I have recently started fasting a bit more. What I tend to do is eat normally (which is not that much although I don’t try to calculate the calories), then the next day I have tea and milk in the morning with a bit of collagen and then a piece of meat and some cheese (probably total about 200 calories) with my supplements (as I want to be consistent with the supplements and need some fat based foodstuffs to absorb the fat soluble ones). Then I move onto water and herbal teas for the rest of the day.
The first thing I get is perhaps a very mild headache around 9pm which is on the edge of a detox headache than can come quite strongly with a longer fast. Then I find I wake earlier which I assume is because my pineal gland is producing less endogenous melatonin (I don’t take melatonin before I go to bed). I normally use melatonin to get me back to sleep.
Now I know research indicates that autophagy interferes with the circadian proteins. Hence I am taking this to indicate an increase in autophagy.
I wonder what other people’s experience is with fasting causing sleep disruption and/or detox headaches. It would be quite useful to have a tool for measuring autophagy even if it is a simplistic as not sleeping that well.
Beyond fasting I am doing a number of other things on a daily basis to improve mitochondrial quality, but those have stabilised and if I am not fasting my first sleep is quite reasonable. There is a clear shift for fasting days.
The second thing I have noticed is that my HbA1c has moved up from the 4.4-4.6 range to 4.8-4.9. In the first week this happened I also took some D-Ribose which is known to glycate haemoglobin. Obviously the effect of this will last for a period of time. The first lab I used gave a same day response which is quite nice. The second lab had a day in the post for the sample. This has the tendency to reduce glucose and increase HbA1c as the sample metabolises in the post. So my HbA1c may have come down a bit.
However, I wonder if people have experience of fasting resulting in some increase to HbA1c. Alternatively it could be because I am drinking alcohol on fewer days in the week or taking less melatonin during the night. (remembering I am in the megadose territory - more precisely hectodose - viz 100s of milligrams or maybe decidose viz tenths of a gram, not millions though)
I only took D-Ribose on one day and the plan was an increase in ATP it was quite interesting and I probably will take it again, but i don’t think it is something to take chronically as cells are likely to adjust for it. (as well as the increases in HbA1c).
AIUI those are for people who are diabetic. My own glucose is according to two CGMs - this year - reasonably well controlled when not fasting and I think that actually the average glucose, therefore, may be higher than when not fasting.
I might test this with a CGM.
The complications are, however, that I know when I am drinking that drives down serum glucose as does melatonin.
FWIW, I recall hearing the explanation of this phenomenon as fasting is stressful, and causes higher adrenaline (“go find some food!”) which interferes with sleep. Higher stress (emotional or physical) levels could also cause higher blood sugar.
I am not sure the mechanism is right. Were there to be an increase in cortisol I would see an increase in heart rate. I would need to have a good review on fast days to say the situation here. What I identify is a disruption in melatonin generation. Cortisol can promote wakefulness, but the problem is not going to sleep, but waking early.
I think the headache has nothing to do with “detox” but is likely caused by dehydration. It’s very easy and common to get a little dehydrated when fasting because you’re not eating any salt.
As for sleep disruptions. I think it’s a combination of various factor that cause that like higher cortisol and higher anxiety. The body is basically telling you to stay alert to look for food.