gmpicket wrote:I'm struggling with the fasting thing, too. I've cut back my sugar intake substantially - not all gone, but much much much reduced. Added lots of fat (nuts, tuna, eggs, olives, & extra dark chocolate). I feel like I eat enough. But some nights my body goes hypoglycemic (doing glucose blood test with meter - and some mornings ok with 83 , while other mornings 68 or 72). Some nights I can't make it 8 hours without having to eat some emergency chocolate. Other nights I go 13 hrs ok. I'm guessing this is going to take some time for my body to adjust. (I had a BMI of 18.25 when I started, so my body doesn't have much stored fat to burn.)
Possibly you have some hyperinsulinemia. See the reprint of Joseph Kraft's paper
Catherine Crofts did her PhD thesis
on Kraft's 15,000 data points over his career. She was trying to figure a simpler way to see if someone had hyperinsulinemia without a full five hour glucose tolerance test with insulin assay that Kraft did. She determined that an insulin test two hours after the glucose intake would tell a similar story with <30 being the cutoff for not having hyperinsulinemia. I recently asked her about how much leeway one could have over the 2 hours. She said +/- 15 minutes. " If longer either way, use some good engineering principles to extrapolate whether or not there is a risk of an issue."
My personal experience, with a BMI of 24 and a DXA scan showing my body fat is in the lowest 1st percentile for my age for all limbs and torso, is that being well keto-adapted makes fasting easy. 13 hours is a short time to worry about not having enough fat, in my opinion. My general advice to people who want to fast is to keto-adapt by lowering their total carb intake. I did it in 2009 the traditional Atkins way of 20g carbs/day for a number of weeks till I was adapted. Volek and Phinney's book
is a good reference, especially about making sure you have enough electrolytes, especially sodium but also potassium and magnesium.
I have maintained this keto-adaptation since 2009, even though my carb intake is generally much higher. On multi-day fasts, I have dropped my blood sugar as low as 31 mg/dL (1.7 mmol/L) however ketones were at 6.0 mmol/L. As per the research, I had no cognition issues whatsoever. On p 2760 of this paper
they show the results of fasting subjects for 50 days, THEN giving them insulin and dropping their serum glucose to as low as 0.5 mmol/L (9 mg/dL). The subjects had no cognitive issues at all. Note their average serum betahydroxybuterate was around 8 mmol/L (though even levels around 0.5 mmol/L will stave off hypoglycemic issues. See graph here:
From May 1 2017 to Jan 31 of 2018, I did 19, 120-hour fasts. I maintained weight stability when looking at the first day of a fasting cycle to first day of the next. I also have fasted 22 hours/day on eating days since June 2015.
I'm not suggesting you should do what I do, only that I'd look to an insulin profile that is not a Type I as shown in Kraft's paper as a possible cause.
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