Intermittent Fasting: help me logic this article

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yarwell

they read zero too, or at least mine does. Quite often in fact.

broseidonkingofbrocean

I don't think scientific study proves IF being that beneficial in humans and the benefit is just being in a deficit. However I do use IF and it helps me out when I start a cut and it has produced results for many others who had trouble with a regular diet. With any diet give it a try and see if it works for you. Everyone thinks their diet is the best one but the best diet for you is whatever diet works for you.

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yarwell

shell1005 wrote: »

yarwell wrote: »

they read zero too, or at least mine does. Quite often in fact.

Well then you use a different meter then the one that they used at the research hospital. 0.1 mmol was the lowest it registered.

Either that or someone was making stuff up. Can't say I've met many (any ?) lab instruments of any sort where you can't zero them with distilled water as part of calibration. Obviously 0.1 is the lowest non-zero reading if it only does 1 decimal place but I'm not convinced despite the appeal to authority.

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Crisseyda

I said that according to UpToDate, which is the evidence-based, peer-reviewed clinical decision resource that I use at my work, the average person will be in mild ketosis after 10-14 hrs of fasting, which equates to a blood ketoacid level of 1 mmol/L.

@stevencloser showed a study where children fasted overnight had blood ketoacid of 0.1 mmol/L? So... when we fast our patients overnight for procedures, the standard start time is midnight--that's pretty late to start a 10-14 fast. Midnight is pretty universal, and actually when I worked at a pediatric hospital there was even more leeway because children get cranky! So how long were those kids fasted? And how many kids were there in the sample size? I realize you're trying to disprove UpToDate for some reason. You're incredulous to believe that people can switch to fat metabolism so quickly or that they start to create ketones that quickly after switching to fat metabolism.

stevencloser

Yarwell did, not me.

Btw. I found where the problem was. Wiki used mg/dl so I googled how that converts to mmol/L and it said they're interchangable, when actually 1 mg/dl is 0.1 mmol/l.
So yeah, normal amounts in people not in ketosis are 0.1-0.2 mmol/l.

According to yarwell's source, overnight concentration of ketones is not increased.

Wikipedia defines Ketosis starting at 0.5 mmol/l but calls the range between the 0.2 and 0.5 "mild ketosis".

When in a severe deficit additionally (from e.g. starving) concentration reaches 3-5 and people suffering from ketoacidiosis go above 12.
http://srmuniv.ac.in/sites/default/files/files/KETONEBODYMETABOLISM.pdf (page 36)

lemurcat12

stevencloser wrote: »

Yarwell did, not me.

I was just about to point this out. As for the question about the length of the fast, the study Yarwell linked addressed that too -- 12 hours.

Crisseyda

FASTING KETOSIS — The hepatic generation of ketone bodies described in the preceding paragraph is the normal physiologic response to fasting. Mild ketosis (ketoacid concentration of about 1 mmol/L) generally develops after a 12- to 14-hour fast. If fasting continues, the ketoacid concentration continues to rise and peaks after 20 to 30 days at a concentration of 8 to 10 mmol/L (mmol/L is used here rather than meq/L since meq/L does not apply to acetone, which has no charge). Beta-hydroxybutyrate is the major ketone body that accumulates [3-5].

3. Reichard GA Jr, Owen OE, Haff AC, et al. Ketone-body production and oxidation in fasting obese humans. J Clin Invest 1974; 53:508.
4. Cahill GF Jr. Fuel metabolism in starvation. Annu Rev Nutr 2006; 26:1.
5. Owen OE, Caprio S, Reichard GA Jr, et al. Ketosis of starvation: a revisit and new perspectives. Clin Endocrinol Metab 1983; 12:359.

From UpToDate