Richard Sprague

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Prolon Fasting Mimicking Diet Day 2

Created: 2019-11-30 ; Updated: 2020-08-27

After a night of unusual dreams, I woke up with a headache, which though rare for me is not unheard of, so I don’t think I can blame it on the diet. I don’t think it’s lack of caffeine either; you’d think I’d have cravings if that were the case, but that’s not me right now.

It occurs to me that what I’m experiencing is the “keto flu”, an uncomfortable part of the adjustment your body makes from running on glucose and carbohydrates to being ketone-driven.

I may already be in ketosis. Testing in the morning, my Keto-Mojo meter registers 0.9 mmol/L, which is above the 0.5 mmol/L threshold for entering ketosis. Once I hit 1.5 - 3.0 mmol/L, I’ll have entered the ideal range.

Perfect Keto says I should think in terms of “GKI”, Glucose Ketone Index, which is calculated as

\[GKI = \frac{\frac{Glucose~level}{18}}{Ketone~Level}= Glucose~Ketone~Index\]

Since I was registering 79 mg/DL, that makes my GKI = 4.88

To get the most benefits from ketosis, you want to get your GKI number as low as possible.

I’m definitely feeling hungry today, though nothing I can’t handle. It feels a lot like the hunger from being sick in bed (come to think of it, maybe that’s more proof of the keto flu). I felt much better after the day 2 lunch of mushroom soup:


Figure 1: Lunch

Most of the afternoon was a blur of fatigue and brain fog. Yes, I’m hungry and thinking about food, but more than that, I find myself unable to articulate myself, and I frequently stumble over words that are on the tip of my tongue.

Dinner is more meager than yesterday but it helped a lot.

Day 2 Dinner

Figure 2: Day 2 Dinner

By bedtime, I was feeling much better. Not hungry, just a little fatigue.

My ketones are back down to 0.6 mmol/L with blood glucose at 83 (7.69 GKI).

Day 2 Glucose Levels

Figure 3: Day 2 Glucose Levels