Hello everyone,
I was listening to some video linking extended fasts with metabolic ketoacidosis. Upon digging further I found a couple of reports (mostly anecdotal to be honest) like this one https://www.amjcaserep.com/download/index/idArt/917226 .
There were also medical reports of metabolic ketoacidosis during preoperation fasting.
Anyone has any more information on this or on how to avoid such deleterious effects during prolong fasting ?
The case report mentioned there is poorly written and of little or no substantial value, in my opinion. In at least one instance, the lack of proof reading has part of a statement saying the exact opposite of what was intended. College kids just trying to get something published?
Fabien, that case was a "60-year-old male with a history of well-controlled diabetes
mellitus type II," - just about exactly like me, but I’ve fasted for as long as 12 days and have no worries about it, and I would think that you are light-years safer than me. 
I don’t think you need fear any deleterious effect, here.
A titanic number of people, both Type 2 diabetics and non-diabetics, regularly fast for as long as that case or longer, and I have never heard of a case of ketoacidosis among them (possibly until now, anyway). The report is about one guy who fasted for 5 days, then ate soup and took a chlorophyll supplement. Who knows? As you said, ‘anecdotal,’ and the same for another instance - their reference #4 - where they make their case that “Malnutrition and poor dietary intake are ways to enter a state of starvation that may result in ketoacidosis.”
That case was an anorexic woman who had not eaten for several days. To project from such cases onto the general population is a bit far from rationality, IMO. It’s quite a leap to get to “fasting can cause ketoacidosis.”
I’ve fasted for 14 days. No problem. I suspect the acidosis in the case cited was related to the victim’s diabetes. It may have been ‘well controlled’ but regardless, any number of things could occur. So I’m betting diabetic ketoacidosis here.
In nutritional ketosis ketones are produced as needed. Your metabolism only accesses sufficient fat stores to meet your energy requirements of the moment and converts some into ketones in the process. As long as there’s insulin, there is not going to be ‘runaway’ ketone synthesis. Ketones that aren’t used are generally ‘dumped’ via breath and urine. Something has to be disrupted and/or not functioning correctly in order for ketone concentration to rise to the level of acidosis.
This is interesting:
Could be, but to me it’s at best a ‘never say never’ deal - impossible to prove that’s not the case, but still extremely doubtful, IMO. If he was Type 1, then it would be easily believeable, but for Type 2s only taking Metformin, it’s essentially ‘not a thing.’
It looks to me like he had not fasted before, then slammed right into 5 days of it. It wasn’t the fasting that messed him up, it was when he started eating again - he had soup and took a chlorophyll supplement. He was used to taking the chlorophyll, but perhaps not with such an empty system as after 5 days of fasting, and it’s a known side effect of chlorophyll supplements that they can cause nausea and vomiting.
So, he feels sick, vomits, gets dehydrated, feels dizzy and passes out, hits his head. I wish they had tested him for blood ketone levels - that would be illuminating. The report says, “As acid anions, beta-hydroxybutyrate and acetoacetate can result in a decreased blood pH (acidemia), if present in higher levels.” Okay, so tell us what the ketone level was. All I see is them saying his urine was “2+ ketones.” Sheesh…
In his case, though I’m no kind of a doctor, I’d tell him to forgo the chlorophyll when breaking a fast, probably ease into fasting, i.e. try 1 day then 2 then 3… and consider stopping the Metformin when not eating, or reduce the dose - he ought to run it by his doctor - and stay hydrated.
Yes, that tells us nothing about β-Hydroxybutyrate and acetoacetate concentration in the blood. We have folks here on the forum who have higher numbers on the pee stix.
Yes I had noticed this and initially thought it could be a form of refeeding syndrome. That being said, although the conclusion seemed heavily influenced by the possible prejudices the doctors had against the keto diet + fasting, it didn’t occur to me that maybe the diagnosis of what was causing nausea and vomiting could be completely off the mark.
If would be very unusual for someone with a functioning pancreas to develop ketoacidosis, since the insulin produced should keep the blood pH under control. There is a condition called euglycaemic ketoacidosis (which, unlike diabetic ketoacidosis, is not accompanied by a rise in serum glucose), but that generally occurs only in people taking certain drugs (SGLT-2 inhibitors, for example) or in women on a ketogenic diet who fast during pregnancy or lactation.
If they were only measuring the patient’s urinary ketones, that is not a good indication of the level of ketones in his blood. I was under the impression that a diagnosis of ketoacidosis required measuring serum β-hydroxybutyrate and serum glucose.
I suspect that this is actually a case of misdiagnosed re-feeding syndrome, and his real problem was an imbalance of potassium.