You’ll read that you shouldn’t break a long fast with a heavy meal because of refeeding syndrome but does it even effect us if we break with a high fat high protein meal?
I reckon you only ever get the electrolyte issue if you break with carbohydrates.
Pure speculation on my part so I’m happy to be wrong.
The longest I’ve ever fasted was 5 days and I broke with eggs and nothing negative happened.
Of course n=1 though.
Thoughts?
I don’t get that anymore. I’m vegan at times too. I’m not sure of the science behind it though. I heard or read it was electrolyte and I’m fanatical in that area.
I used for fast 4.5 days a lot, and ate a normal meal. The worst that happened with me was that my body freaked out in terms of going to the bathroom.
Now, I have some bone broth, wait, a small “meal”, wait, then another small meal. That has helped.
I also wonder if refeeding syndrome is longer then 1 week, like a month?
It would be exceedingly rare for it to be anything but after a VERY long fast. Months, for most people.
The last study I saw - was done on over 10,000 hospital patients, and the incidence of low phosphorus in the blood (which is what ‘refeeding syndrome’ usually is) was 0.43% (from memory). And these were people who were already in the hospital. 
Over time, during fasting the insulin level drops. We’re not digesting anything from outside the body that requires insulin once it gets in the bloodstream, and burning our own fat has very little effect on blood sugar/the need for insulin.
The body gets used to the low insulin environment, and the balance shifts toward using fatty acids and ketones for energy. Electrolytes are not entering the body in the quantities they do when we’re eating (usually).
To an extent, the body gets depleted of electrolytes. Most of this takes place within cells, not outside of them. Blood concentrations tend to remain in the normal, healthy range. The cells themselves contract, which keeps the electrolyte concentration within them okay, too.
If we break a long fast with a big meal of very insulin-requiring stuff, like carbohydrates, then the body responds by producing a lot of insulin. Insulin’s main job is to ‘unlock’ cells and move energy (glucose from the bloodstream) into them.
The body isn’t used to all this insulin, all of a sudden, after a very long fast. The insulin also pushes electrolytes out of the bloodstream, and into the cells. This is the problem - if the blood level of electrolytes falls too low, it’s a real problem, potentially even fatal.
But it’s almost never a real concern, unless the fast has been very long. Just ‘taking it easy’ when starting to eat again is the deal. Somebody - even hospitalized people - dying from refeeding syndrome is very, very rare.
I think bone broth is a great thing to start with. Or any relatively small amount of protein and fat. Just not 4 liters of orange juice or a dozen baked potatoes or something…
I once broke a 12 day fast by eating 4 Burger King Whoppers, buns and all… Not very intelligent, and certainly not keto nor really sensible in any way. Felt a little sluggish, like the body was struggling with it all, but that was it.
Whether you keto / carni is irrelevant, reefed syndrome is from people hitting actual starvation level and staying there for too long. I’ve done 8 days and then ate the house. That said, don’t fast that long. Not worth it.
whoa…I had a hard time with a normal meal after 4.5 days. But that might be just me.
Bob, I’m not at all saying that people should disregard caution. A hard time when initially eating - makes sense even with fairly short fasts.
I would think it’s going to take hours, certainly, at least, before the body is back to ‘normal.’ Maybe a day or two.
Get some food in the stomach, then the small intestine, have stuff being absorbed into the bloodstream. Have the pipeline be ‘full;’ again.
@OldDoug Well, if you (or anyone) can do it, that’s great. It’s so much more satisfying to eat something real.
And I think I may be an exception rather than the rule. I’m a little less like this now, but when I first started fasting the longer 4.5 day fasts, I would immediately stop going to the bathroom (#2) on the second day. And nothing would happen to my first meal, then it seemed like my body immediately woke up with a vengeance.
Now, I’m a little less like that. Not sure if it’s age, repair to my system, or what, but I tend to go to the bathroom more during the fast and less after the first real meal.
@lfod14 I’ve restarted some long fasting because it’s the only thing I know of that reduces insulin. The lowest insulin value I ever got was after 4.5 days fasting. I still have > 10 fasting insulin, which most people say means you’re insulin resistant. I don’t know how to get less insulin resistant other than through longer term fasting.
If we had pin-prick insulin monitors, I could do some real testing. Try an insulin test, then eating higher fat, lower protein. See what happens daily. Then try higher protein, lower fat. Dairy one week, no dairy the next week. Tons of tests I’d love to do, but getting to a lab is difficult and now more expensive here in CT. .
I saw people on this forum being careful after just a few days because they were more sensitive… Keto didn’t help with that. It’s individual but of course, a very long time without food changes everyone and we should be careful then.
I ate sugar after my longest fast but not much and it was only 5 days (I have no idea why my body wanted sugar but maybe it was my love towards fruit as I had an exclusively fruit meal first. Quite odd as I had no sodium since 5 days and I felt funny… Again, I don’t get it but my desires were clear. It was decades before I went low-carb, I wouldn’t expect this now!).
After just a 2-3 day fast I eat normal but if my body wants less, so be it. I follow its guidenace. Even 23 hours can be long enough for my body not to want a proper, OMAD sized meal again, my mealsize diminishes on OMAD and it falls apart though it goes better nowadays… But broth or just a few eggs? I would starve!
Refeeding syndrome is mostly tied to severe malnutrition and the insulin spike from suddenly reintroducing carbs, yeah.Breaking a fast with keto/carnivore foods is generally a lot gentler metabolically. But technically it can still happen after very long fasts or in already malnourished people, even without carbs. 5 day fast for a healthy person usually isn’t where it becomes a big concern.