lifted. Productivity and calmness abound. Life is good for me.
I don’t fully understand it, but it seems as though the body responds to fasting with an adrenal response to keep energy levels high. Norepinephrine and epinephrine are what give people new to fasting the “fasting high”. I think we develop a tolerance over time, but I can remember that for my first 3-4 fasts I had difficulty sleeping because I was so wired.
I think that when we develop a tolerance for the adrenal response to fasting, that’s when the RMR variability comes into play. To be less euphemistic, I think we may develop adrenal resistance in much the same way we develop caffeine resistance. That’s just speculation on my part though. I don’t really understand 99% of this stuff.
Here is a study the explains the RMR regulatory mechanisms in a bit more detail:
I don’t either, Doug. On rare occasions, I have gotten slightly cold hands whilst Fasting. I know I read a lot of other folks mentioning this, but have only experienced it myself a few times now. … As to getting heated, or having the ‘sweaty pillow’ I can’t say this hasn’t happened, but I also don’t load up on carbs, so not sure if it’s the same or not? If I ever go over 20 carbs daily, it can’t be by much, unless this can happen on a lower scale? Say 25 carbs? … But I find it intriguing and will be keeping an eye out now.
Sorry to hear you’ve been under the weather, hope you feel better soon. 
Awww thanks Dave. Feeling better already… well enough that I actually want to punch everyone at work again 
.My goal is that I get back at full strength on sat.
Also I can’t wait for a few days off around easter.
Are you tracking blood pressure?
Fasting lowers blood pressure and running with lower blood pressure requires a higher heart rate…
You might check that.
Boxed last night. Great night.
Lowest ever (IIRC) GKI 0.47 Glucose 52 Ketones 6.2 DrBozRatio 8.4
Little sore from boxing but nothing serious.
Weight still going down: 206.5
FYI: Except for tracking things, I generally can just forget I’m on a fast.
I feel like one of the only IFers in here, lol. I’m going for one 39 hour fast this week.
Question for all of you EFers here. What do you allow during your fast? I see different people saying different things. I know some will have a BP coffee… Some will occasionally do bone broth. I’ve only ever water/black coffee/black tea fasted. Other than sipping on a warm mug of Himalayan salt water, I don’t imbibe in anything with flavor. This is probably why I haven’t yet crossed over 40 hours yet.
You’ll probably find that most here, are indeed IF’ers, when not fasting Extended times. … For instance, I’m usually doing OMAD, when not doing Extended Fasting, so generally will just eat 1 meal in the evening, during the weekdays, and have two meals on most weekends. Sometimes I do run OMAD all week, and others I will try to through in TMAD for a week. (My main objective is to keep things mixed up, to keep the body guessing so it can’t adjust to any set schedule or feeding time. Which it will and can do easily)
For me, I’ve always been pretty much water only. But have in the past drank Tea and an occasional Coffee. (Both plain, nothing added though.) I’ve actually never had a BPC or Bone Broth so can’t speak on them) And I still will drink a Tea or Coffee if the desire hits, but I’ve just come to enjoy loosing all the flavors whilst Fasting, as you mention above. So I seem to enjoy this time-out from flavors.
Edit to add… Forgot to mention, that I too drink 2 KetoAides when I Fast. I drink one each morning daily, but when Fasting, do one in the morning & one in the evening. Forgot until I read Mame’s post.
It varies for me by fast really. I want to fast ‘clean’ with water and black coffee only (ketoaid 2x a day) because it does seem to make a difference to my body, craving levels and mind hunger. However if I am white-knuckling a fast in the late evening I will use what I call a booster (don’t like the word crutch). It’s usually bacon or olives. This keeps my GKI very low <1 and enables me to keep on with the fasting benefits.
I crave the easy fast but thus far that happens for me rarely. So I have played around a lot to find out what will work for me… I decided the results were more important than some kind of fasting purity. I don’t want to grow to dislike fasting because it feels so amazing when it’s working for me.
Well the week so far has been fasting-wonky. It is so lovely to have a few minutes to be able to catch up on this thread and feel inspired.
I was really hoping that traveling for work by myself would make fasting Monday and Tuesday easier but it didn’t. At all. I had dinner(keto) both days. I have lots more work travel coming up next month.
Perhaps I will assume those days will be IF/OMAD to save me stress and frustration.
If anyone has tips on how to fast 24+ hours while traveling for work I would love to hear them.
I don’t have an issue with staying on my eating plan but darn it I wish I could find what would make fasting easier for me.
Anyway. I lift on Friday morning so I want to be well-fasted for that. So Wednesday evening until sometime Friday, 42+. Then regroup for next week is the current plan.
You’re not alone! There are lots of EFers, but I try to do two or three 42-hour fasts each week. I worked up to that over at least a month, starting with just one a week. I did do a 64-hour fast earlier this week, but it’s not something I really plan on doing a lot of. When I’m not fasting I do TRE somewhere around 16:8 or 18:6.
I’m not a super strict water-only person. From what I’ve read it isn’t necessary. Small amounts of fat or broth won’t affect your insulin response, autophagy is a scale, not an on-or-off thing, apoptosis happens as long as you’re eating under a few hundred calories, and so will weight loss. So, I’m okay not being strict. Other people want to go hard at it and not miss any chance for a small benefit that might be slipping by me.
I always have a couple of cups of very strong, black coffee in the morning. I’ve always drunk it this way for decades, has nothing to do with fasting. I’m not just doing that so I can leave out cream or something. My first fast I had a cup of bone broth at least twice, plus some tea with cream. Now that I’m into it more I might have a mug of broth around dinner time or tea with cream, but I generally don’t want both. If I’m feeling the urge, I might have a little bit of salt, but not usually.
Earlier this week, when I did my first longer fast, I did find myself with an empty, growly stomach around 8pm on the second night. I ate a couple bites of avocado as a stomach soother and kept on going until lunch the next day.
If you’re comfortable doing what you’re doing, I say keep doing it!
I have found for longer fasts I do need bone broth or HWC but if it is 36 hours or less I can usually push through with just water, black coffee and electrolytes. I agree with Zuleika, if these things help me fast longer then that is what I’ll do.
I am 20 hours into who knows how long. Just haven’t been hungry today. That being said, I have eaten well this week, imbibed quite a bit on the alcohol and I saw it on the scales this morning. I’m certain it’s not fat gain and just water but I probably will fast through tomorrow morning, which is when we leave to head to the beach. Happy fasting all!